Naval Expeditionary Runway Construction Criteria 海军远征跑道建造标准
P-8 Poseidon Pavement Requirements P-8 海神路面要求
W. Jeremy Robinson, Jeremiah M. Stache, Jeb. S. Tingle, W.Jeremy Robinson、Jeremiah M. Stache、Jeb.S. Tingle
March 2023 2023 年 3 月
Geotechnical and Structures Laboratory Carlos R. Gonzalez, Anastasios M. Ioannides, and James T. Rushing 岩土工程与结构实验室 Carlos R. Gonzalez、Anastasios M. Ioannides 和 James T. Rushing
The US Army Engineer Research and Development Center (ERDC) solves the nation’s toughest engineering and environmental challenges. 美国陆军工程研究与发展中心(ERDC)致力于解决美国最棘手的工程和环境挑战。 ERDC develops innovative solutions in civil and military engineering, geospatial sciences, water resources, and environmental sciences for the Army, the Department of Defense, civilian agencies, and our nation’s public good. Find out more at www.erdc.usace.army.mil. ERDC 在土木和军事工程、地理空间科学、水资源和环境科学领域为陆军、国防部、民用机构和国家公益事业开发创新解决方案。欲了解更多信息,请访问 www.erdc.usace.army.mil。
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Naval Expeditionary Runway Construction Criteria 海军远征跑道建造标准
P-8 Poseidon Pavement Requirements P-8 海神路面要求
W. Jeremy Robinson, Jeremiah M. Stache, Jeb S. Tingle, Carlos R. Gonzalez, Anastasios M. Ioannides, and James T. Rushing W.杰里米-罗宾逊、杰里迈亚-M-斯塔奇、杰布-S-廷格、卡洛斯-R-冈萨雷斯、阿纳斯塔西奥斯-M-伊万尼德斯和詹姆斯-T-拉辛
Geotechnical and Structures Laboratory 岩土工程与结构实验室
US Army Engineer Research and Development Center 美国陆军工程研发中心
3909 Halls Ferry Road 霍尔斯渡口路 3909 号
Vicksburg, MS 39180-6199 维克斯堡,MS 39180-6199
Final report 最终报告
DISTRIBUTION STATEMENT A. Approved for public release: distribution is unlimited. A. 批准公开发行:无限量发行。
Abstract 摘要
A full-scale airfield pavement test section was constructed and trafficked by the US Army Engineer Research and Development Center to determine minimum rigid and flexible pavement thickness requirements to support contingency operations of the P-8 Poseidon aircraft. 美国陆军工程研发中心建造了一个全尺寸的机场路面试验段,并进行了交通测试,以确定最低刚性和柔性路面厚度要求,为 P-8 海神飞机的应急行动提供支持。 Additionally, airfield damage repair solutions were tested to evaluate the compatibility of those solutions with the P-8 Poseidon. 此外,还测试了机场损坏修复解决方案,以评估这些解决方案与 P-8 海神的兼容性。 The test items consisted of various material thickness and strengths to yield a range of operations to failure allowing development of performance predictions at a relatively lower number of design operations than are considered in traditional sustainment pavement design scenarios. 测试项目包括不同的材料厚度和强度,以产生一系列失效操作,从而在设计操作次数相对少于传统养护路面设计情况下的情况下进行性能预测。 Test items were trafficked with a dual-wheel P-8 test gear on a heavy-vehicle simulator. Flexible pavement rutting, rigid pavement cracking and spalling, instrumentation response, and falling-weight deflectometer data were monitored at select traffic intervals. 在重型车辆模拟器上使用双轮 P-8 测试装置进行测试。在选定的行车间隔时间内,对柔性路面车辙、刚性路面开裂和剥落、仪器响应以及落重挠度计数据进行了监测。 The results of the trafficking tests indicated that existing design predictions were generally overconservative. Thus, minimum pavement layer thickness recommendations were made to support a minimum level of contingency operations. 贩运测试结果表明,现有的设计预测普遍过于保守。因此,提出了最小路面层厚度建议,以支持最低水平的应急运行。 The results of full-scale flexible pavement experiment were utilized to support an analytical modeling effort to extend flexible pavement thickness recommendations beyond those evaluated. 利用全尺寸柔性路面实验结果来支持分析建模工作,以将柔性路面厚度建议扩展到评估范围之外。
DISCLAIMER: The contents of this report are not to be used for advertising, publication, or promotional purposes. Citation of trade names does not constitute an official endorsement or approval of the use of such commercial products. 免责声明:本报告内容不得用于广告、出版或促销目的。引用商品名称并不代表官方认可或批准使用此类商业产品。 All product names and trademarks cited are the property of their respective owners. The findings of this report are not to be construed as an official Department of the Army position unless so designated by other authorized documents. 所有引用的产品名称和商标均为其各自所有者的财产。除非有其他授权文件指定,否则本报告的结论不得解释为陆军部的官方立场。
Figure 1. Plan view of P-8 runway construction criteria test section … 3 图 1.P-8 跑道施工标准测试部分平面图...... 3
Figure 2. Profile view of P-8 construction criteria test lanes. … 4 图 2.P-8 施工标准测试车道剖面图。... 4
Figure 3. Clay subgrade moisture/density relationship … 8 图 3.粘土路基湿度/密度关系...... 8
Figure 4. Clay subgrade California bearing ratio (CBR)/moisture content relationship … 8 图 4.粘土路基加州承载比 (CBR) 与含水量的关系 ... 8
Figure 5. Base course aggregates … 9 图 5.基层集料...... 9
Figure 6. Limestone aggregate particle-size analysis … 10 图 6.石灰石骨料粒度分析...... 10
Figure 7. Limestone aggregate moisture/density relationship. … 10 图 7.石灰石骨料湿度/密度关系。... 10
Figure 8. Crushed gravel base particle-size analysis. … 11 图 8.碎石基层粒度分析。... 11
Figure 9. Crushed gravel base moisture/density relationship … 12 图 9.碎石基层湿度/密度关系...... 12
Figure 10. Test section excavation and preparation … 15 图 10.试验段的挖掘和准备 ... 15
Figure 11. Mixing and processing equipment. … 16 图 11.混合和加工设备。... 16
Figure 12. Material placement equipment. … 17 图 12.材料放置设备。... 17
Figure 13. Plan view of typical PCC instrumentation layout. … 18 图 13.典型 PCC 仪表布局平面图。... 18
Figure 14. Profile view of typical PCC instrumentation layout. … 18 图 14.典型 PCC 仪表布局剖面图。... 18
Figure 15. Plan view of typical HMA instrumentation layout. … 19 图 15.典型 HMA 仪表布局平面图。... 19
Figure 16. Profile view of typical HMA instrumentation layout … 19 图 16.典型 HMA 仪表布局剖面图 ... 19
Figure 17. EPC installation technique … 20 图 17.EPC 安装技术...... 20
Figure 18. Embedded concrete strain gauge installation … 21 图 18.嵌入式混凝土应变计安装 ... 21
Figure 19. SDD schematic … 23 图 19.SDD 原理图 ... 23
Figure 20. Single-depth deflectometer installation. … 24 图 20.单深度偏转仪安装。... 24
Figure 21. ASG installation. … 25 图 21.ASG 安装。... 25
Figure 22. ERDC Heavy Vehicle Simulator (HVS-A). … 29 图 22.ERDC 重型车辆模拟器 (HVS-A)。... 29
Figure 23. P-8 gear on HVS. … 30 图 23.HVS 上的 P-8 齿轮。... 30
Figure 24. Tire imprint of the P-8 test gear. … 31 图 24.P-8 试验齿轮的轮胎印。... 31
Figure 25. Bidirectional normally distributed wander pattern. … 32 图 25.双向正态分布的游走模式... 32
Figure 26. Example of HVS traffic wander methodology … 33 图 26.HVS 流量漫游方法示例...... 33
Figure 27. Pretraffic HWD results (8 in. thick PCC). … 36 图 27.交通前 HWD 结果(8 英寸厚 PCC)。... 36
Figure 28. Posttraffic HWD results (8 in. thick PCC) … 37 图 28.行车后 HWD 结果(8 英寸厚 PCC)...... 37
Figure 29. Crack map at 500 passes … 38 图 29.500 次通过时的裂缝图...... 38
Figure 30. Crack map at 546 passes … 39 图 30.546 个通道的裂缝图...... 39
Figure 31. Crack map at 750 passes. … 39 图 31.750 通过点的裂缝图。... 39
Figure 32. Crack map at 2,000 passes. … 39 图 32.2,000 通过点的裂缝图。... 39
Figure 33. Crack map at 3,000 passes. … 39 图 33.3,000 通过点的裂缝图。... 39
Figure 34. Crack map at 7,500 passes. … 40 图 34.7500 米处的裂缝图。... 40
Figure 35. Crack map at 10,000 passes. … 40 图 35.10,000 通过点的裂缝图。... 40
Figure 36. Crack map at 15,000 passes … 40 图 36.15,000 通过点的裂缝图...... 40
Figure 37. Total crack length with traffic (8 in. thick PCC). … 41 图 37.交通情况下的总裂缝长度(8 英寸厚 PCC)。... 41
Figure 38. ISM with traffic at various locations (8 in. thick PCC) … 43 图 38.不同位置的交通 ISM(8 英寸厚 PCC)............43
Figure 39. JE with traffic for dowelled and nondowelled joints (8 in. thick PCC) … 43 图 39.打钉和不打钉接缝的 JE(8 英寸厚 PCC).............43
Figure 40. Subgrade pressure response with traffic (8 in. thick PCC), … 45 图 40.交通对路基压力的响应(8 英寸厚 PCC)...... 45
Figure 41. SSG response of nondowelled joint (8 in. thick PCC). … 46 图 41.无冲洗接头(8 英寸厚 PCC)的 SSG 响应。... 46
Figure 42. SSG response of dowelled joint (8 in. thick PCC) … 46 图 42.锚固接头的 SSG 响应(8 英寸厚 PCC)...... 46
Figure 43. SSG response of midslab (8 in. thick PCC). … 47 图 43.中层板(8 英寸厚 PCC)的 SSG 响应。... 47
Figure 44. ESG response of nondowelled joint (8 in. thick PCC). … 48 图 44.无冲洗接头的 ESG 响应(8 英寸厚 PCC)。... 48
Figure 45. ESG response of dowelled joint (8 in. thick PCC) … 48 图 45.锚固连接的 ESG 响应(8 英寸厚 PCC)...... 48
Figure 46. ESG response of midslab (8 in. thick PCC). … 49 图 46.中层板(8 英寸厚 PCC)的 ESG 响应。... 49
Figure 47. Pretraffic HWD results (11 in. thick PCC) … 50 图 47.交通前 HWD 结果(11 英寸厚 PCC)...... 50
Figure 48. Posttraffic HWD results (11 in. thick PCC) … 51 图 48.交通后 HWD 结果(11 英寸厚 PCC)...... 51
Figure 49. ISM with traffic at various locations (11 in. thick PCC). … 53 图 49.不同位置的 ISM 流量(11 英寸厚 PCC)。... 53
Figure 50. JE with traffic for dowelled and nondowelled joints (11 in. thick PCC) … 53 图 50.打钉接缝和不打钉接缝的 JE 随车流变化情况(11 英寸厚 PCC)...... 53
Figure 51. Subgrade pressure response with traffic (11 in. thick PCC), … 54 图 51.交通情况下的路基压力响应(11 英寸厚 PCC)...... 54
Figure 52. SSG response of nondowelled joint (11 in. thick PCC) … 55 图 52.无冲洗接头的 SSG 响应(11 英寸厚 PCC)............55
Figure 53. SSG response of dowelled joint (11 in. thick PCC). … 56 图 53.螺纹连接的 SSG 响应(11 英寸厚 PCC)。... 56
Figure 54. SSG response of midslab (11 in. thick PCC). … 56 图 54.中层板(11 英寸厚 PCC)的 SSG 响应。... 56
Figure 55. ESG response of dowelled joint (11 in. thick PCC). … 57 图 55.锚固连接的 ESG 响应(11 英寸厚 PCC)。... 57
Figure 56. ESG response of midslab (11 in. thick PCC). … 58 图 56.中层板(11 英寸厚 PCC)的 ESG 响应。... 58
Figure 57. Example of rut-depth and permanent-deformation measurement. … 59 图 57.车辙深度和永久变形测量示例。... 59
Figure 58. Rut-depth progression with traffic … 61 图 58.车流的车辙深度变化...... 61
Figure 59. ISM with traffic. … 63 图 59.有流量的 ISM。... 63
Figure 60. Measured subgrade pressure response with traffic … 64 图 60.测量到的路基压力随交通量的变化...... 64
Figure 61. Subgrade pressure-effect of HMA thickness for LS base, 6 CBR subgrade. … 65 图 61.LS 基层、6 CBR 基层的 HMA 厚度对基层压力的影响。... 65
Figure 62. Subgrade pressure-effect of HMA thickness for LS base, 10 CBR subgrade. … 66 图 62.LS 基层、10 CBR 基层的 HMA 厚度对基层压力的影响。... 66
Figure 63. Subgrade pressure-effect of subgrade CBR for 4 in. HMA, LS base. … 66 图 63.4 英寸 HMA、LS 基层的基层压力对基层 CBR 的影响。... 66
Figure 64. Subgrade pressure-effect of subgrade CBR for 2 in . HMA, LS base … 67 图 64.2 英寸 HMA、LS 基层的基层压力对基层 CBR 的影响...... 67
Figure 65. Measured top-of-base pressure response with traffic. … 69 图 65.测量到的基底顶部压力随交通量的变化情况。... 69
Figure 66. Top-of-base pressure-effect of HMA thickness for LS base, 6 CBR subgrade. … 70 图 66.LS 基底、6 CBR 基层的基底压力对 HMA 厚度的影响。... 70
Figure 67. Top-of-base pressure-effect of HMA thickness for LS base, 10 CBR subgrade. … 71 图 67.LS 基底、10 CBR 基层的基底压力对 HMA 厚度的影响。... 71
Figure 68. Top-of-base pressure-effect of subgrade CBR for 4 in . HMA, LS base. … 71 图 68.4 英寸 HMA、LS 基底的基底压力对基底 CBR 的影响。... 71
Figure 69. Top-of-base pressure-effect of subgrade CBR for 2 in . HMA, LS base. … 72 图 69.2 英寸 HMA、LS 基底的基底压力对基底 CBR 的影响。... 72
Figure 70. Measured middepth base pressure response with traffic. … 74 图 70.交通情况下测量的中深度基底压力响应。... 74
Figure 71. Middepth base pressure-effect of HMA thickness for LS base, 6 CBR subgrade. … 75 图 71.LS 基底、6 CBR 基层的中深基面压力对 HMA 厚度的影响。... 75
Figure 72. Middepth base pressure-effect of HMA thickness for LS base, 10 CBR subgrade.75 图 72.LS 基底、10 CBR 基层的中深基面压力对 HMA 厚度的影响75。
Figure 73. Middepth base pressure-effect of subgrade CBR for 4 in. HMA, LS base. … 76 图 73.4 英寸 HMA、LS 基底的中深层基底压力对基底 CBR 的影响。... 76
Figure 74. Middepth base pressure-effect of subgrade CBR for 2 in. HMA, LS base. … 76 图 74.2 英寸 HMA、LS 基底的中深层基底压力对基底 CBR 的影响。... 76
Figure 75. Dynamic subgrade deflection with traffic. … 79 图 75.交通情况下的动态路基挠度... 79
Figure 76. Dynamic deflection-effect of HMA thickness for LS base, 6 CBR subgrade. … 79 图 76.LS 基底、6 CBR 基层的动态挠度对 HMA 厚度的影响。... 79
Figure 77. Dynamic deflection-effect of HMA thickness for LS base, 10 CBR subgrade. … 80 图 77.LS 基底、10 CBR 基层的动态挠度对 HMA 厚度的影响。... 80
Figure 78. Dynamic deflection-effect of subgrade CBR for 4 in. HMA, LS base. … 80 图 78.4 英寸 HMA、LS 基层的动态挠度对基层 CBR 的影响。... 80
Figure 79. Dynamic deflection-effect of subgrade CBR for 2 in . HMA, LS base. … 81 图 79.2 英寸 HMA、LS 基层的动态挠度对基层 CBR 的影响。... 81
Figure 80. Permanent subgrade deflection with traffic. … 83 图 80.交通量导致的路基永久变形... 83
Figure 81. Permanent deflection-effect of HMA thickness for LS base, 6 CBR subgrade. … 84 图 81.LS 基底、6 CBR 基层的永久挠度对 HMA 厚度的影响。... 84
Figure 82. Permanent deflection-effect of HMA thickness for LS base, 10 CBR subgrade. … 84 图 82.LS 基底、10 CBR 基层的永久挠度对 HMA 厚度的影响。... 84
Figure 83. Permanent deflection-effect of subgrade CBR for 4 in. HMA, LS base. … 85 图 83.4 英寸 HMA、LS 基层的永久挠度对基层 CBR 的影响。... 85
Figure 84. Permanent deflection-effect of subgrade CBR for 2 in. HMA, LS base. … 85 图 84.2 英寸 HMA、LS 基层的永久挠度对基层 CBR 的影响。... 85
Figure 85. Longitudinal ASG response with traffic … 88 图 85.纵向 ASG 响应与交通...... 88
Figure 86. Longitudinal strain-effect of HMA thickness for LS base, 10 CBR subgrade. … 89 图 86.LS 基底、10 CBR 基层的纵向应变对 HMA 厚度的影响。... 89
Figure 87. Longitudinal strain-effect of subgrade CBR for 2 in. HMA, LS base. … 89 图 87.2 英寸 HMA、LS 基层的纵向应变对基层 CBR 的影响。... 89
Figure 88. Transverse ASG response with traffic. … 92 图 88.横向 ASG 流量响应。... 92
Figure 89. Transverse strain-effect of HMA thickness for LS base, 6 CBR subgrade. … 92 图 89.LS 基层、6 CBR 基层的横向应变对 HMA 厚度的影响。... 92
Figure 90. Transverse strain-effect of HMA thickness for LS base, 10 CBR subgrade. … 93 图 90.LS 基底、10 CBR 基层的横向应变对 HMA 厚度的影响。... 93
Figure 91. Transverse strain-effect of subgrade CBR for 4 in. HMA, LS base … 93 图 91.4 英寸 HMA、LS 基层的横向应变对基层 CBR 的影响...... 93
Figure 92. Transverse strain-effect of subgrade CBR for 2 in. HMA, LS base … 94 图 92.2 英寸 HMA、LS 基层的横向应变对基层 CBR 的影响...... 94
Figure 93. Permanent deformation of geosynthetic reinforced sand with FRP. … 98 图 93.含玻璃钢的土工合成材料加固砂的永久变形。... 98
Figure 94. Photographs of geogrid stabilized backfill-posttraffic. … 98 图 94.土工格栅加固后回填土的照片。... 98
Figure 95. Permanent deformation of crushed limestone backfill with FRP. … 99 图 95.含玻璃钢的碎石灰石回填土的永久变形。... 99
Figure 96. Photographs of posttest limestone backfill. … 100 图 96.测试后石灰岩回填土的照片。... 100
Figure 97. Permanent deformation of cement stabilized sand with FRP. … 101 图 97.含玻璃钢的水泥稳定砂的永久变形。... 101
Figure 98. Photographs of posttest cement stabilized backfill. … 102 图 98.测试后水泥稳定回填土的照片。... 102
Figure 99. Spalling in stone and grout repair. … 104 图 99:石材剥落和灌浆修复。... 104
Figure 100. Processing debris backfill. … 105 图 100.处理碎片回填。... 105
Figure 101. Backfill placement process. … 106 图 101.回填安置过程。... 106
Figure 102. CSA placement process. … 108 图 102.CSA 安置流程。... 108
Figure 103. Permanent deformation of CSA crater repair. … 109 图 103.CSA 凹坑修复的永久变形。... 109
Figure 104. Joint spalling of CSA repair … 109 图 104.CSA 修补接缝剥落...... 109
Figure 105. ISM for CSA crater repair. … 110 图 105.用于 CSA 凹坑修复的 ISM。... 110
Figure 106. Placement of rapid-setting flowable fill/concrete cap. … 112 图 106.放置速凝可流动填料/混凝土盖。... 112
Figure 107. Joint spalling at 3,500 passes on rapid-setting (RS) crater repair … 113 图 107.快速固化 (RS) 凹坑修补 3 500 次后的接缝剥落............ 113
Figure 108. ISM for rapid-setting concrete crater repair. … 113 图 108.用于快速凝固混凝土坑洞修补的 ISM。... 113
Figure 109. Posttraffic layer deformation for 4 in. HMA, GR, 10 CBR … 115 图 109.4 英寸 HMA、GR、10 CBR 的交通后层变形...... 115
Figure 110. Posttraffic layer deformation for 2 in. HMA, GR, 10 CBR … 116 图 110.2 英寸 HMA、GR、10 CBR 的交通后层变形...... 116
Figure 111. Posttraffic layer deformation for 4 in. HMA, LS, 10 CBR. … 116 图 111.4 英寸 HMA、LS、10 CBR 的交通后层变形。... 116
Figure 112. Posttraffic layer deformation for 2 in . HMA, LS, 10 CBR. … 117 图 112.2 英寸 HMA、LS、10 CBR 的交通后层变形。... 117
Figure 113. Posttraffic layer deformation for 4 in. HMA, LS, 6 CBR. … 117 图 113.4 英寸 HMA、LS、6 CBR 的交通后层变形。... 117
Figure 114. Posttraffic layer deformation for 2HMA, LS, 6 CBR … 118 图 114.2HMA、LS 和 6 CBR 的交通后层变形...... 118
Figure 115. Photographs of excavated cross sections. … 119 图 115.挖掘横截面照片。... 119
Figure 116. Sublayering approach for decomposing the pavement structure with predefined analysis depths. … 124 图 116.以预定分析深度分解路面结构的分层方法。... 124
Figure 117. Use of transverse analysis points across width of test section to accumulate permanent deformation during each vehicle pass with wander. … 128 图 117.使用横向分析点横跨试验段宽度,累计车辆每次通过时的永久变形。... 128
Figure 118. Screenshot of PD model user interface, with plotted rut-depth history and computed pass level for a modified 2.25 in . rut-depth criteria … 129 图 118.PD 模型用户界面截图,图中绘制了车辙深度历史记录,并计算了修改后的 2.25 英寸车辙深度标准的通过水平...... 129
Figure 119. Approximation of nonuniform contact pressure of P-8 tire using the proposed method based on inverse analysis. … 132 图 119.使用基于反分析的拟议方法对 P-8 轮胎的非均匀接触压力进行近似计算。... 132
Figure 120. Comparison of rut-depth history between model and full-scale test items. … 133 图 120.模型和全尺寸测试项目的车辙深度历史对比。... 133
Figure 121. Comparison between predicted and measured vertical stress at the top of base. … 134 图 121.基底顶部预测垂直应力与实测垂直应力的比较。... 134
Figure 122. Comparison between predicted and measured vertical stress at middepth of base. … 135 图 122.基底中间深度处预测垂直应力与测量垂直应力的比较。... 135
Figure 123. Comparison between predicted and measured vertical stress at top of the subgrade … 136 图 123.路基顶部预测垂直应力与实测垂直应力的比较............ 136
Figure 124. Comparison between model predictions and ISM histories … 137 图 124.模型预测与 ISM 历史记录的比较...... 137
Figure 125. P-8 design curves for 2 in. thick HMA … 140 图 125.2 英寸厚 HMA 的 P-8 设计曲线...... 140
Figure 126. P-8 design curves for 4 in. thick HMA … 141 图 126.4 英寸厚 HMA 的 P-8 设计曲线...... 141
Figure 127. P-8 design curves for 6 in. thick HMA. … 142 图 127.6 英寸厚 HMA 的 P-8 设计曲线。... 142
Figure 128. Results of APT experiment in relation to design curves … 144 图 128.
Figure 129. Impact of varying HMA thickness on selected base course thickness. … 145 图 129.不同 HMA 厚度对所选基层厚度的影响。... 145
Figure 130. Minimum rigid pavement layer thickness for contingency operations. … 147 图 130.应急行动的最小刚性路面层厚度。... 147
Figure 131. Minimum flexible pavement layer thickness for contingency operations … 149 图 131.应急行动的最小柔性路面层厚度...... 149
Tables 表格
Table 1. ADR technology combinations. … 6 表 1.ADR 技术组合。... 6
Table 2. Hot-mix asphalt design properties. … 13 表 2.热拌沥青的设计特性... 13
Table 3. Portland cement concrete mixture properties … 14 表 3.波特兰水泥混凝土混合物性能 ... 14
Table 4. Rigid pavement as-built properties. … 27 表 4.刚性路面的竣工特性。... 27
Table 5. Flexible pavement as-built properties. … 28 表 5.柔性路面竣工属性。... 28
Table 6. Results of fresh PCC field tests. … 28 表 6.新鲜 PCC 现场测试结果。... 28
Table 7. Measurements from digitized tire imprints … 31 表 7.数字化轮胎印记的测量结果...... 31
Table 8. HWD joint load transfer efficiency results (8 in. thick PCC) … 37 表 8.HWD 接头荷载传递效率结果(8 英寸厚 PCC)...... 37
Table 9. Selected failure pass level for 8 in. thick PCC. … 41 表 9.8 英寸厚 PCC 的选定失效合格等级。... 41
Table 10. HWD joint load transfer efficiency results (11 in. thick PCC). … 51 表 10.HWD 接头荷载传递效率结果(11 英寸厚 PCC)。... 51
Table 11. Passes required to produce various rut depths … 61 表 11.产生不同车辙深度所需的通过次数...... 61
Table 12. Statistical analysis of subgrade pressure response … 68 表 12.
Table 13. Statistical analysis of top of base pressure response. … 73 表 13.底座顶部压力响应的统计分析。... 73
Table 14. Statistical comparison of middepth pressure response … 77 表 14.
Table 15. Statistical comparison of dynamic subgrade deflection response … 82 表 15.路基动态挠度响应的统计比较...... 82
Table 16. Statistical comparison of permanent subgrade deflection. … 87 表 16.永久性路基挠度的统计比较... 87
Table 17. Statistical comparison of longitudinal ASG response … 91 表 17.纵向 ASG 响应的统计比较...... 91
Table 18. Statistical comparison of transverse ASG response … 95 表 18.横向 ASG 响应的统计比较...... 95
Table 19. Geosynthetic properties. … 97 表 19.土工合成材料特性... 97
Table 20. Individual layer deformation … 115 表 20.单层变形...... 115
Table 21. Posttraffic material properties. … 120 表 21.交通后材料特性。... 120
Table 22. Change in material properties (posttraffic minus as-built). … 121 表 22.材料特性的变化(交通流量后减去竣工后) .... 121
Table 23. Comparison of PCASE7 (Beta-Alpha hybrid) predicted passes to failure and actual passes to failure … 123 表 23.PCASE7 (β-阿尔法混合)预测故障通过率与实际故障通过率的比较............. 123
Table 24. Comparison of PCASE7 (Alpha criteria) predicted passes to failure and actual passes to failure. … 123 表 24.PCASE7 (阿尔法标准)预测故障通过率与实际故障通过率的比较。... 123
Table 25. Calibrated parameters used in PD model for simulations against full- scale test data. … 138 表 25.根据全比例试验数据模拟 PD 模型时使用的校准参数。... 138
Table 26. ADR passes to failure. … 150 表 26.ADR 故障通过率。... 150
Table A-1. Pretest HWD data. … 154 表 A-1.预试验 HWD 数据。... 154
Table A-2. Posttest HWD data … 155 表 A-2.
Table A-3. Total crack length with passes. … 156 表 A-3.裂缝总长度与遍数... 156
Table A-4. FWD data at pass 0 … 156 表 A-4.0 号通道的 FWD 数据 ... 156
Table A-5. FWD data at pass 1 … 156 表 A-5.第 1 道工序的 FWD 数据 ... 156
Table A-6. FWD data at pass 10 … 157 表 A-6.第 10 道口的 FWD 数据...... 157
Table A-7. FWD data at pass 30. … 157 表 A-7.第 30 个关口的 FWD 数据。... 157
Table A-8. FWD data at pass 50. … 157 表 A-8.第 50 道口的 FWD 数据。... 157
Table A-9. FWD data at pass 75. … 158 表 A-9.第 75 道口的 FWD 数据。... 158
Table A-10. FWD data at pass 100. … 158 表 A-10.通过 100 时的 FWD 数据。... 158
Table A-11. FWD data at pass 300 … 158 表 A-11.通过 300 时的 FWD 数据...... 158
Table A-12. FWD data at pass 500 … 159 表 A-12.通过 500 时的 FWD 数据...... 159
Table A-13. FWD data at pass 750 … 159 表 A-13.750 道口的 FWD 数据...... 159
Table A-14. FWD data at pass 1,000. … 159 表 A-14.1,000 次通过时的 FWD 数据。... 159
Table A-15. FWD data at 3,000 passes. … 160 表 A-15.3,000 次通过时的 FWD 数据。... 160
Table A-16. FWD data at 5,000 passes. … 160 表 A-16.5000 次通过时的 FWD 数据。... 160
Table A-17. FWD data at pass 7,500 … 160 表 A-17.第 7,500 道口的 FWD 数据...... 160
Table A-18. FWD data at pass 10,000 … 161 表 A-18.10 000 次通过时的 FWD 数据...... 161
Table A-19. FWD data at pass 15,000 … 161 表 A-19.15000 次通过时的 FWD 数据...... 161
Table A-20. Earth pressure cell response data … 162 表 A-20.地压单元响应数据...... 162
Table A-21. SSG response data. … 162 表 A-21.SSG 响应数据。... 162
Table A-22. ESG response data. … 163 表 A-22.ESG 答复数据。... 163
Table B-1. HWD pretest data. … 164 表 B-1.HWD 预试验数据。... 164
Table B-2. HWD pretest data. … 165 表 B-2.HWD 预试验数据。... 165
Table B-3. FWD data at pass 0 … 166 表 B-3.0 号通道的 FWD 数据 ... 166
Table B-4. FWD data at pass 10 . … 166 表 B-4.第 10 道口的 FWD 数据 .... 166
Table B-5. FWD data at pass 50 … 166 表 B-5.通过 50 时的 FWD 数据 ... 166
Table B-6. FWD data at pass 100 … 167 表 B-6.通过 100 时的 FWD 数据 ... 167
Table B-7. FWD data at pass 300 . … 167 表 B-7.通过 300 时的 FWD 数据 .... 167
Table B-8. FWD data at pass 500 … 167 表 B-8.通过 500 时的 FWD 数据...... 167
Table B-9. FWD data at pass 1,000 . … 168 表 B-9.1,000 次通过时的 FWD 数据 .... 168
Table B-10. FWD data at pass 1,500 … 168 表 B-10.第 1 500 道口的 FWD 数据...... 168
Table B-11. FWD data at pass 3,000 … 168 表 B-11.第 3 000 道口的 FWD 数据...... 168
Table B-12. FWD data at pass 5,000 … 169 表 B-12.第 5000 道口的 FWD 数据...... 169
Table B-13. FWD data at pass 7,500 . … 169 表 B-13.第 7,500 道口的 FWD 数据 .... 169
Table B-14. FWD data at pass 10,000 … 169 表 B-14.10 000 次通过时的 FWD 数据...... 169
Table B-15. FWD data at pass 15,000 … 170 表 B-15.15,000 及格点的 FWD 数据...... 170
Table B-16. FWD data at pass 20,000 … 170 表 B-16.20 000 次通过时的 FWD 数据...... 170
Table B-17. FWD data at pass 30,000 … 170 表 B-17.30 000 次关口的 FWD 数据...... 170
Table B-18. FWD data at pass 40,000 … 171 表 B-18.通过 40,000 点时的 FWD 数据...... 171
Table B-19. FWD data at pass 50,000 … 171 表 B-19.通过 50 000 次时的 FWD 数据...... 171
Table B-20. Earth pressure cell response data. … 172 表 B-20.地压单元响应数据。... 172
Table C-1. Rut-depth data. … 173 表 C-1.Rut-depth 数据。... 173
Table C-2. ISM data. … 174 表 C-2.ISM 数据。... 174
Table C-3. Subgrade pressure cell response data. … 175 表 C-3.基层压力单元响应数据。... 175
Table C-4. Top of base pressure cell response data … 177 表 C-4.
Table C-5. Middepth of base pressure cell response data … 179 表 C-5.
Table C-6. Dynamic single-depth deflectometer response data … 181 表 C-6.
Table C-7. Permanent single-depth deflectometer response data. … 183 表 C-7.永久性单深度偏转仪响应数据。... 183
Table C-8. Longitudinal ASG response data … 185 表 C-8.纵向 ASG 响应数据...... 185
Table C-9. Transverse ASG response data. … 187 表 C-9.横向 ASG 响应数据。... 187
Preface 序言
This study was conducted for the Naval Facilities Engineering and Expeditionary Warfare Center (NAVFAC EXWC) and the Naval Expeditionary Combat Command under Project No. 488187, Funding Account Code B36399. Mr. Michael L. 这项研究是为海军设施工程和远征作战中心(NAVFAC EXWC)和海军远征作战司令部进行的,项目编号为 488187,资金账户代码为 B36399。Mr. Ringen, NAVFAC, provided technical guidance and review during the project. Mr. Scott Barradas, NAVFAC, provided program oversight. Mr. Jeb S. 美国海军陆战队司令部的 Ringen 在项目期间提供了技术指导和审查。NAVFAC 的 Scott Barradas 先生负责项目监督。Mr. Tingle, senior scientific technical manager, Geotechnical and Structures Laboratory (GSL), US Army Engineer Research and Development Center (ERDC), was the ERDC program manager. 美国陆军工程研发中心(ERDC)岩土工程和结构实验室(GSL)高级科学技术经理 Tingle 是 ERDC 的项目经理。
The work was performed by the Airfields and Pavements Branch (GMA) of the Engineering Systems Division (GM), ERDC-GSL. At the time of publication, Ms. Anna M. Jordan was chief, GMA; Mr. Justin S. 这项工作由 ERDC-GSL 工程系统部 (GM) 的机场和路面处 (GMA) 负责。出版时,安娜-M-乔丹(Anna M. Jordan)女士任 GMA 处处长;贾斯汀-S. Strickler was chief, GM; and Mr. Nicholas Boone was the technical director for Force Projection and Maneuver Support. The deputy director of ERDC-GSL was Mr. Charles W. Ertle II, and the director was Mr. Bartley P. Durst. 斯特里克勒是全球机制的负责人;尼古拉斯-布恩先生是兵力投射和机动支持的技术主管。ERDC-GSL 的副主任是 Charles W. Ertle II 先生,主任是 Bartley P. Durst 先生。
COL Christian Patterson was the commander of ERDC, and Dr. David W. Pittman was the director. 克里斯蒂安-帕特森(Christian Patterson)上校是 ERDC 的指挥官,戴维-W-皮特曼(David W. Pittman)博士是主任。
1 Introduction 1 引言
1.1 Background 1.1 背景
The P-8 Poseidon aircraft presents a unique structural challenge for military airfield pavements. P-8 海神飞机对军用机场路面的结构提出了独特的挑战。 Reported increases in load-related distresses from P-8 trafficking are likely due to greater gear loads compared to fighter aircraft coupled with greater tire pressures compared to cargo aircraft. 据报告,P-8 运输过程中与载荷相关的损伤增加,可能是由于与战斗机相比,齿轮载荷更大,与货机相比,轮胎压力更大。 The close spacing of the dual-tire gear configuration has also been damaging to pavement joints. In addition, airfield damage repair (ADR) technologies have not been validated for the P-8 loading; thus, their performance under P-8 loading conditions is unknown. 双轮胎齿轮配置的间距过近也会对路面接缝造成损害。此外,机场损伤修复 (ADR) 技术尚未针对 P-8 负载进行验证,因此其在 P-8 负载条件下的性能尚不清楚。 Currently, UFC 3-260-02 (USACE 2001) outlines performance criteria for conventional flexible and rigid airfield pavements based on the California bearing ratio (CBR) vertical stress-based methodology and Westergaard’s thin plate theory, respectively. 目前,UFC 3-260-02(美国陆军工程兵部队,2001 年)分别根据基于垂直应力的加利福尼亚承载比 (CBR) 方法和 Westergaard 的薄板理论,概述了传统柔性和刚性机场路面的性能标准。 There are also performance criteria established for these pavement systems using layered elastic analysis. These performance criteria were based upon diverse military aircraft systems with significantly different loading conditions, and their applicability to the P-8\mathrm{P}-8 's military gear configuration is uncertain. In addition, conventional airfield pavement design criteria are based upon the design of enduring pavement systems sustaining many aircraft operations over a lengthy service life. 此外,还利用分层弹性分析为这些路面系统制定了性能标准。这些性能标准是根据不同的军用飞机系统制定的,这些系统的负载条件有很大的不同,它们是否适用于 P-8\mathrm{P}-8 的军用装备配置还不确定。此外,传统的机场路面设计标准是基于耐用路面系统的设计,这些路面系统可在较长的使用寿命内维持多架飞机的运行。 Furthermore, there is currently no formal performance model established for anything related to airfield crater repairs except for the airfield matting distress model outlined in reports such as MP-4-29 (Foster and Burns 1952), TR No. 此外,除了 MP-4-29(Foster 和 Burns,1952 年)、TR No. 3-539 (Thompson and Burns 1960) and the semi-prepared runway criteria discussed in TR S-70-5 (Hammitt and Aspinall 1970). Current ADR performance criteria is based upon empirical testing to meet minimum mission requirements. 3-539(Thompson 和 Burns,1960 年)以及 TR S-70-5(Hammitt 和 Aspinall,1970 年)中讨论的半预制跑道标准。目前的 ADR 性能标准基于经验测试,以满足最低任务要求。 Consequently, there is a need to gather performance data in terms of simulated P-8 aircraft traffic over nonstandard expeditionary pavement structures and ADR sections. 因此,有必要收集模拟 P-8 飞机在非标准远征路面结构和 ADR 断面上飞行的性能数据。
1.2 Objective 1.2 目标
The objective of this research was to develop improved rigid and flexible pavement performance criteria for expeditionary operations of the fully loaded P-8 aircraft. 这项研究的目的是为满载的 P-8 飞机的远征作业制定改进的刚性和柔性路面性能标准。 These criteria were based on results from a full-scale instrumented test section trafficked by a simulated P-8 gear. 这些标准是根据模拟 P-8 齿轮所经过的全尺寸仪器测试路段的结果制定的。
There were two distinct components to the effort: (1) evaluation of the minimum structural pavement design required to support expeditionary operations and (2) evaluation of the compatibility/performance of P-8 operations on emerging ADR technologies. 这项工作有两个不同的组成部分:(1) 评估支持远征行动所需的最低结构路面设计;(2) 评估新兴 ADR 技术与 P-8 行动的兼容性/性能。
1.3 Scope 1.3 范围
The performance of relatively thin pavement structures and emerging ADR technologies were evaluated under simulated P-8 traffic. 在模拟 P-8 交通流量下,对相对较薄的路面结构和新兴 ADR 技术的性能进行了评估。 Full-scale instrumented pavement test sections were constructed to fully characterize the pavement structural support requirements for the P-8 aircraft. 为全面确定 P-8 飞机的路面结构支撑要求,建造了全尺寸仪器路面试验段。 The test program included two distinct evaluations: (1) the suitability of emerging ADR technologies for supporting P-8 aircraft operations and (2) the minimum structural requirements for designing, building, and operating expeditionary airfields to sustain a limited number of P-8\mathrm{P}-8 sorties. The full-scale instrumented pavement sections were designed with different layer thicknesses and surface types (flexible pavement and rigid pavement). 测试项目包括两个不同的评估:(1) 新兴 ADR 技术是否适合支持 P-8 飞机的运行;(2) 设计、建造和运行远征机场的最低结构要求,以维持有限的 P-8\mathrm{P}-8 架次。全尺寸仪器路面断面的设计采用了不同的层厚和表面类型(柔性路面和刚性路面)。
1.4 Approach 1.4 方法
The test sections were trafficked with the US Army Engineer Research and Development Center’s (ERDC’s) Heavy Vehicle Simulator (HVS) using authentically configured actual P-8 aircraft wheels loaded to simulate the maximum operational weight of the aircraft. 测试路段采用美国陆军工程研发中心(ERDC)的重型车辆模拟器(HVS),使用真实配置的实际 P-8 飞机机轮加载,以模拟飞机的最大运行重量。 The performance of the various expeditionary pavement sections was recorded and used to establish pass-to-failure performance data to validate or adjust the existing pavement performance curve as required. 对各种远征路面路段的性能进行了记录,并用于建立通过-失效性能数据,以验证或根据需要调整现有的路面性能曲线。 The performance in terms of passes to failure of the emerging ADR technologies was also recorded to verify the compatibility of these new expedient ADR solutions for use with the P-8\mathrm{P}-8 aircraft. In addition, pavement response data were collected from the pavement instrumentation to inform mechanistic pavement models suitable to adapt current pavement design and evaluation criteria for the P-8\mathrm{P}-8. Finally, the construction of the different full-scale pavement sections provided information regarding the constructability of these pavement features in expeditionary environments. 此外,还记录了新兴 ADR 技术从通过到失效的性能,以验证这些新的便捷 ADR 解决方案与 P-8\mathrm{P}-8 飞机的兼容性。此外,还从路面仪器中收集了路面响应数据,为机械路面模型提供信息,以适应 P-8\mathrm{P}-8 飞机当前的路面设计和评估标准。最后,不同全尺寸路面断面的施工提供了有关这些路面特征在远征环境中可施工性的信息。 These performance data can be used to mitigate risk by increasing confidence in the performance criteria while providing the Navy with options for expeditionary airfield designs for the P-8 that reduce construction costs. 这些性能数据可用于增强对性能标准的信心,从而降低风险,同时为海军提供可降低建造成本的 P-8 远征机场设计方案。 The results of the full-scale experimentation were used to draft new criteria documents for the construction of Navy expeditionary airfields. 全面试验的结果被用于起草海军远征机场建设的新标准文件。
2 Test Plan and Layout 2 测试计划和布局
A large, full-scale pavement test section was constructed under cover in Hangar 2 at ERDC. Construction under cover minimized the influence of soil moisture changes caused by variable weather conditions throughout the duration of the test. 在 ERDC 的 2 号机库中,在覆盖物下建造了一个大型全尺寸路面试验段。在整个试验期间,在覆盖物下施工最大程度地减少了多变天气条件造成的土壤湿度变化的影响。
The full-scale test sections were designed to accomplish the objectives of the test program given the constraints imposed by the available funding and schedule. Thus, a full matrix of independent variables was cost prohibitive and would have taken years to accomplish. 全尺寸试验段的设计是为了在现有资金和时间表的限制下实现试验计划的目标。因此,完整的自变量矩阵成本过高,需要数年才能完成。 The test sections were designed to provide the required information to evaluate existing performance models for the P-8, to provide enough performance data to modify the models for improved low-pass criteria if necessary, and to validate the performance compatibility of the P-8\mathrm{P}-8 with new expeditionary ADR technologies. 试验段的设计旨在提供评估 P-8 现有性能模型所需的信息,提供足够的性能数据以便在必要时修改模型以改进低通标准,并验证 P-8\mathrm{P}-8 与新的远征 ADR 技术在性能上的兼容性。
Figure 1 shows a plan view of the P-8 Runway Construction Criteria fullscale test section for rigid and flexible pavements. 图 1 显示了 P-8 跑道施工标准刚性和柔性路面全尺寸试验段的平面图。 This test section supported the evaluation of ADR technology compatibility with the P-8 and the evaluation of the minimum structural requirements for expeditionary runways supporting the P-8\mathrm{P}-8. Figure 2 shows a profile view outlining the structural layering of the individual test items. 该测试部分支持对 ADR 技术与 P-8 的兼容性进行评估,以及对支持 P-8\mathrm{P}-8 的远征跑道的最低结构要求进行评估。图 2 显示了各个测试项目的结构分层剖面图。
Figure 1. Plan view of P-8 runway construction criteria test section. 图 1.P-8 跑道施工标准试验段平面图。
Figure 2. Profile view of P-8 construction criteria test lanes. 图 2.P-8 施工标准测试车道剖面图。
2.1 Pavement Structural Requirements 2.1 路面结构要求
Figure 1 shows that test Lanes 1 and 2 each consisted of seven 20 ft by 20ft^(1)20 \mathrm{ft}^{1} slabs of PCC. Lane 1 was comprised of 14 in. thick PCC over a 6 in. thick crushed limestone subbase/working platform over a 10 CBR high-plasticity (CH) subgrade. 图 1 显示,测试车道 1 和 2 各由七块 20 英尺 x 20ft^(1)20 \mathrm{ft}^{1} 的 PCC 板组成。车道 1 由 14 英寸厚的 PCC 组成,上面是 6 英寸厚的碎石灰石基层/工作平台,上面是 CBR 值为 10 的高弹性 (CH) 基层。 Lane 1 served two purposes: (1) to provide an upper end performance point for PCC pavements (approximately 5,000-10,000 passes) and (2) to provide a location for evaluation of the Expedient and Expeditionary Airfield Damage Repair (E-ADR) technologies. 1 号车道有两个目的:(1) 为 PCC 路面提供一个上限性能点(约 5,000-10,000 次);(2) 为评估快速和远征机场损坏修复 (E-ADR) 技术提供一个地点。 Lane 2 consisted of two thickness of PCC (8 in. and 11 in.) placed over a 6 in. thick crushed limestone subbase/working platform over a 10 CBR CH subgrade. 2 号车道包括两层厚的水泥混凝土(8 英寸和 11 英寸),铺设在 6 英寸厚的碎石灰石基层/工作平台上,基层的 CBR 值为 10。 The purpose of Lane 2 was to provide P-8 performance data for relatively thin PCC slabs (designed for approximately 100-500 passes) and medium thicknesses of PCC (designed for approximately 750-3,000 passes). 巷道 2 的目的是为相对较薄的 PCC 板(设计通过次数约为 100-500 次)和中等厚度的 PCC(设计通过次数约为 750-3000 次)提供 P-8 性能数据。 Dowelbar assemblies were installed along one joint in each PCC test item to 在每个 PCC 测试项目的一个接缝处安装道钉杆组件,以便
investigate load transfer. The assemblies consisted of 1.25 in . diam epoxycoated dowel bars 18 in . long and spaced at 12 in. intervals. Lanes 3 and 4 were designed to collect P-8\mathrm{P}-8 performance data on relatively thin hot mix asphalt (HMA) flexible pavements. Lane 3 consisted of a 4 in. thick layer of HMA placed over 12 in . of a low-quality crushed gravel base over a 10 CBR CH subgrade. The same 4 in. thick HMA layer was placed over 12 in . 研究荷载传递。这些组件由直径为 1.25 英寸、长 18 英寸、间距为 12 英寸的环氧树脂涂层镙杆组成。第 3 和第 4 车道的设计目的是收集相对较薄的热拌沥青 (HMA) 柔性路面的 P-8\mathrm{P}-8 性能数据。第 3 车道由 4 英寸厚的 HMA 层组成,铺设在 12 英寸的低质碎石基层上,基层的 CBR 值为 10。同样 4 英寸厚的 HMA 层铺设在 12 英寸厚的 CBR CH 基层上。 of high-quality base material over two different CH subgrade strengths (6 and 10 CBR). Current Navy criteria allow 4 in. as the minimum HMA thickness for conventional airfield flexible pavements. Lane 4 consisted of the same pavement cross sections with only 2 in. 在两种不同的 CH 基层强度(6 CBR 和 10 CBR)上使用高质量的基层材料。海军现行标准允许传统机场柔性路面的最小 HMA 厚度为 4 英寸。第 4 车道由相同的路面横截面组成,厚度仅为 2 英寸。 of HMA as an absolute minimum design for limited traffic in an expeditionary environment. 将 HMA 作为远征环境中有限交通的绝对最低设计标准。 The inclusion of the lower-quality crushed gravel base provided pavement performance data for situations in which a quality base course meeting Navy standards was unavailable or where the airfield was previously built by other entities. 在没有符合海军标准的优质基层或机场以前由其他实体建造的情况下,加入低质量碎石基层可提供路面性能数据。 Flexible pavement designs are sensitive to subgrade strength; thus, the two subgrade strengths provided performance data for dissimilar site conditions allowing meaningful evaluation of current performance criteria. 柔性路面设计对基层强度非常敏感;因此,两种基层强度为不同的现场条件提供了性能数据,从而可以对当前的性能标准进行有意义的评估。
The test items contained a suite of instrumentation consisting of both rigid and flexible pavement strain gauges, earth pressure cells, single-depth deflectometers (SDD), moisture probes, pore-water pressure transducers, and temperature probes. 测试项目包含一套仪器,包括刚性和柔性路面应变仪、土压力传感器、单深度偏转仪 (SDD)、湿度探头、孔隙水压力传感器和温度探头。 Instrumentation is described in detail in Chapter 5. 第 5 章将详细介绍仪器设备。
Simulated aircraft traffic was applied using a dual-wheel P-8 tire configuration mounted on ERDC’s HVS. The dual-wheel gear configuration was loaded to a nominal total force of 89,000lbf89,000 \mathrm{lbf} that was verified prior to trafficking using a set of calibrated mobile aircraft scales. Tire pressures were maintained at 220 psi throughout testing and were monitored daily. Details regarding simulated aircraft traffic can be found in Chapter 7. 使用安装在 ERDC HVS 上的双轮 P-8 轮胎配置进行了模拟飞机运输。双轮齿轮配置被加载到 89,000lbf89,000 \mathrm{lbf} 的标称总力,并在运输前使用一套校准过的移动飞机秤进行验证。在整个测试过程中,轮胎压力保持在 220 psi,并每天进行监测。有关模拟飞机交通的详细信息,请参见第 7 章。
2.2 ADR Capabilities 2.2 ADR 功能
For the evaluation of ADR technologies, simulated “craters” were cut through the PCC surface in Lane 1. Each repair technology was constructed within a simulated crater, and the HVS was used to evaluate the performance of the repairs under simulated P-8 traffic. 为评估 ADR 技术,在 1 号车道的 PCC 表面开凿了模拟 "凹坑"。每种修复技术都在模拟坑内进行施工,并使用 HVS 评估修复在模拟 P-8 交通情况下的性能。 Table 1 outlines the repair technologies that were evaluated. 表 1 概述了所评估的维修技术。
A detailed analysis was conducted to evaluate the performance of the ADR technologies, rigid pavement test items, and flexible pavement items. The compatibility of emerging ADR methods with the P-8 aircraft was directly evaluated, and the number of P-8 passes that each method sustained prior to failure of the system was directly measured. 对 ADR 技术、刚性路面测试项目和柔性路面项目的性能进行了详细的分析评估。直接评估了新出现的 ADR 方法与 P-8 飞机的兼容性,并直接测量了每种方法在系统失效之前所能承受的 P-8 通过次数。 The pavement performance data were analyzed to determine the minimum PCC or HMA thickness necessary to support P-8 operations. 对路面性能数据进行分析,以确定支持 P-8 运营所需的最小 PCC 或 HMA 厚度。 Instrumentation response data (stress, strain, and deflection) were used to validate mechanistic pavement response models that allow the extension of the models to other pavement structures of interest. The instrumentation data were used to validate or modify pavement performance models by relating critical pavement response parameters (stress, strain, or deflection at critical locations) to the damage resulting from cumulative traffic passes. 仪器响应数据(应力、应变和挠度)用于验证机械路面响应模型,以便将模型扩展到其他相关路面结构。通过将关键路面响应参数(关键位置的应力、应变或挠度)与累积交通流量造成的损坏联系起来,仪器数据可用于验证或修改路面性能模型。 These data provided improved and validated models for extending pavement design and evaluation methods to low-volume airfield pavement structures. 这些数据为将路面设计和评估方法扩展到低容量机场路面结构提供了改进和验证模型。
Specifically, the following comparisons were made from this study: 具体来说,本研究进行了以下比较:
Comparison of passes to failure of emerging ADR methods 比较新出现的 ADR 方法的通过率和失败率
Effect of PCC thickness on passes to failure PCC 厚度对失效通过次数的影响
Effect of PCC thickness on measured instrumentation response PCC 厚度对测量仪器响应的影响
Effect of HMA thickness on passes to failure HMA 厚度对失效通过次数的影响
Effect of HMA thickness on measured instrumentation response HMA 厚度对测量仪器响应的影响
Effect of base course strength on passes to failure 基层强度对失效通过率的影响
Effect of base course strength on measured instrumentation response 基层强度对测量仪器响应的影响
Effect of subgrade CBR strength on passes to failure 路基 CBR 强度对失效通过次数的影响
Effect of subgrade CBR on measured instrumentation response 路基 CBR 对测量仪器响应的影响
Effect of gross load on pavement response. 总荷载对路面响应的影响
3 Materials 3 种材料
Laboratory tests were performed to characterize each component layer material as well as underlying subgrade soils. Material characterization test results are presented in the following paragraphs. 进行了实验室测试,以确定各组成层材料以及底层土壤的特征。材料特性测试结果见以下段落。
3.1 Subgrade 3.1 基层
The design subgrade soil consisted of a locally sourced CH, commonly referred to as Vicksburg buckshot. 设计的路基土壤由一种当地产的 CH 组成,通常被称为 Vicksburg buckshot。 This material has been used extensively in test section construction principally for its ability to maintain moisture content (and consequently design strength) over an extended time. A particle-size analysis indicated the material consisted of 96.8%96.8 \% fines passing the No. 200 sieve. The soil had a liquid limit (LL) of 85%85 \%, a plasticity limit (PL) of 29%29 \%, and a plasticity index (PI) of 56%56 \%, as determined by American Society for Testing and Materials (ASTM) D4318 (ASTM 2017c). 这种材料被广泛用于试验段施工,主要是因为它能够在较长时间内保持含水量(从而保持设计强度)。粒度分析表明,该材料由通过 200 号筛的 96.8%96.8 \% 细粒组成。根据美国材料与试验协会(ASTM)D4318(ASTM 2017c)的测定,该土壤的液限(LL)为 85%85 \% ,塑限(PL)为 29%29 \% ,塑性指数(PI)为 56%56 \% 。 According to the Unified Soil Classification System (USCS) (ASTM 2017a), the soil was classified as CH and an A-7-6 according to the American Association of State and Highway Transportation Officials (AASHTO) classification system (AASHTO 2012). 根据统一土壤分类系统(USCS)(ASTM 2017a),土壤被归类为 CH,根据美国州和公路交通官员协会(AASHTO)分类系统(AASHTO 2012),土壤被归类为 A-7-6。
Modified Proctor compaction tests (ASTM D1557 [2012]) were performed to determine the relationship between moisture content and dry density. The maximum dry density was found to be 106.1 pcf at an optimum moisture content of 17.5%17.5 \% (ASTM 2012). Graphical results of the moisture-density relationship test are shown in Figure 3. 为确定含水量与干密度之间的关系,进行了改良型 Proctor 压实试验(ASTM D1557 [2012])。在最佳含水量为 17.5%17.5 \% 时,最大干密度为 106.1 pcf(ASTM 2012)。湿度-密度关系测试的图表结果如图 3 所示。
To determine an in-place moisture content at the targeted 10 CBR and 6 CBR, a suite of ASTM D1883 laboratory CBR tests was performed (ASTM 2016). These tests were conducted at moisture contents ranging from approximately 20%20 \% to approximately 40%40 \%. Based on the relationship between moisture content and CBR, a target moisture content of 28%28 \% was selected to achieve a 10 CBR, and a target moisture content of 32%32 \% was selected to achieve a 6 CBR. The relationship between CBR and moisture content is presented graphically in Figure 4. 为确定目标 10 CBR 和 6 CBR 的就地含水量,进行了一系列 ASTM D1883 实验室 CBR 测试(ASTM 2016)。这些测试是在大约 20%20 \% 到大约 40%40 \% 的含水量范围内进行的。根据含水量与 CBR 之间的关系,选择 28%28 \% 的目标含水量以达到 10 CBR,选择 32%32 \% 的目标含水量以达到 6 CBR。CBR 与含水量之间的关系如图 4 所示。
Figure 4. Clay subgrade California bearing ratio (CBR)/moisture content relationship. 图 4.粘土路基加州承载比 (CBR) 与含水量的关系。
3.2 Base Course 3.2 基层
Crushed limestone (LS) and crushed gravel (GR) (Figure 5) were used to construct the flexible aggregate base courses, and LS was used to construct a working platform for concrete placement. 碎石灰岩(LS)和碎砾石(GR)(图 5)用于建造柔性骨料基层,LS 用于建造混凝土浇筑的工作平台。 LS was selected to represent a strong base (historically this material yields an in situ CBR of 100+) and the GR to represent a base material that may be substantially weaker yet representative of materials that could be encountered in pavement sections in less developed theaters of operation. 选择 LS 代表强基(历史上这种材料的原位 CBR 值在 100 以上),选择 GR 代表可能较弱的基底材料,但代表在欠发达作业区的路面路段可能遇到的材料。 Material characterization results are summarized in the following sections. 材料表征结果概述如下。
Figure 5. Base course aggregates. 图 5.基层集料。
(a) Crushed limestone base (a) 碎石石灰岩基础
(b) Crushed gravel base (b) 碎石路基
3.2.1 LS Base 3.2.1 LS 基础
The gradation for the LS base is shown in Figure 6. ASTM procedure D2487 was used to determine that the base course was comprised of 66.2%66.2 \% gravel, 25.3%25.3 \% sand, and 8.5%8.5 \% nonplastic fines passing the No. 200 sieve (ASTM 2017a). The coefficient of curvature ( C_(c)\mathrm{C}_{\mathrm{c}} ) was calculated as 7.63 , and the coefficient of uniformity ( (C_(u))\left(\mathrm{C}_{\mathrm{u}}\right) was 68.21 . The LS aggregate base was classified as a poorly graded gravel with silt and sand (GP-GM) according to the USCS (ASTM 2017a) and an A-1-a according to the AASHTO procedure (AASHTO 2012). LS 基层的级配如图 6 所示。采用 ASTM D2487 程序确定基层由 66.2%66.2 \% 碎石、 25.3%25.3 \% 砂和通过 200 号筛的 8.5%8.5 \% 非塑性细粒组成(ASTM 2017a)。经计算,曲率系数( C_(c)\mathrm{C}_{\mathrm{c}} )为 7.63,均匀系数( (C_(u))\left(\mathrm{C}_{\mathrm{u}}\right) )为 68.21。根据 USCS(ASTM 2017a),LS 集料基础被归类为含粉砂和砂的低级砾石(GP-GM),根据 AASHTO 程序(AASHTO 2012),LS 集料基础被归类为 A-1-a。 Modified Proctor compaction tests (Figure 7) were performed in accordance with ASTM D1557 Method C Modified (ASTM 2012). The maximum dry density was 147.9 pcf at an optimum moisture content of 5.2%5.2 \%. 根据 ASTM D1557 方法 C Modified(ASTM 2012)进行了改良型 Proctor 压实度测试(图 7)。在最佳含水量为 5.2%5.2 \% 时,最大干密度为 147.9 pcf。
The gradation for the crushed gravel is shown in Figure 8. The GR base course was comprised of 38%38 \% gravel, 58%58 \% sand, and 3.5%3.5 \% nonplastic fines passing the No. 200 sieve. The Cc was calculated as 1.51 , and the Cu was 10.56. The GR aggregate base was classified as a well-graded sand (SW) according to the USCS (ASTM 2017a) and an A-1-a according to the AASHTO procedure (AASHTO 2012). 碎石的级配如图 8 所示。GR 基层由 38%38 \% 碎石、 58%58 \% 砂和 3.5%3.5 \% 通过 200 号筛的非塑性细粒组成。经计算,Cc 为 1.51,Cu 为 10.56。根据 USCS(ASTM 2017a),GR 骨料基础被归类为级配良好的砂(SW),根据 AASHTO 程序(AASHTO 2012),GR 骨料基础被归类为 A-1-a。 Modified Proctor compaction tests (Figure 9) were performed in accordance with ASTM D1557 Method B Modified (ASTM 2012). The maximum dry density was 115.1 pcf at an optimum moisture content of 8.4%8.4 \%. 根据 ASTM D1557 方法 B Modified(ASTM 2012)进行了改良型 Proctor 压实度测试(图 9)。在最佳含水量为 8.4%8.4 \% 时,最大干密度为 115.1 pcf。
Figure 8. Crushed gravel base particle-size analysis. 图 8.碎石基层粒度分析。
Figure 9. Crushed gravel base moisture/density relationship. 图 9.碎石基层湿度/密度关系。
3.3 HMA
A 9.5 mm nominal maximum aggregate size (NMAS) HMA surface mixture was selected for placement of the wearing surface of the flexible test items. The HMA mixture was one that is representative of a typical airfield mix and consisted of 40%40 \% limestone aggregate, 59%59 \% gravel/sand, and 1%1 \% hydrated lime. Recycled asphalt pavement (RAP) was not allowed, and natural sand was limited to 15%15 \% of the total aggregate blend. 在铺设柔性测试项目的耐磨表面时,选择了公称最大骨料粒径为 9.5 毫米的 HMA 表面混合物。HMA 混合料是一种典型的机场混合料,由 40%40 \% 石灰石骨料、 59%59 \% 砾石/砂和 1%1 \% 熟石灰组成。不允许使用回收的沥青路面 (RAP),天然砂只限于总混合骨料中的 15%15 \% 。
Pertinent mixture properties are summarized in Table 2. 表 2 概述了混合物的相关特性。
3.4 PCC
A 5,000 psi design compressive strength PCC mixture was selected for placement of the surface of the rigid pavement test items. Additionally, the PCC mixture had a design flexural strength of 650 psi. 刚性路面测试项目的表面铺设选用了设计抗压强度为 5000 psi 的 PCC 混合物。此外,PCC 混合物的设计抗折强度为 650 psi。 Cementitious materials consisted of a Type 1 portland cement and a Class C fly ash. 胶凝材料包括 1 级波特兰水泥和 C 级粉煤灰。
Coarse aggregate consisted of an angular crushed limestone aggregate that was classified as a #57 stone (i.e., 1 in. maximum aggregate size.) 粗骨料由角状碎石灰石骨料组成,被归类为 57 号石料(即最大骨料尺寸为 1 英寸)。
Pertinent mixture properties are provided in Table 3. 表 3 列出了混合物的相关特性。
Material Type Description Design Quantity Specific Gravity Volume ( ft^(3) )
Cement Type 1 526 lb 3.15 2.68
Fly Ash Class C 132 lb 2.63 0.80
Coarse Aggregate #57 Limestone 1900 lb 2.69 11.32
Fine Aggregate Concrete Sand 1083 lb 2.64 6.57
Water Potable 32 gal. 1.00 4.28
Admixture Water Reducer 26 oz - -
Admixture Air Entraining 3 oz - -
Air Content 5.00% 1.35
Yield 3908 lb 27.00
Unit Weight 144.7lb//ft^(3)
Design Compressive Strength 5,000 psi
Design Slump 4 in.
Water/Cementitious Ratio 0.41 | Material Type | Description | Design Quantity | Specific Gravity | Volume ( $\mathrm{ft}^{3}$ ) |
| :---: | :---: | :---: | :---: | :---: |
| Cement | Type 1 | 526 lb | 3.15 | 2.68 |
| Fly Ash | Class C | 132 lb | 2.63 | 0.80 |
| Coarse Aggregate | #57 Limestone | 1900 lb | 2.69 | 11.32 |
| Fine Aggregate | Concrete Sand | 1083 lb | 2.64 | 6.57 |
| Water | Potable | 32 gal. | 1.00 | 4.28 |
| Admixture | Water Reducer | 26 oz | - | - |
| Admixture | Air Entraining | 3 oz | - | - |
| | | Air Content | 5.00% | 1.35 |
| | | Yield | 3908 lb | 27.00 |
| | | Unit Weight | $144.7 \mathrm{lb} / \mathrm{ft}^{3}$ | |
| Design Compressive Strength | | | 5,000 psi | |
| | | Design Slump | 4 in. | |
| Water/Cementitious Ratio | | | 0.41 | |
4 Test Section Construction 4 试验段建造
4.1 Excavation 4.1 挖掘
A 140 ft by 65 ft test section was constructed in ERDC’s Hangar 2 Accelerated Pavement Test Facility. The test section consisted of four lanes, each with a different pavement and subgrade combination that are described in detail in Chapter 2. 在 ERDC 的 2 号机库加速路面试验设施中建造了一个 140 英尺 x 65 英尺的试验段。试验段由四条车道组成,每条车道都有不同的路面和基层组合,详见第 2 章。 Excavation was completed to a depth of approximately 5 ft using a John Deere 130 G tracked excavator (Figure 10). The excavated area was uniformly graded using a motor grader and was recompacted using a smooth drum vibrator roller. 挖掘工作使用约翰迪尔 130 G 履带式挖掘机完成,深度约为 5 英尺(图 10)。使用平地机对挖掘区域进行均匀平整,并使用平滑鼓式振动压路机重新压实。 After excavation, the bottom and sides of the test section were lined with a 6 mil plastic sheeting to separate the natural subgrade from the constructed subgrade and to encapsulate the pavement test section to prevent moisture migration into/out of the design pavement layers. 挖掘完成后,在试验段的底部和两侧铺上 6 密耳塑料布,将天然路基与施工路基隔开,并将路面试验段封装起来,以防止湿气渗入/渗出设计路面层。
Figure 10. Test section excavation and preparation. 图 10.试验段的挖掘和准备工作。
(a) John Deere 130G tracked excavator (a) 约翰迪尔 130G 履带式挖掘机
(b) 6 mil plastic sheeting in bottom of excavation (b) 在挖掘底部铺设 6 密耳塑料布
4.2 Subgrade 4.2 基层
The CH material described in section 3.1 was used as the subgrade for the entire test section. As previously noted, two moisture contents were targeted to achieve 6 and 10 CBR. 3.1 节所述的 CH 材料被用作整个试验段的基层。如前所述,两种含水量分别用于达到 6 CBR 和 10 CBR。 Samples were taken from the stockpile to determine the natural moisture content by oven drying, ASTM D2216 (ASTM 2019), or microwave drying, ASTM D4643 (ASTM 2017d). 从堆放物中取样,通过烘箱干燥法(ASTM D2216,ASTM 2019)或微波干燥法(ASTM D4643,ASTM 2017d)测定天然含水量。 After determining the natural moisture content, the material was spread using multiple loaders to facilitate processing the material to the desired moisture content. 在确定天然含水量后,使用多台装载机将材料铺开,以便将材料加工成所需的含水量。 If the results of moisture content determinations indicated that the material was above the desired moisture content, natural drying of the material was allowed to occur. 如果含水量测定结果表明材料的含水量高于所需的含水量,则允许材料自然干燥。 If the results of moisture content determinations indicated the material was below the desired moisture content, water was added using 如果含水量测定的结果表明材料的含水量低于所需的含水量,则用
a hydroseeder. Mixing and tilling of the material was performed using a John Deere 6430 tractor with a Frontier RT2308 tiller attachment (Figure 11) to ensure a uniform moisture content was obtained throughout the material. 水力播种机。材料的混合和翻耕使用了配备 Frontier RT2308 翻耕机附件的约翰迪尔 6430 拖拉机(图 11),以确保整个材料的含水量均匀一致。 The material was tilled, restockpiled, respread, and tilled again to achieve moisture uniformity. This process was repeated multiple times until moisture uniformity was achieved. 对材料进行翻耕、重新堆放、重新摊铺和再次翻耕,以达到水分均匀。这一过程重复多次,直到达到水分均匀为止。 Moisture samples were taken frequently throughout the process to monitor changes in moisture content. 在整个过程中经常采集水分样本,以监测水分含量的变化。 After the material achieved the desired moisture content, it was stockpiled and covered with a heavy-duty tarp to mitigate moisture content changes prior to placement in the test section. 在材料达到所需的含水量后,将其堆放起来,并用厚重的防水布覆盖,以减缓材料在放入试验段前的含水量变化。
Figure 11. Mixing and processing equipment. 图 11.混合和加工设备。
To prepare the test section for subgrade placement, wooden grade stakes ensured each lift of clay was placed and compacted near a uniform height. Front-end loaders were used to place material within the test section. 为准备试验段的路基铺设,使用了木质标高桩,以确保每一车粘土都能以接近统一的高度铺设和压实。使用前端装载机在试验段内放置材料。 A CAT 277 Compact Track Loader (CTL) (Figure 12) was used to spread the clay in the test section. After each loose lift was placed, the material was compacted using an Ingram 10000 pneumatic roller and a Dynapac CA25 smooth wheel roller. 使用 CAT 277 紧凑型履带装载机(CTL)(图 12)在试验段铺设粘土。每次松土后,使用英格拉姆 10000 型气动压路机和戴纳派克 CA25 型光轮压路机对材料进行压实。 The Ingram 10000 pneumatic roller had a gross weight of approximately 70,000 lb applied to sets of pneumatic tires inflated to 120 psi. During the compaction process, a Troxler 3440 nuclear density gauge (ASTM D6938) was used to measure density (ASTM 2017b). 英格拉姆 10000 型气动压路机的总重量约为 70,000 磅,压在充气至 120 磅/平方英寸的充气轮胎上。在压实过程中,使用 Troxler 3440 核密度计(ASTM D6938)测量密度(ASTM 2017b)。 After completion of the compaction process for each lift, the clay layer was covered with 6 mil plastic sheeting to mitigate a loss of moisture from the placed clay layer. 在完成每次提升的压实过程后,用 6 密耳塑料布覆盖粘土层,以减少已铺设粘土层的水分流失。 Quality control testing was performed on each lift to ensure strength requirements were achieved and to measure uniformity throughout the test section. 对每次提升都进行了质量控制测试,以确保达到强度要求,并测量整个测试部分的均匀性。 The ASTM D4429 field CBR test (ASTM 2009a) was performed on each lift as a quality control test. After all lifts of the subgrade were completed, a motor grader was used to finalize the desired elevation of the test section. 作为质量控制测试,每次提升都进行了 ASTM D4429 现场 CBR 测试(ASTM 2009a)。在完成所有基层提升后,使用平地机最终确定试验段的理想标高。 Gauges were installed after the grading process was complete. 测量仪是在平整过程完成后安装的。
Figure 12. Material placement equipment. 图 12.材料放置设备。
After the subgrade was completed, an aggregate base layer was placed. The aggregate base layer was not processed to a desired moisture content outside of the test section. 基层铺设完成后,再铺设集料基层。试验段外的集料基层没有处理到理想的含水量。 Instead, the aggregate base layer was placed in the test section with a front-end loader and spread using a CTL. The aggregate base layer was compacted at its natural moisture content using a smooth drum vibratory roller. 而是用前端装载机在试验段铺设骨料基层,并用 CTL 进行摊铺。使用光滑钢轮振动压路机以自然含水量压实骨料基层。 A nuclear density gauge and CBR tests were performed to ensure strength requirements were achieved. A motor grader was used to achieve the final desired elevation. 为确保达到强度要求,还进行了核密度计和 CBR 测试。使用平地机达到最终预期的标高。
4.4 Surface Layers 4.4 表层
Placement of the PCC and HMA surface layers were completed by contracting local suppliers. ERDC personnel performed construction oversight and material acceptance. PCC 和 HMA 表层的铺设由当地供应商承包完成。ERDC 人员负责施工监督和材料验收。
5 Instrumentation 5 仪器
Instrumentation was installed to monitor pavement response during test section trafficking. Sensors installed in the rigid pavement test items included earth pressure cells (EPCs), surface strain gauges (SSG), and embedded strain gauges (ESG). 安装了仪器以监测试验段运输过程中的路面反应。刚性路面测试项目中安装的传感器包括土压力传感器 (EPC)、表面应变仪 (SSG) 和嵌入式应变仪 (ESG)。 Sensors installed in the flexible pavement test items included EPCs, SDDs, and asphalt strain gauges (ASGs). Pore-water pressure transducers, temperature sensors, and moisture sensors were installed to monitor environmental parameters. 柔性路面测试项目中安装的传感器包括 EPC、SDD 和沥青应变计 (ASG)。还安装了孔隙水压力传感器、温度传感器和湿度传感器来监测环境参数。 Figures 13 and 14 show the plan and profile view of the typical instrumentation layout for a rigid pavement test item, respectively. Figures 15 and 16 show the plan and profile view of the typical instrumentation layout for a flexible pavement test item, respectively. 图 13 和图 14 分别为刚性路面测试项目的典型仪器布局平面图和剖面图。图 15 和图 16 分别为柔性路面测试项目的典型仪器布局平面图和剖面图。
Figure 13. Plan view of typical PCC instrumentation layout. 图 13.典型 PCC 仪表布局平面图。
5.1 Subgrade and Base Vertical Pressure Cells 5.1 基层和基底垂直压力单元
Vertical stresses in the base course and subgrade were measured using 9 in. diam Geokon EPCs. EPCs provided a quantitative measurement of the vertical distribution of the stresses within each traffic lane during testing. 使用 9 英寸直径的 Geokon EPC 测量基层和路基的垂直应力。在测试过程中,EPC 对每条行车道内的应力垂直分布进行了量化测量。 Cells with a maximum pressure range up to 145 psi were installed in the subgrade of the PCC and HMA test items, and EPCs with a maximum pressure range of 325 psi were installed in the base course of the HMA test items. The EPCs in the base course were located 2 in . 在 PCC 和 HMA 测试项目的基层中安装了最大压力范围为 145 psi 的电池,在 HMA 测试项目的基层中安装了最大压力范围为 325 psi 的 EPC。基层中的 EPC 位于 2 英寸处。 below the top of the base and at middepth of the base course of the HMA test items. The EPCs placed in the subgrade of the PCC and HMA test items were located 2 in. below the top of the subgrade. Figure 12 shows an EPC being installed 2 in. 在 HMA 试验项目中,EPC 位于路基顶部以下 2 英寸处,而 HMA 试验项目中,EPC 位于路基中间深度处。放置在 PCC 和 HMA 试验项目基层中的 EPC 位于基层顶部下方 2 英寸处。图 12 显示了在 PCC 和 HMA 试验项目的路基下 2 英寸处安装的 EPC。 below the surface of the subgrade at the interface with the base course. 与基层交接处的基层表面以下。
Installation (Figure 17) commenced by locating each EPC at the preplanned station within each test item and carefully outlining the excavation area to minimize disturbance to adjacent soils. 开始安装时(图 17),先将每个 EPC 定位在每个测试项目内预先计划的站位上,并仔细划定挖掘区域的轮廓,以尽量减少对邻近土壤的干扰。 Measurements were made using a rod and level to determine pre-excavation elevation and to benchmark proper placement depth. 使用测量杆和水平仪进行测量,以确定挖掘前的标高,并确定适当的放置深度。 The EPC area was excavated to the target depth, the bottom of the excavation was carefully leveled, and a thin layer of clean sand was evenly spread to ensure the gauge maintained full contact with the underlying subgrade soils. Shallow trenches (approximately 1 in . 将 EPC 区域挖掘至目标深度,仔细平整挖掘底部,并均匀铺上一层薄薄的干净沙子,以确保测量仪与下层土壤保持充分接触。浅沟槽(约 1 英寸 . deep) were excavated to the edge of each test item for wire placement and protection from subsequent construction activities. After excavation was complete, an EPC was placed in the excavation, and its alignment was verified. 深)挖掘到每个测试项目的边缘,以便放置电线和保护其免受后续施工活动的影响。挖掘完成后,将 EPC 放入挖掘区,并对其进行校准。 Design subgrade soils were placed around each EPC and were compacted with a pneumatic hammer to minimize density variations in the disturbed area. 在每个 EPC 周围都放置了设计基层土壤,并用气动锤压实,以尽量减少扰动区域的密度变化。
Embedded concrete strain gauges, manufactured by Bridge Diagnostics Inc., were used to measure tensile strain near the bottom of the rigid pavement. Capable of measuring +-2,000\pm 2,000 microstrains, the gauges were 9 in. long and 桥梁诊断公司制造的嵌入式混凝土应变片用于测量刚性路面底部附近的拉伸应变。应变片长 9 英寸,可测量 +-2,000\pm 2,000 微应变。
were comprised of a full Wheatstone bridge circuit with four active 350 ohm strain gauges. Each gauge was installed 1 in . above the bottom of the concrete layer. 该系统由一个完整的惠斯通电桥电路和四个有源 350 欧姆应变片组成。每个应变片安装在混凝土层底部上方 1 英寸处。 Four-inch-long spikes with an oversized nut welded to the head of the spike were used to secure the gauges prior to concrete placement. Spikes were driven into the prepared base course such that the center of the welded nut was 1 in . above the prepared base course. 在浇筑混凝土之前,用四英寸长的钉子固定测量仪,钉子头部焊接一个特大号螺母。将钉子插入准备好的基层,使焊接螺母的中心高出准备好的基层 1 英寸。 The threaded ends of each concrete gauge were fed through the welded nut and a second nut was used to secure the threaded end of a concrete gauge. Lead wires from a gauge array were secured together and routed outside the test area. 每个混凝土压力表的螺纹端穿过焊接螺母,第二个螺母用于固定混凝土压力表的螺纹端。测量仪阵列的导线固定在一起,并引出测试区域。 Photographs of an embedded concrete strain gauge array are shown in Figure 18. 图 18 显示了嵌入式混凝土应变计阵列的照片。
(b) Strain array along traffic centerline (b) 沿交通中心线的应变阵列
SSGs were installed after completion of a 28 -day PCC curing period. SSGs consisted of a linear measurement gauge mounted on a polymide backing and were manufactured by HBM (model no. 1-LY43-6/350). SSG 是在 28 天的 PCC 固化期结束后安装的。SSG 由安装在聚酰亚胺衬底上的线性测量仪组成,由 HBM 制造(型号 1-LY43-6/350)。 The gauge locations were prepared by first filling surface voids in the PCC surface with a 5 min rapid-cure general purpose epoxy. After the epoxy sufficiently hardened, 120-grit sandpaper was used to smooth the area and eliminate surface irregularities during epoxy placement. 首先用 5 分钟快速固化的通用环氧树脂填充 PCC 表面的空隙,然后准备测量仪位置。环氧树脂充分硬化后,用 120 号砂纸将该区域磨平,消除环氧树脂涂抹过程中的表面不规则现象。 After the surface was determined to be sufficiently smooth, a rapid evaporating cleaner similar to acetone was used to remove debris and dust from the sanding operation. 在确定表面足够光滑后,使用类似丙酮的快速蒸发清洁剂清除打磨过程中产生的碎屑和灰尘。
After the surface was adequately cleaned, Devcon 5-min gel epoxy (No. 21045) was applied to the back of the gauge. A gauge was placed on the prepared location and Mylar tape was used to secure the gauge during adhesive curing. 表面充分清洁后,在仪器背面涂上 Devcon 5 分钟凝胶环氧树脂(编号 21045)。将仪器放在准备好的位置上,并在粘合剂固化期间使用 Mylar 胶带固定仪器。 A thin protective layer of adhesive was applied over the gauge and allowed to cure. At the conclusion of the adhesive cure period, the Mylar tape was removed. 在测量仪上涂上一层薄薄的粘合剂保护层,让其固化。粘合剂固化期结束后,撕下米拉胶带。 A protective coating that consisted of Micro-Measurements Gagekote #8 was applied over the entire gauge area while leaving the wire solder tabs exposed. 在整个量具区域涂上一层由 Micro-Measurements Gagekote #8 组成的保护层,同时将导线焊接片暴露在外。
Wires were soldered to the gauge tabs and a final coating of Gagekote #8 was applied over the gauge, solder tabs, and wire leads to provide a secondary protective coating. A layer of 1//8in1 / 8 \mathrm{in}. thick foam tape followed by a layer of aluminum foil tape was placed over the installed gauge to act as a mechanical barrier. Gagekote #8 was applied around the edges and seams of the tapes to mitigate moisture intrusion. 将导线焊接到仪器的焊片上,最后在仪器、焊片和导线上涂上一层 8 号 Gagekote,以提供二次保护涂层。在安装好的压力表上贴上一层 1//8in1 / 8 \mathrm{in} .厚的泡沫胶带,然后再贴上一层铝箔胶带,作为机械屏障。在胶带的边缘和接缝处使用了 8 号 Gagekote,以减少湿气侵入。
5.3 SDD
Vertical deflections in the subgrade were measured using SDDs assembled by ERDC. One SDD was placed in the middle of each test item along the centerline of traffic. The SDD was placed such that the shaft was anchored at a depth of 8 ft from the top of the subgrade. 使用 ERDC 装配的 SDD 测量路基的垂直变形。沿交通中心线在每个测试项目的中间放置一个 SDD。放置 SDD 时,轴锚定在距路基顶部 8 英尺处。 A linear variable displacement transducer (LVDT) with a range of +-1in\pm 1 \mathrm{in}. was placed in the housing such that it was in contact with both the anchor rod and the surface plate, as shown in Figure 19. Thus, the LVDT measured movement of the plate 2 in. below the base-subgrade interface relative to the control point located at a depth of 8 ft . 如图 19 所示,将量程为 +-1in\pm 1 \mathrm{in} . 的线性可变位移传感器 (LVDT) 放在外壳中,使其与锚杆和表面板接触。这样,LVDT 就能测量到位于基底界面下 2 英寸处的表板相对于位于 8 英尺深控制点的移动量。
Figure 19. SDD schematic. 图 19.SDD 原理图。
Like EPC installation, each SDD was located at a preplanned location and excavated such that the top of the removable access plate was 2 in. below the existing subgrade elevation. 与 EPC 安装一样,每个 SDD 都位于预先计划的位置,并进行挖掘,使可拆卸检修板的顶部低于现有基层标高 2 英寸。 A borehole was advanced at the center of the plate location to a depth of approximately 8 ft by using earth-auger drilling techniques. Rapid-setting concrete was placed in the borehole, and the instrument assembly was lowered to the target depth. 利用土钻技术,在平板中心位置钻孔,深度约为 8 英尺。在钻孔中放入速凝混凝土,然后将仪器组件下放到目标深度。 After the concrete had sufficiently cured, the LVDT was installed through a removable access plate such that the tip of the LVDT was in contact with the fixed anchor rod. Subgrade soils were then compacted over the surface of the SDD assembly. 混凝土充分固化后,通过可拆卸检修板安装 LVDT,使 LVDT 的尖端与固定锚杆接触。然后在 SDD 组件表面压实基层土壤。 Photographs summarizing SDD installation are shown in Figure 20. 图 20 是 SDD 安装的照片摘要。
Tensile strain at the bottom of an HMA layer provides a quantitative measure of the pavement response during trafficking. The tensile strain at the bottom of the HMA is a key response parameter linked to fatigue damage in the HMA layer. HMA 层底部的拉伸应变可定量测量路面在运输过程中的反应。HMA 层底部的拉伸应变是与 HMA 层疲劳损坏相关的关键响应参数。 For this study, strain at the bottom of the HMA surface was measured using dynamic ASGs in the longitudinal (i.e., with traffic) direction. The ASGs were manufactured by Tokyo Sokki and could measure a range of +-5,000\pm 5,000 microstrains. The gauges were adhered to the surface of the base course with a heated asphalt binder, and HMA from the asphalt paver was placed as cover over each of the gauges immediately prior to paving the entire test section. This process is shown in Figure 21. 在本研究中,使用动态 ASG 测量了纵向(即交通)HMA 表面底部的应变。ASG 由 Tokyo Sokki 制造,可测量 +-5,000\pm 5,000 微应变范围。测量仪用加热的沥青粘结剂粘附在基层表面,在摊铺整个试验段之前,立即将沥青摊铺机摊铺的 HMA 覆盖在每个测量仪上。此过程如图 21 所示。
Figure 21. ASG installation. 图 21.ASG 安装。
6 Pavement Characterization 6 路面特征描述
6.1 As-Built Properties 6.1 竣工属性
Quality control tests were performed during construction of each material lift to ensure target values were achieved and to monitor material consistency. 在每次材料提升施工过程中都进行了质量控制测试,以确保达到目标值并监测材料的一致性。 Dry density and moisture content were measured using a nuclear moisture density device in accordance with ASTM D6938 (ASTM 2017b) to verify the uniformity of each material lift. 使用符合 ASTM D6938(ASTM 2017b)标准的核水分密度装置测量了干密度和含水量,以验证每次材料提升的均匀性。 Field in-place CBR tests were performed in general accordance with ASTM D4429 (ASTM 2009a) on each compacted lift to ensure target values were achieved. 对每块压实土层都按照 ASTM D4429(ASTM 2009a)进行了现场 CBR 测试,以确保达到目标值。 To further characterize the strength of the completed base and subgrade layers, Dynamic Cone Penetrometer (DCP) tests were performed in accordance with ASTM D6951 (ASTM 2018). 为进一步确定已完成的基层和底基层的强度,根据 ASTM D6951(ASTM 2018)标准进行了动态锥入度计(DCP)测试。 HMA cores were obtained from each flexible pavement test item, and core densities were determined in accordance with AASHTO T166 (AASHTO 2016). 从每个柔性路面测试项目中获取 HMA 路芯,并根据 AASHTO T166(AASHTO 2016)确定路芯密度。 Unconfined PCC compressive strength was determined in accordance with ASTM C39 (ASTM 2021a), and PCC flexural strength was determined in accordance with ASTM C78 (ASTM 2021b). 抗压强度根据 ASTM C39(ASTM 2021a)测定,抗折强度根据 ASTM C78(ASTM 2021b)测定。 As-built properties are summarized in Table 4 for the rigid traffic lanes and Table 5 for the flexible traffic lanes. 表 4 和表 5 分别汇总了刚性车道和柔性车道的竣工属性。
6.2 DCP
A series of DCP tests was performed to characterize the strength of the unbound gravel pavement layers. DCP tests were performed after completion of HMA placement, following the procedures described by ASTM D 6951 (ASTM 2018). 进行了一系列 DCP 测试,以确定未粘结砾石路面层的强度。按照 ASTM D 6951(ASTM 2018)描述的程序,在完成 HMA 铺设后进行了 DCP 测试。 Measured values of the DCP index (millimeters of penetration per hammer blow) were converted to CBR strength by using the relationship developed by Webster et al. (1992) and Webster et al. (1994). 通过使用 Webster 等人(1992 年)和 Webster 等人(1994 年)建立的关系,将 DCP 指数的测量值(每锤击穿毫米)转换为 CBR 强度。
6.3 Falling-Weight Deflectometer 6.3 落锤式偏转仪
Falling-weight deflectometer (FWD) tests were performed on the surface of the test items after construction and prior to trafficking. 在施工后和运输前,对测试项目的表面进行了坠落重力挠度(FWD)测试。 The measured impulse stiffness modulus (ISM) was used to evaluate the stiffness of the constructed pavement section and to provide a baseline for subsequent comparison under traffic. 测得的脉冲刚度模量 (ISM) 用于评估已建路面的刚度,并为随后在交通状况下进行比较提供基线。 The ISM is the ratio of the applied load to the measured plate deflection with greater values representing a stiffer pavement structure. ISM results are discussed in Chapter 7. ISM 是施加荷载与测量板挠度的比值,数值越大代表路面结构越硬。第 7 章将讨论 ISM 结果。
6.4 Fresh PCC Test Results 6.4 新鲜 PCC 测试结果
Field tests were conducted during PCC placement to document the asdelivered properties and to verify consistency during the placement. Field tests included slump (ASTM 2020), temperature (ASTM 2017e), and air content (ASTM 2009b). 在铺设水泥混凝土期间进行了现场测试,以记录交付时的特性并验证铺设过程中的一致性。现场测试包括坍落度(ASTM 2020)、温度(ASTM 2017e)和空气含量(ASTM 2009b)。 Five compressive strength test cylinders and three flexural strength beams were cast for subsequent laboratory testing at each field test collection point. 在每个实地测试采集点,浇铸了五个抗压强度测试筒和三个抗弯强度梁,用于随后的实验室测试。 Three independent samples were obtained at approximately evenly spaced intervals (i.e., approximately every 60 cubic yd) during the concrete placement. The entire placement utilized a pump truck, and fresh PCC samples were obtained from the pump truck discharge pipe. 在混凝土浇筑过程中,以大致均匀的间隔(即大约每 60 立方码)采集了三个独立的样本。整个浇筑过程都使用了泵车,新鲜的 PCC 样品是从泵车的出料管中采集的。 A summary of field measurement test results is provided in Table 6. 表 6 提供了实地测量测试结果摘要。
Table 6. Results of fresh PCC field tests. 表 6.新鲜 PCC 实地测试结果。
Test No. 测试编号
Slump (in.) 坍落度(英寸)
Temperature (^(@)^(@):}\left({ }^{\circ}{ }^{\circ}\right. ) 温度 (^(@)^(@):}\left({ }^{\circ}{ }^{\circ}\right. )
Air Content (%) 空气含量 (%)
Set 1 第 1 套
9.0
76.3
3.8
Set 2 第二套
9.0
75.4
4.0
Set 3 第三套
9.5
76.2
4.5
Test No. Slump (in.) Temperature (^(@)^(@):} ) Air Content (%)
Set 1 9.0 76.3 3.8
Set 2 9.0 75.4 4.0
Set 3 9.5 76.2 4.5| Test No. | Slump (in.) | Temperature $\left({ }^{\circ}{ }^{\circ}\right.$ ) | Air Content (%) |
| :---: | :--- | :--- | :--- |
| Set 1 | 9.0 | 76.3 | 3.8 |
| Set 2 | 9.0 | 75.4 | 4.0 |
| Set 3 | 9.5 | 76.2 | 4.5 |
7 Traffic Testing 7 交通测试
Accelerated test traffic was applied using a dual-wheel P-8 gear mounted on ERDC’s HVS-A. The HVS is a fully automated pavement trafficking device capable of applying wheel loads ranging from 10,000 lbf to 100,000lbf100,000 \mathrm{lbf}. Total traffic length is approximately 45 ft at speeds ranging from 4 to 9 mph . Additionally, the HVS has an integrated climate control system that controls the temperature of the test area. 使用安装在 ERDC HVS-A 上的双轮 P-8 齿轮进行了加速试验交通。HVS 是一种全自动路面运输设备,能够施加 10,000 磅到 100,000lbf100,000 \mathrm{lbf} 不等的车轮载荷。总运输长度约为 45 英尺,速度范围为每小时 4 到 9 英里。此外,HVS 还有一个集成的气候控制系统,可以控制测试区域的温度。 While not critical for PCC pavement testing, HMA pavements are sensitive to fluctuations in pavement temperature. Thus, the climate control system was used to maintain the HMA pavement temperature at 77+-5^(@)F77 \pm 5^{\circ} \mathrm{F} during test section trafficking. An alarm system was activated to notify the operator if temperatures inside the test chamber exceeded the preset threshold. A photograph of the ERDC HVS-A is shown in Figure 22. 虽然 HMA 路面对 PCC 路面测试并不重要,但它对路面温度的波动非常敏感。因此,在试验段贩运期间,气候控制系统用于将 HMA 路面温度保持在 77+-5^(@)F77 \pm 5^{\circ} \mathrm{F} 。如果试验舱内的温度超过预设阈值,则会启动警报系统通知操作员。ERDC HVS-A 的照片见图 22。
The P-8 gear configuration used for trafficking all test items is shown in Figure 23. The P-8 gear consisted of two actual P-8 tires and wheels with a custom machined axle for securing the tires to the HVS carriage. The 用于运输所有测试项目的 P-8 齿轮配置如图 23 所示。P-8 齿轮包括两个实际的 P-8 轮胎和车轮,以及一个用于将轮胎固定到 HVS 支架上的定制加工轴。图 23
total load on the dual-wheel configuration was 89,000lbf89,000 \mathrm{lbf}; this load was verified prior to traffic testing using a set of portable aircraft scales. The tire inflation pressures were monitored daily and maintained at 220 psi . 双轮配置的总负载为 89,000lbf89,000 \mathrm{lbf} ;在交通测试前,使用一套便携式飞机秤对该负载进行了验证。每天对轮胎充气压力进行监测,并将其保持在 220 psi。
Figure 23. P-8 gear on HVS. 图 23.HVS 上的 P-8 齿轮。
Center-to-center spacing of the test tires was 39.5 in. This spacing was slightly greater than the actual tire spacing ( 33.5 in .) on the P-8 aircraft-a difference required to accommodate test gear mounting limitations on the HVS carriage. 测试轮胎的中心到中心间距为 39.5 英寸。这一间距略大于 P-8 飞机上的实际轮胎间距(33.5 英寸),这一差异是为了适应 HVS 支架上测试齿轮安装的限制。
Prior to test section trafficking, tire imprints (Figure 24a) were obtained on an HMA-surfaced test area to measure actual tire contact area. 在试验段贩运之前,在铺设了 HMA 面层的试验区采集轮胎印记(图 24a),以测量轮胎的实际接触面积。 The imprints were obtained by placing a thick piece of construction paper on the pavement surface, lowering the test gear, verifying the target load, and painting the tire outline with construction marking paint. 将一张厚建筑纸放在路面上,放下测试装置,确认目标载荷,然后用建筑标记漆涂抹轮胎轮廓,即可获得印记。 The tire imprint was photographed with a scale and loaded into a computer-aided drawing program to facilitate accurate contact area determination (Figure 24 b24 b ). A common assumption is that the tire contact area can be estimated by dividing the total wheel load by the tire inflation pressure; however, this assumption has been found to be inaccurate in some cases (Robinson 2021). 用刻度拍摄轮胎印记,并将其载入计算机辅助绘图程序,以便准确确定接触面积(图 24 b24 b )。一个常见的假设是,轮胎接触面积可以通过车轮总载荷除以轮胎充气压力来估算;但在某些情况下,这一假设并不准确(Robinson 2021)。 Thus, the tire imprints can be used to investigate P-8 contact area assumptions. 因此,轮胎印迹可用于研究 P-8 接触面积假设。
A summary of tire contact measurements obtained from the tire imprints is shown in Table 7. The measured total contact areas were found to be relatively close to the assumed contact areas (within 2.5%). When the tire tread pattern was removed from the area determination, 从轮胎印迹中获得的轮胎接触测量值汇总如表 7 所示。测量得出的总接触面积与假定接触面积比较接近(在 2.5% 以内)。在面积测定中去除轮胎胎面花纹、
researchers observed that the contact area was approximately 10%10 \% less than the assumed contact area. 研究人员观察到,接触面积比假定的接触面积大约小 10%10 \% 。
Figure 24. Tire imprint of the P-8 test gear. 图 24.P-8 试验齿轮的轮胎印。
(a) Tire imprints obtained from P-8 test gear (a) 从 P-8 试验装置上获得的轮胎印记
(b) Digital images made in a computer-aided drawing program (b) 用计算机辅助绘图程序制作的数字图像
Table 7. Measurements from digitized tire imprints. 表 7.数字化轮胎印记的测量结果。
Test Tire 测试轮胎
Length (in.) 长度(英寸)
Width (in.) 宽度(英寸)
总面积(英寸) ^(2)^{2}
Total Area
(in. ^(2)^{2} )
Total Area
(in. ^(2) )| Total Area |
| :---: |
| (in. $^{2}$ ) |
减去胎面的面积(英寸) ^(2){ }^{2} )
Area Minus
Tread (in. ^(2){ }^{2} )
Area Minus
Tread (in. ^(2) )| Area Minus |
| :---: |
| Tread (in. ${ }^{2}$ ) |
假定面积(英寸) ^(2){ }^{2}
Assumed
Area (in. ^(2){ }^{2} )
Assumed
Area (in. ^(2) )| Assumed |
| :---: |
| Area (in. ${ }^{2}$ ) |
Left Tire 左轮胎
18.6
12.6
206.8
182.0
202.3
Right Tire 右轮胎
18.4
12.4
199.1
179.5
202.3
Test Tire Length (in.) Width (in.) "Total Area
(in. ^(2) )" "Area Minus
Tread (in. ^(2) )" "Assumed
Area (in. ^(2) )"
Left Tire 18.6 12.6 206.8 182.0 202.3
Right Tire 18.4 12.4 199.1 179.5 202.3| Test Tire | Length (in.) | Width (in.) | Total Area <br> (in. $^{2}$ ) | Area Minus <br> Tread (in. ${ }^{2}$ ) | Assumed <br> Area (in. ${ }^{2}$ ) |
| :--- | :--- | :--- | :--- | :--- | :--- |
| Left Tire | 18.6 | 12.6 | 206.8 | 182.0 | 202.3 |
| Right Tire | 18.4 | 12.4 | 199.1 | 179.5 | 202.3 |
7.2 Wander Pattern 7.2 漫游模式
A bidirectional, normally distributed wander pattern was used to apply test traffic. Incorporating a wander pattern simulated the inherent variability 测试流量采用双向、正态分布的游移模式。采用游走模式模拟了固有的变异性
expected in a real-world trafficking scenario. The wander pattern used for this study is shown in Figure 25. 在真实世界的贩运场景中,这种模式是可以预期的。本研究采用的游走模式如图 25 所示。 The pattern consisted of a long sweep and a short sweep, where 158 total passes of the HVS comprised a full wander pattern resulting in a minimum pass-to-coverage ratio of 3.04. 该模式由长扫描和短扫描组成,高分辨率扫描仪的总扫描次数为 158 次,构成一个完整的扫描模式,最小扫描覆盖比为 3.04。
Traffic was started for each test item with the center of the dual-wheel P-8 gear aligned on the centerline of the test section. The HVS applied test traffic parallel to the test item centerline on the forward pass and shifted one end of the carriage beam 2 in . 每个测试项目的交通开始时,双轮 P-8 齿轮的中心对准测试部分的中心线。HVS 平行于测试项目中心线向前进行测试运输,并将车厢横梁的一端移动 2 英寸。 on the return pass. Prior to initiating the next pass, the opposite end of the carriage beam shifted 2 in .; thus, the beam returned parallel to the traffic centerline (Figure 26). 在返回通道上。在开始下一次通过之前,车厢横梁的另一端移动了 2 英寸;因此,横梁回到了与交通中心线平行的位置(图 26)。 This process was repeated throughout the entire wander pattern; therefore, odd pass numbers were parallel to the traffic centerline, and even pass numbers were at a slight skew to the traffic centerline. 因此,奇数通行号码与交通中心线平行,偶数通行号码与交通中心线略有倾斜。 It is important to understand the traffic operation and gear positioning of the HVS, particularly in early traffic and in relation to installed instrumentation, such that pertinent observations can be made. 重要的是要了解交通运行情况和 HVS 的齿轮定位,特别是在交通初期和与已安装的仪器相关的情况下,以便进行相关观察。
Results of trafficking tests to determine minimum pavement structural requirements are presented in this chapter. Data were interpreted to understand differences in pavement performance and instrumentation response under simulated aircraft trafficking. 本章介绍了为确定最低路面结构要求而进行的交通测试结果。对数据进行了解释,以了解路面性能和仪器在模拟飞机运输情况下的反应差异。 Inferences were made based on visual and measured responses. Data collected for this experiment are presented in tabular form in Appendix A through Appendix C. 根据视觉和测量的反应进行推断。本实验收集的数据以表格形式列于附录 A 至附录 C。
8.1 Rigid Pavement 8.1 硬质路面
Three levels of deterioration were considered in selecting passes to failure for a PCC test item. 在选择 PCC 测试项目的合格至不合格时,考虑了三个级别的劣化。 Deterioration levels were selected based on a review of historical full-scale testing (Rollings 1988) such that failure criteria were consistent with existing design criterion datasets. 根据对历史全尺寸测试的审查(Rollings,1988 年)选择了劣化等级,使失效标准与现有的设计标准数据集保持一致。 The first failure deterioration level considered was “first crack,” which was defined as when the absolute first crack was observed in 50%50 \% of the loaded test slabs. Note that in the case of this experiment, two loaded slabs comprised the traffic area; thus, 50%50 \% of the test slabs would be considered one slab. The second failure deterioration level considered was “shattered slab” and was defined as when sufficient inter-connected cracking had occurred to divide a slab into four distinct pieces. 考虑的第一个失效劣化等级是 "第一道裂缝",其定义是在 50%50 \% 加载测试板中观察到绝对第一道裂缝时。请注意,在本实验中,交通区域由两块加载板组成;因此, 50%50 \% 块测试板将被视为一块板。考虑的第二个失效劣化等级是 "碎裂板",其定义是发生足够多的相互连接的裂缝,将一块板分成四个不同的部分。 The third failure deterioration level considered was “complete failure” and was defined as when sufficient inter-connected cracking had occurred to divide a slab into six or more distinct pieces. 第三个失效劣化等级是 "完全失效",其定义是出现足够多的相互连接的裂缝,将板坯分成六个或更多不同的部分。
8.1.1 Lane 2 Item 1 (8 in. Thick PCC) 8.1.1 车道 2 项目 1(8 英寸厚 PCC)
Prior to applying simulated P-8 test traffic, a series of heavy-weight deflectometer (HWD) tests were conducted at strategic locations throughout the 8 in. thick PCC test item. 在进行模拟 P-8 试验交通之前,在整个 8 英寸厚的 PCC 试验项目的战略位置进行了一系列重型挠度计 (HWD) 测试。 The primary objectives were to evaluate pretraffic strength characteristics, to investigate the influence of the different joint construction techniques (dowelled and undowelled joints), and to investigate the influence of edge condition (free edge and confined edge). 主要目标是评估行车前的强度特性,研究不同接缝施工技术(注浆接缝和不注浆接缝)的影响,以及边缘条件(自由边缘和限制边缘)的影响。 Tests were conducted near the edges of the test area, midslab, and near each joint. ISM, which is simply the total load applied to the HWD test plate divided by the deflection measured at the center of the base plate, was used as the basis of comparison. 测试在测试区域的边缘、底板中部和每个接缝附近进行。ISM 是施加在 HWD 测试板上的总荷载除以在底板中心测得的挠度,用作比较的基础。 A graphical representation 图示
of the pretrafficking HWD test locations is shown in Figure 27. The test locations are represented by circles and are appropriately scaled to reflect position within the test item. The xx - and yy-axis dimensions are in feet, and numerical values adjacent to each circle are the calculated ISM values (with units of kips/in.) at each test location. A dashed line at an xx-coordinate of 20 represents the dowelled joint. 图 27 显示了人贩活动前的测试位置。测试位置用圆圈表示,并适当缩放以反映测试项目中的位置。 xx - 和 yy - 轴的尺寸单位为英尺,每个圆圈旁边的数值是每个测试位置的计算 ISM 值(单位为 kips/in.)。 xx -坐标为 20 的虚线代表锚固接头。
ISM values should be interpreted as greater values indicate a stiffer (i.e., stronger) pavement. In general, greater ISM values were observed adjacent to a confined edge, which was expected. For example, if one considers the test series conducted along an xx-distance of approximately 1 ft , one observes that the lowest ISM (i.e., 910kips//in910 \mathrm{kips} / \mathrm{in}.) was detected at x,yx, y coordinates of 1,4 that corresponded to a free-edge condition. As one moves up the yy-axis toward a confined edge, a general increase in ISM is observed. Similar observations can be made throughout the test item. ISM 值越大,说明路面越硬(即越结实)。一般来说,在封闭边缘附近观察到的 ISM 值更大,这是意料之中的。例如,如果考虑沿 xx 约 1 英尺距离进行的测试系列,就会发现在 x,yx, y 坐标为 1,4 处检测到最低的 ISM(即 910kips//in910 \mathrm{kips} / \mathrm{in} .当沿着 yy 轴向密闭边缘移动时,可以观察到 ISM 的普遍增加。在整个测试项目中也可以观察到类似的现象。
Midslab ISM values were generally greater values, as expected due to increased stiffness away from joints. The average midslab ISM value was 1,953 kips/in. compared to 1,763kips//in1,763 \mathrm{kips} / \mathrm{in}. along the dowelled joint and 1,104 kips/in. along the nondowelled joint. 正如预期的那样,由于远离接缝处的刚度增加,中层板的 ISM 值普遍较大。中层板的平均 ISM 值为 1 953 kips/in.
Dowel bar inclusion improved average measured ISM values by a factor of approximately 1.6 when compared to the nondowelled joint. This was expected as the primary purpose of dowel bars is to improve load transfer and stiffness along a joint. 与未铺设道钉的接合处相比,加入道钉后,ISM 的平均测量值提高了约 1.6 倍。这在意料之中,因为榫条的主要作用是改善连接处的荷载传递和刚度。
Similarly, HWD tests were conducted after the completion of traffic at the same locations allowing for meaningful comparisons. A graphical representation of posttraffic ISM values is shown in Figure 28. 同样,HWD 测试也是在相同地点的交通结束后进行的,以便进行有意义的比较。图 28 显示了交通结束后的 ISM 值。 In general, meaningful decreases in ISM were noticed throughout the test item, an observation expected as the pavement deteriorated. 总的来说,在整个测试项目中,ISM 都出现了有意义的下降,这也是随着路面老化而出现的现象。
The dowelled joint ISM values decreased by approximately 38%38 \% and represented the greatest observed percentage decrease. This can be attributed to interconnected cracking creating a host of small slab pieces as well as loss of load transfer with deterioration. Midslab ISM values decreased by approximately 26%26 \% and continued to have the greatest ISM values posttraffic. A 17%17 \% decrease in ISM was observed along the nondowelled joint and, although the nondowelled joint experienced the lowest percentage decrease, the magnitude of measured ISM was lowest overall. 卯榫连接的 ISM 值下降了约 38%38 \% ,是观察到的最大下降百分比。这可归因于相互连接的裂缝产生了大量小板块,以及恶化导致的荷载传递损失。中层楼板的 ISM 值下降了约 26%26 \% ,并且在交通流过后仍具有最大的 ISM 值。沿着无下水道连接处观察到 ISM 下降了 17%17 \% ,尽管无下水道连接处的下降百分比最低,但测量的 ISM 值总体上最低。
Similarly, joint load transfer efficiency (JE) in both a pretraffic and posttraffic condition were evaluated using HWD data (Table 8). In this case, joint transfer efficiency referred to the ratio of measured deflection measured equidistant on each side of a joint. 同样,使用 HWD 数据对交通前和交通后条件下的接缝荷载传递效率(JE)进行了评估(表 8)。在这种情况下,接缝传递效率指的是在接缝两侧等距离测量的挠度比率。 Thus, deflection data were taken from the sensor located on the HWD load plate (i.e., D_(0)\mathrm{D}_{0} ) and deflections measured one foot away (i.e., D_(1)\mathrm{D}_{1} ) from the plate. The HWD was positioned such that the load plate was on one side of a joint and sensor D_(1)D_{1} was positioned on the opposite side of a joint. 因此,挠度数据取自位于 HWD 承重板上的传感器(即 D_(0)\mathrm{D}_{0} )和距承重板一英尺处测量的挠度(即 D_(1)\mathrm{D}_{1} )。HWD 的定位方式是,载荷板位于接头的一侧,传感器 D_(1)D_{1} 位于接头的另一侧。
Initial JE was found to be greater in the dowelled joint (average =0.94=0.94 ) than the nondowelled joint (average =0.77=0.77 ), as expected. Similarly, posttest data indicated that JE remained greater in the dowelled joint (average =1.09=1.09 ) than the nondowelled joint (average =0.89=0.89 ) at the conclusion of traffic. An improvement in JE was observed in the nondowelled joint with an increase in traffic and cracking in the vicinity of the joint, which was not expected. 结果发现,正如预期的那样,加固接头的初始 JE(平均 =0.94=0.94 )大于未加固接头(平均 =0.77=0.77 )。同样,后测数据表明,在交通结束时,加固关节的 JE(平均 =1.09=1.09 )仍然大于未加固关节(平均 =0.89=0.89 )。随着交通量的增加和接缝附近裂缝的出现,未铺设下沉胶的接缝的 JE 有所改善,这是不在预料之中的。 Team members hypothesize that cracking around the joint resulted in movement of individual pieces of the concrete slab in the joint vicinity under HWD loading. This movement resulted in greater contact forces at the joint, thereby increasing frictional load transfer. 小组成员推测,接合处周围的裂缝导致接合处附近的混凝土板块在重载下发生移动。这种移动导致接缝处的接触力增大,从而增加了摩擦荷载的传递。
Figure 27. Pretraffic HWD results (8 in. thick PCC). 图 27.交通前 HWD 结果(8 英寸厚 PCC)。
Figure 28. Posttraffic HWD results (8 in. thick PCC). 图 28.行车后 HWD 结果(8 英寸厚 PCC)。
Table 8. HWD joint load transfer efficiency results (8 in. thick PCC). 表 8.HWD 接头荷载传递效率结果(8 英寸厚 PCC)。
Visual inspections were conducted routinely to monitor crack development. Each visual inspection consisted of a full examination of the test area, and, if a crack was identified, it was marked with striping paint, mapped, and measured. These observations were then used to 为监测裂缝发展情况,定期进行目视检查。每次目视检查都包括对测试区域进行全面检查,如果发现裂缝,则用条纹漆对其进行标记、绘图和测量。然后根据这些观察结果
create electronic crack maps. Thus, accurate crack progression could be cataloged via a computer-aided drawing program. 创建电子裂缝图。这样,就可以通过计算机辅助绘图程序对裂纹的发展过程进行精确编目。
The first crack was observed during the 500-pass inspection radiating from the undowelled joint in a “half-moon” pattern and extending across the traffic area. 在进行 500 次检查时,发现第一条裂缝从未消化的接缝处呈 "半月形 "辐射开来,并延伸至整个交通区域。 Researchers noted that the crack was not present at the 300-pass inspection; thus, the crack manifested somewhere between 300 and 500 passes. 研究人员注意到,在 300 次检查时,裂纹并没有出现;因此,裂纹是在 300 至 500 次检查之间出现的。
A second crack was observed at 546 passes on the opposite side of the undowelled joint in the same half-moon pattern. As traffic continued, secondary cracks began to form both parallel to the initial cracks and migrating from the initial cracks. 在第 546 次通行时,在未铺胶接缝的另一侧观察到了第二道裂缝,裂缝呈相同的半月形。随着车流的继续,开始出现与初始裂缝平行的次生裂缝,并从初始裂缝向外延伸。 At the 3,000-pass level inspection, one slab had enough interconnected cracks to be divided into four individual pieces, achieving the shattered slab failure definition. 在 3,000 次检测中,有一块楼板出现了足够多的相互连接的裂缝,被分成了四块,达到了破碎楼板失效的定义。 At the 7,500-pass level inspection, the cracks had become interconnected to a point that the test area achieved the complete failure condition in which the slab was divided into six or more distinct pieces. All cracks were low severity cracks (crack width less than 1//81 / 8 in.), and no foreign object debris (FOD) development was observed. Maps showing the location and progression of crack development are shown in Figures 29 through 36. 在 7500 次检查中,裂缝已相互连接,以至于测试区域达到了完全失效的状态,即板坯被分成六个或更多不同的部分。所有裂缝都是低严重性裂缝(裂缝宽度小于 1//81 / 8 英寸),没有发现异物碎屑 (FOD) 出现。图 29 至图 36 显示了裂缝的位置和发展过程。
Figure 29. Crack map at 500 passes. 图 29.500 次通过时的裂缝图。
Figure 30. Crack map at 546 passes. 图 30.546 个通道的裂缝图。
Figure 31. Crack map at 750 passes. 图 31.750 通过点的裂缝图。
Figure 32. Crack map at 2,000 passes. 图 32.2,000 通过点的裂缝图。
Figure 33. Crack map at 3,000 passes. 图 33.3,000 通过点的裂缝图。
Figure 34. Crack map at 7,500 passes. 图 34.7500 米处的裂缝图。
Figure 35. Crack map at 10,000 passes. 图 35.万次通过时的裂缝图。
Figure 36. Crack map at 15,000 passes. 图 36.15000 通过点的裂缝图。
Additionally, cumulative crack length over the test item area was measured at select traffic intervals and plotted as shown in Figure 37. Total crack length generally increased from 500 to 750 passes. Thereafter, a modest increase was observed up to approximately 2,000 passes. 此外,还在选定的行车间隔时间测量了测试项目区域的累积裂缝长度,并绘制成图 37。总裂缝长度一般在 500 到 750 次之间增加。此后,在大约 2,000 次测试之前,裂缝长度会略有增加。 Crack length development tended to increase thereafter up to the suspension of traffic. 此后,裂缝长度的发展呈上升趋势,直至交通中断。
A review of the crack maps and crack progression data assisted in determining a proper pass level to assign the various failure conditions. 对裂纹图和裂纹发展数据的审查有助于确定适当的合格级别,以确定各种失效条件。
A summary of the selected pass levels for each failure condition is provided in Table 9. 表 9 提供了针对每种故障条件所选择的合格级别的摘要。
Table 9. Selected failure pass level for 8 in. thick PCC. 表 9.8 英寸厚 PCC 的选定失效合格级别。
Figure 37. Total crack length with traffic (8 in. thick PCC). 图 37.交通情况下的总裂缝长度(8 英寸厚 PCC)。
8.1.1.3 FWD Results 8.1.1.3 FWD 结果
Falling-weight deflectometer data were collected at select traffic intervals during traffic application to monitor structural deterioration. An FWD was used during traffic application in lieu of a HWD due to clearance requirements under the HVS. 在行车过程中,在选定的行车间隔时间收集了坠重挠度计数据,以监测结构的恶化情况。由于 HVS 的净空要求,在行车过程中使用了 FWD 来代替 HWD。 FWD measurements were made at the dowelled joint, midslab, quarter-slab, and the nondowelled joint. A summary of ISM values for each condition with cumulative traffic passes is shown in Figure 38. FWD 测量是在下沉接缝、板中、四分之一板和无下沉接缝处进行的。图 38 显示了每种条件下的 ISM 值和累计交通通过量。
Initial measured ISM values in the midslab and quarter-slab locations were the highest measured values in most cases, and midslab values were greater than quarter-slab values. 在大多数情况下,楼板中部和四分之一楼板位置的初始测量 ISM 值是最高测量值,而且楼板中部的值大于四分之一楼板的值。 This was expected and attributed to increased stiffness as the test locations moved further from a joint (i.e., deflections decreased further from a joint.) The nondowelled joint had the lowest measured ISM, which is logical considering the nondowelled joint relied on interface friction to generate stiffness. 这在意料之中,并可归因于测试位置离连接处越远,刚度越大(即离连接处越远,挠度越小)。无压痕连接处测得的 ISM 最低,考虑到无压痕连接处依靠界面摩擦力产生刚度,这是合乎逻辑的。 Measured ISM values near the dowelled joint were slightly less than those measured at the midslab and quarter-slab locations; however, the data showed a meaningful stiffness improvement when compared to the nondowelled joint. 与中层板和四分之一层板位置的测量值相比,下沉接缝附近的 ISM 测量值略低;不过,与未下沉接缝相比,数据显示刚度有了明显改善。
ISM values tended to decrease with an increase in traffic and an increase in pavement deterioration (i.e., cracking.) Meaningful decreases in ISM were observed in the dowelled joint, midslab, and quarter slab locations with an increase in cumulative traffic, initiating between the 1,000- and 2,500-pass level and continuing through traffic completion. 随着交通量的增加和路面破损(即开裂)的加剧,ISM 值呈下降趋势。随着累计交通量的增加,在卯榫接缝、中层板和四分之一板位置观察到 ISM 值明显下降,从 1,000 到 2,500 次通行水平之间开始下降,并持续到交通结束。
Interestingly, decreases in measured ISM at the nondowelled joint did not display similar trends which was unexpected. However, a review of the measured JE with increased traffic (Figure 39) revealed that joint transfer generally improved in the nondowelled joint. 有趣的是,非消音接头处测量的 ISM 下降并没有显示出类似的趋势,这出乎意料。然而,随着流量的增加,对测量的 JE 进行复查(图 39)后发现,未覆膜接合处的接合传递总体上有所改善。 It is hypothesized that cracking in the vicinity of the nondowelled joint resulted in slight movement of the individual slab pieces, thereby improving interlock in the measurement area. 据推测,无缝连接处附近的裂缝导致单个板块发生轻微移动,从而改善了测量区域的互锁性。 Note that a decrease in ISM at the nondowelled joint was observed near the 500-pass level, which was when the first crack was identified. Thereafter, as increased cracking occurred a rebound in stiffness was observed, which could support the previous hypothesis. 需要注意的是,在接近 500 次通过水平时,即发现第一条裂缝时,观察到非消音接头处的 ISM 有所下降。此后,随着裂纹的增加,观察到刚度有所回升,这可能支持了之前的假设。 Near the end of traffic as extensive cracking occurred, the team observed that all ISM values tended to converge. 在交通接近尾声时,随着大面积开裂的出现,研究小组观察到所有的 ISM 值都趋于一致。
Figure 38. ISM with traffic at various locations (8 in. thick PCC). 图 38.不同位置的交通 ISM(8 英寸厚 PCC)。
Figure 39. JE with traffic for dowelled and nondowelled joints (8 in. thick PCC). 图 39.交通情况下的 JE(8 英寸厚 PCC)。
8.1.1.4 Subgrade Pressure Response 8.1.1.4 基层压力响应
A summary of measured subgrade pressure is shown in Figure 40. Representative subgrade response values were determined by selecting the greatest measured response near the end of each selected traffic interval. 测得的路基压力摘要如图 40 所示。通过选择每个选定交通量区间末期的最大测量响应值,确定了具有代表性的路基响应值。 Thus, the values represent a “best hit” when the test gear was directly over a subgrade EPC. Response values were calculated by subtracting the peak value and the minimum value for the event; thus, values represent dynamic measurements. 因此,这些数值代表了当测试装置直接位于路基 EPC 上时的 "最佳击打"。响应值的计算方法是减去事件的峰值和最小值;因此,数值代表动态测量值。
Maximum measured subgrade pressure was relatively consistent early in traffic (up to approximately 250 passes). Thereafter, an increase in measured pressure was observed to the completion of traffic. 测量到的最大路基压力在行车初期(大约 250 次)相对稳定。此后,直到交通结束,测得的压力都在增加。 A meaningful increase in measured pressure was observed at the quarter-slab location near 2,500 passes, which corresponded with a shattered slab condition (see north slab observations in Table 9). 在接近 2,500 通过点的四分之一楼板位置,测得的压力有明显增加,这与楼板破碎的情况相吻合(见表 9 中的北楼板观测结果)。 A similar response can be observed between 6,000 and 7,500 passes for the midslab pressure cell (south slab). Thus, the earth pressure cell data agree with visual cracking observations. 在楼板中部压力单元(南楼板)的 6000 和 7500 次之间也可以观察到类似的反应。因此,土压力单元的数据与目视裂缝观测结果一致。
Comparison of the pressure cell locations indicated that maximum measured pressure tended to diverge near 2,500 passes. Greater measured pressures were observed at the quarter slab location after 2,500 passes, which corresponded with differences in observed cracking. 对压力单元位置的比较表明,最大测量压力在接近 2,500 道次时趋于偏离。在 2,500 次之后,在四分之一板位置观察到更大的测量压力,这与观察到的裂缝差异相符。 These data suggest that as cracking increased beyond the shattered slab condition, the load-carrying capability of the slabs decreased, and more of the applied load was transmitted to the underlying subgrade layer. 这些数据表明,随着裂缝的增加,超过了板的破碎状态,板的承载能力就会下降,更多的外加荷载就会传递到下面的基层。
Figure 40. Subgrade pressure response with traffic (8 in. thick PCC). 图 40.交通对路基压力的影响(8 英寸厚 PCC)。
8.1.1.5 SSG Response 8.1.1.5 SSG 响应
SSG response data for the nondowelled joint, dowelled joint, and midslab measurement locations are shown in Figures 41 to 43, respectively. As expected, the SSGs failed relatively early in the trafficking sequence. 无下沉接头、下沉接头和板中测量位置的 SSG 响应数据分别如图 41 至图 43 所示。不出所料,SSG 在贩运过程中相对较早出现故障。 In general, measured response at the three measurement locations were similar in magnitude. Generally increasing trends were observed to the point of gauge failure. 总体而言,三个测量点的测量响应在幅度上相似。一般来说,在水位计失灵之前,测量值呈上升趋势。 The gauges mounted adjacent to the dowelled joint provided data up to approximately 1,000 passes; values ranged from 200 to 300 microstrains at gauge failure. 安装在镙丝连接处附近的测量仪可提供多达约 1,000 次的数据;测量仪失效时的微应变值从 200 到 300 不等。
Figure 41. SSG response of nondowelled joint (8 in. thick PCC). 图 41.无冲洗接头的 SSG 响应(8 英寸厚 PCC)。
Figure 42. SSG response of dowelled joint (8 in. thick PCC). 图 42.螺纹连接的 SSG 响应(8 英寸厚 PCC)。
Figure 43. SSG response of midslab (8 in. thick PCC). 图 43.中层板(8 英寸厚 PCC)的 SSG 响应。
8.1.1.6 ESG Response 8.1.1.6 ESG 答复
ESG response for the nondowelled, dowelled, and midslab measurement locations are shown in Figures 44 to 46, respectively. 图 44 至图 46 分别显示了无下沉、下沉和板中测量位置的 ESG 响应。 A review of the nondowelled joint response (Figure 44) revealed a considerable amount of data scatter, and response values ranged from less than 100 microstrains to approximately 550 microstrains. 对无冲压连接响应的审查(图 44)显示了大量的数据分散,响应值从不到 100 微应变到大约 550 微应变不等。 Of note, the data were generally consistent up to approximately 300 passes becoming much more variable thereafter. This could be an indication of damage (i.e., occurrence of cracking near the nondowelled joint prior to migrating to the surface.) 值得注意的是,大约 300 次之前的数据基本一致,之后的数据变化较大。这可能是损坏的迹象(即,在向表面迁移之前,在非消光接缝附近出现裂纹)。
A review of the dowelled joint and midslab data indicate that similar strain magnitudes and trends were observed at these measurement locations. 通过对螺纹连接和中层板数据的审查发现,在这些测量位置观察到了类似的应变幅度和趋势。 This suggests that dowel bar inclusion was effective at stiffening the pavement joint and that the joint behaved as a monolithic structure (i.e., the joint behavior was like a nonjointed area.) Like the nondowelled response, the dowelled response and midslab response tended to trend upward around 300 passes potentially indicating the start of pavement deterioration. 这表明掺入镙丝条可有效加固路面接缝,并且接缝表现为整体结构(即接缝表现类似于非接缝区域)。与未掺入镙丝条的响应一样,掺入镙丝条的响应和中层板响应在 300 次左右呈上升趋势,这可能表明路面开始老化。
Figure 44. ESG response of nondowelled joint (8 in. thick PCC). 图 44.无冲洗接头的 ESG 响应(8 英寸厚 PCC)。
Figure 45. ESG response of dowelled joint (8 in. thick PCC). 图 45.锚固接头的 ESG 响应(8 英寸厚 PCC)。
Figure 46. ESG response of midslab (8 in. thick PCC). 图 46.中层板(8 英寸厚 PCC)的 ESG 响应。
8.1.2 Lane 2 Item 2 (11 in. Thick PCC) 8.1.2 车道 2 项目 2(11 英寸厚 PCC)
8.1.2.1 HWD Results 8.1.2.1 HWD 结果
Prior to applying P-8 test traffic, a series of HWD tests were conducted at strategic locations throughout the 11 in. thick PCC test item. 在使用 P-8 试验流量之前,在整个 11 英寸厚 PCC 试验项目的战略位置进行了一系列 HWD 试验。 These tests quantified pretraffic strength characteristics, interrogated the influence of the difference joint construction techniques (dowelled and undowelled joints), and examined the influence of edge condition (free edge and confined edge). 这些测试量化了交通前的强度特征,分析了不同接缝施工技术(打线和不打线接缝)的影响,并检查了边缘条件(自由边缘和限制边缘)的影响。 Tests were conducted near the edges of the test area, midslab, and near each joint. A graphical representation of the pretraffic HWD test locations is shown in Figure 47. 测试在测试区域的边缘、板中和每个接缝附近进行。图 47 显示了交通前 HWD 测试位置的图示。 The test locations are represented by circles and are appropriately scaled to reflect position within the test item. The xx - and yy-axis dimensions are in feet, and numerical values adjacent to each circle are the calculated ISM values (in kips/in.) at each test location. Greater ISM values indicate a stiffer (stronger) pavement. 测试位置用圆圈表示,并适当缩放以反映测试项目中的位置。 xx - 和 yy - 轴的尺寸单位为英尺,每个圆圈旁边的数值是每个测试位置的计算 ISM 值(单位为 kips/in.)。ISM 值越大,表示路面越硬(越结实)。
As expected, midslab ISM values were generally the greatest observed values; this is attributed to increased overall stiffness away from a joint. The average midslab ISM value was 3,412 kips/in., compared to 2,041 kips/in. along the dowelled joint and 2,263 kips/in. 正如预期的那样,中层板的 ISM 值通常是观测到的最大值;这归因于远离连接处的整体刚度增加。板中层的平均 ISM 值为 3,412 kips/in.,相比之下,锚固连接处的平均 ISM 值为 2,041 kips/in.,锚固连接处的平均 ISM 值为 2,263 kips/in.。 along the nondowelled joint. 沿着无缝连接处。
Dowel bar inclusion did not result in an improvement in average measured ISM values, an unexpected result. However, this suggests that the undowelled joint was not fully cracked prior to traffic application. 加入道钉条并没有改善测量的平均 ISM 值,这是一个出乎意料的结果。不过,这表明未加道钉的接缝在通车前并没有完全裂开。
Similarly, HWD tests were conducted after the completion of traffic at the same locations making meaningful comparisons possible. A graphical representation of posttraffic ISM values is shown in Figure 48. 同样,HWD 测试也是在相同地点的交通结束后进行的,因此可以进行有意义的比较。图 48 显示了交通结束后的 ISM 值。 In some cases, meaningful decreases in ISM were observed while in others, increases in ISM were observed. 在某些情况下,ISM 出现了有意义的下降,而在另一些情况下,ISM 则出现了上升。
Average dowel joint ISM values decreased by approximately 31%31 \% and average undowelled joint ISM values decreased by approximately 53%53 \%. Average midslab ISM values had a modest 1%1 \% increase after completion of traffic application, essentially no change. These data suggest that the joints were deteriorating with the application of traffic when compared to the midslab data. 榫接平均 ISM 值下降了约 31%31 \% ,未榫接平均 ISM 值下降了约 53%53 \% 。在完成交通应用后,中层板的平均 ISM 值略有 1%1 \% 增加,基本上没有变化。这些数据表明,与中层楼板的数据相比,接缝随着交通的应用而恶化。
Figure 47. Pretraffic HWD results (11 in. thick PCC). 图 47.交通前 HWD 结果(11 英寸厚 PCC)。
Figure 48. Posttraffic HWD results (11 in. thick PCC). 图 48.行车后 HWD 结果(11 英寸厚 PCC)。
Results of HWD JE measurements are presented in Table 10. Pretraffic results indicated that the average JE was nearly equivalent in the dowelled and nondowelled joint. These data suggest that the nondowelled joint had not cracked full depth prior to traffic application. HWD JE 测量结果见表 10。行车前的结果表明,注浆接缝和未注浆接缝的平均 JE 几乎相等。这些数据表明,在通车前,未消隐接缝尚未完全裂开。 Posttraffic JE data indicated that the dowelled joint tended to maintain relatively good JE at the conclusion of traffic, while a meaningful reduction in JE was observed in the nondowelled joint. 行车后的 JE 数据表明,在行车结束后,加固接头往往能保持相对较好的 JE,而未加固接头的 JE 则明显减少。
Table 10. HWD joint load transfer efficiency results (11 in. thick PCC). 表 10.HWD 接头荷载传递效率结果(11 英寸厚 PCC)。
Joint Condition 关节状况
Location 地点
JE ( D_(1)//D_(0)\mathrm{D}_{1} / \mathrm{D}_{0} )
Visual inspection, conducted throughout all traffic intervals, did not discover any cracking on the surface of the 11 in . thick PCC test item. 在所有行车间隔期间进行的目测检查均未发现 11 英寸厚的 PCC 测试项目表面有任何裂缝。
8.1.2.3 FWD Results 8.1.2.3 FWD 结果
FWD data were collected at select traffic intervals during traffic application to monitor structural deterioration; an FWD was used during traffic application in lieu of a HWD due to clearance requirement under the HVS. 在行车过程中,在选定的行车间隔时间采集了全回转支承数据,以监测结构劣化情况;在行车过程中使用全回转支承代替高回转支承,这是因为 HVS 的净空要求。 Measurements were made at the dowelled joint, midslab, quarter-slab, and the nondowelled joint. A summary of ISM values for each condition with cumulative traffic passes is shown in Figure 49. 测量是在榫接、中层、四分之一层板和无榫接处进行的。图 49 显示了各种条件下的 ISM 值和累积交通通过量。
The greatest measured ISM values were observed at the midslab and quarter-slab locations throughout traffic application. 在整个交通应用过程中,在楼板中部和四分之一楼板位置测得的 ISM 值最大。 ISM values were observed to be generally consistent throughout traffic application, and a slight decrease in measured ISM at the midslab and quarter-slab locations was observed near the 20,000-pass data collection point. 据观察,在整个流量应用过程中,ISM 值基本保持一致,在接近 20,000 次数据采集点时,在中层和四分之一层位置测得的 ISM 值略有下降。 However, the visual inspection did not discover any indications of deterioration. 不过,目测检查并未发现任何老化迹象。
Interestingly, the nondowelled joint location had a greater pretraffic ISM than the dowelled joint location, suggesting that the nondowelled joint may not have been fully cracked at traffic initiation. 有趣的是,无下沉接头位置的交通前 ISM 比有下沉接头位置大,这表明无下沉接头在交通开始时可能还没有完全裂开。 As increased traffic was applied, ISM values at the two joint conditions tended to converge. ISM values at each joint location were less than both the midslab and quarter slab locations throughout traffic application. 随着交通量的增加,两种连接条件下的 ISM 值趋于一致。在整个交通应用过程中,每个接缝位置的 ISM 值都小于中板和四分之一板位置的 ISM 值。
JE with traffic is shown in Figure 50. The data tend to indicate that JE on the dowelled joint remained relatively consistent throughout traffic application, suggesting that little to no damage was imparted on the dowelled joint. 图 50 显示了交通情况下的 JE。数据倾向于表明,在整个行车过程中钉接接头的 JE 保持相对一致,这表明钉接接头几乎没有受到损坏。 The nondowelled joint experienced a decline in JE throughout traffic application. Relatively high JE values early in traffic suggest that the saw-cut joint had not cracked full-depth prior to traffic. 在整个行车过程中,未冲洗接缝的 JE 值一直在下降。行车初期相对较高的 JE 值表明,锯切接缝在行车前尚未完全裂开。 The decline in JE was indicative of the saw-cut crack propagating full depth during traffic application. JE 值的下降表明锯切裂缝在施工过程中扩展到了整个深度。
Figure 49. ISM with traffic at various locations (11 in. thick PCC). 图 49.不同位置的交通 ISM(11 英寸厚 PCC)。
Figure 50. JE with traffic for dowelled and nondowelled joints (11 in. thick PCC). 图 50.交通情况下的 JE(11 英寸厚的 PCC)。
8.1.2.4 Subgrade Pressure Response 8.1.2.4 基层压力响应
A summary of measured subgrade pressure is shown in Figure 51. Representative subgrade response values were determined by selecting the highest measured response near the end of each selected traffic interval. 测得的路基压力摘要如图 51 所示。通过选择每个选定交通区间接近终点时的最高测量响应值,确定了具有代表性的路基响应值。 Thus, the values represent a “best hit” when the test gear was directly over a subgrade EPC. Response values were calculated by subtracting the peak value from the minimum value for the event; thus, values represent dynamic measurements. 因此,这些数值代表了当测试装置直接位于路基 EPC 上时的 "最佳响应"。响应值的计算方法是用事件的最小值减去峰值;因此,数值代表的是动态测量值。
The maximum measured subgrade pressures were relatively consistent throughout traffic application. 在整个交通应用过程中,测得的最大路基压力相对一致。 Measured midslab values were relatively low (approximately 2 psi ) for a majority of traffic applications, and a modest increase (approximately 1 psi ) was observed later in traffic application. 在大多数交通应用中,测量到的中层板值相对较低(约 2 psi),在交通应用的后期观察到中层板值略有增加(约 1 psi)。 An EPC located at the dowelled joint was slightly greater (on the order of 4 psi ) near the start of traffic and increased to approximately 7 psi near the end of traffic. The measured values in both cases are relatively low, suggesting that the 11 in . 在交通开始时,位于镙丝连接处的 EPC 稍大(约 4 psi),在交通结束时增加到约 7 psi。这两种情况下的测量值都相对较低,表明 11 in . thick PCC was sufficiently thick to reduce pressure applied to the subgrade thus limiting potential deterioration in the subgrade layer. 厚的 PCC 足够厚,可以减少施加在基层上的压力,从而限制基层可能出现的损坏。
Figure 51. Subgrade pressure response with traffic (11 in. thick PCC). 图 51.交通对路基压力的影响(11 英寸厚 PCC)。
8.1.2.5 SSG Response 8.1.2.5 SSG 响应
SSG response data for the nondowelled joint, dowelled joint, and midslab measurement locations are shown in Figure 52 to Figure 54, respectively. As expected, the SSGs failed relatively early in the traffic sequence. 图 52 至图 54 分别显示了无下沉接头、下沉接头和板中测量位置的 SSG 响应数据。不出所料,SSG 在交通序列中相对较早出现故障。
A review of the SSG data generally showed that measured strains were consistent at all measurement locations. A comparison of the nondowelled and dowelled joint response data indicates a similar response was recorded, which agreed with measured FWD data. 对 SSG 数据的审查总体上表明,所有测量位置的测量应变都是一致的。对无下沉和下沉接头响应数据的比较表明,记录的响应类似,这与测量的 FWD 数据一致。
Figure 52. SSG response of nondowelled joint (11 in. thick PCC). 图 52.无冲洗接头的 SSG 响应(11 英寸厚 PCC)。
Figure 53. SSG response of dowelled joint (11 in. thick PCC). 图 53.螺纹连接的 SSG 响应(11 英寸厚 PCC)。
Figure 54. SSG response of midslab (11 in. thick PCC). 图 54.中层板(11 英寸厚 PCC)的 SSG 响应。
8.1.2.6 ESG Responses 8.1.2.6 ESG 答复
ESG responses for the dowelled and midslab measurement locations are shown in Figures 55 and 56, respectively. An error in the instrument layout during construction resulted in failure to collect ESG data for the nondowelled joint. 图 55 和图 56 分别显示了下沉式和中层板测量位置的 ESG 响应。由于施工过程中仪器布局的错误,导致未能收集到非下沉连接处的 ESG 数据。
Measured response early in traffic was similar for both measurement locations. With increasing traffic levels, little to no meaningful changes were observed in strain gauge response at the midslab locations, suggesting that no internal deterioration occurred at midslab. 两个测量位置在交通初期的测量反应相似。随着交通流量的增加,中层位置的应变计响应几乎没有发生有意义的变化,这表明中层没有发生内部退化。 An increase in measured strain response was observed near 1,000 passes at the dowelled joint; however, a visual inspection did not identify deterioration (cracking in the vicinity of the joint). 在靠近 1,000 道次的下钉接头处,测量到的应变响应有所增加;但是,目测检查并未发现恶化现象(接头附近出现裂纹)。
Figure 55. ESG response of dowelled joint (11 in. thick PCC). 图 55.锚固接头的 ESG 响应(11 英寸厚 PCC)。
Figure 56. ESG response of midslab (11 in. thick PCC). 图 56.中层板(11 英寸厚 PCC)的 ESG 响应。
8.1.3 Lane 1 Item 1 (14 in. Thick PCC) 8.1.3 车道 1 项目 1(14 英寸厚 PCC)
Because of the extensive number of traffic passes applied to the 11 in. thick PCC test item and the lack of observed deterioration, it was determined to not traffic the 14 in. thick PCC test item. 由于对 11 英寸厚的 PCC 测试项目进行了大量的交通测试,而且没有观察到老化现象,因此决定不对 14 英寸厚的 PCC 测试项目进行交通测试。
8.2 Flexible Pavement 8.2 柔性路面
Failure of the flexible pavement test items was defined as 1 in . of rutting for a permanent operation scenario and 2 in . of rutting for a contingency operation scenario. 柔性路面测试项目的失效定义为:在永久运行情况下,车辙深度为 1 英寸;在应急运行情况下,车辙深度为 2 英寸。 Rutting included both permanent deformation in the wheel path and upheaval outside the wheel path (Figure 57). Rutting magnitude was measured at multiple locations in each test item using a 12 ft long aluminum straightedge and a machined depth wedge. 车辙包括车轮轨迹内的永久变形和车轮轨迹外的动荡(图 57)。使用 12 英尺长的铝直尺和机加工深度楔在每个测试项目的多个位置测量车辙幅度。
Figure 57. Example of rut-depth and permanent-deformation measurement. 图 57.车辙深度和永久变形测量示例。
8.2.1 Rutting 8.2.1 车辙
Rut-depth progression for the flexible pavement test items is presented in Figure 58. Similarly, a summary of P-8\mathrm{P}-8 passes required to produce various rut depths is presented in Table 11. Rut depths were selected to match those currently defined as threshold values for varying levels of pavement condition determination: low ( 0.25 in. to 0.5 ), medium ( 0.5 in. to 1.0 in.), and high ( > 1.0>1.0 in.). 图 58 显示了柔性路面测试项目的车辙深度变化。同样,表 11 列出了产生不同车辙深度所需的 P-8\mathrm{P}-8 通过量摘要。选择的车辙深度与目前定义为不同路面状况判定级别的阈值相匹配:低(0.25 英寸至 0.5 英寸)、中(0.5 英寸至 1.0 英寸)和高( > 1.0>1.0 英寸)。
Rapid rut development was observed in the test items constructed with the GR base. The 2 in. thick HMA test item with the gravel base sustained approximately 0.5 in. of rutting for each pass of the P-8 test gear. 在使用 GR 路基的试验项目中,车辙发展迅速。使用砾石路基的 2 英寸厚 HMA 试验项目在每次通过 P-8 试验齿轮时都会产生约 0.5 英寸的车辙。 An increase in HMA thickness was found to improve rutting performance, although the passes to failure remained relatively low. When traditional failure criteria are considered, (1.0 in. rutting) the 2 in. 研究发现,增加 HMA 厚度可改善车辙性能,但失效通过率仍然相对较低。如果考虑传统的失效标准(1.0 英寸车辙),则 2 英寸 HMA 路面的失效标准为 1.0 英寸车辙。 thick HMA test item with the gravel base was capable of sustaining only two passes of the P-8 test gear, and the 4 in. thick HMA test item sustained eight passes of the P-8 test gear. If contingency operations are considered (on the order of 2.0 in. of rutting), the 2 in. 带碎石底层的厚 HMA 试验项目仅能承受 P-8 试验齿轮两次通过,而 4 英寸厚 HMA 试验项目则能承受 P-8 试验齿轮八次通过。如果考虑到应急操作(车辙深度约为 2.0 英寸),2 英寸厚的 HMA 试验项目只能承受 P-8 试验齿轮的两次通过。 thick HMA test item with the gravel base sustained four passes of the P-8 test gear, and the 4 in. thick HMA test item sustained 20 passes of the P-8 test gear. 带碎石底座的厚 HMA 试验项目在 P-8 试验装置上可持续通过 4 次,而 4 英寸厚 HMA 试验项目在 P-8 试验装置上可持续通过 20 次。 Thus, pavements containing weak base layers (CBR values of approximately 30) should not be expected to sustain a meaningful number of P-8\mathrm{P}-8 operations without encountering heavy rutting damage. Visual inspection during traffic application revealed meaningful instability in the pavement evidenced by pumping of the surface. 因此,对于含有薄弱基层(CBR 值约为 30)的路面来说,在不出现严重车辙损坏的情况下,不可能持续多次 P-8\mathrm{P}-8 作业。在施工期间进行的目视检查发现,路面存在明显的不稳定性,表现为路面抽水。 Additionally, the pavement instability resulted in the HVS having extreme difficulty traversing the pavement test section. 此外,路面的不稳定性导致 HVS 在穿越路面试验段时极为困难。
A meaningful improvement in rutting performance was observed when the base-course layer strength was increased. The 2 in. thick HMA and 4 in. thick HMA test items constructed with a highquality crushed limestone base over 10 CBR subgrade sustained over 200 passes for the 当基层强度增加时,车辙性能会有明显改善。厚度为 2 英寸的 HMA 和厚度为 4 英寸的 HMA 试验项目在 CBR 值为 10 的基层上使用优质碎石石灰基层,其车辙性能超过 200 次。
1.0 in. rutting criteria. This result highlights the importance of a competent aggregate base layer for heavy aircraft loads. Comparatively, the 2 in. thick HMA test item and 4 in. thick test item with the crushed limestone base sustained a similar number of passes to 1 in. 1.0 英寸车辙标准。这一结果表明,对于重型飞机载荷而言,合格的集料基层非常重要。相比之下,2 英寸厚的 HMA 试验项目和 4 英寸厚的碎石基试验项目承受的车辙通过次数与 1 英寸厚的 HMA 试验项目相似。 rut depth, and, unexpectedly, the 2 in. thick HMA test item sustained 260 passes compared to 222 passes in the 4 in. thick HMA test item. 出乎意料的是,2 英寸厚的 HMA 试验项目持续通过 260 次,而 4 英寸厚的 HMA 试验项目仅通过 222 次。 This suggests that at greater subgrade CBR values, pavement rutting performance becomes less sensitive to HMA layer thickness, particularly at lower levels of rutting. After 1 in . of rutting occurred, the performance was similar for the 2 in . thick and 4 in . 这表明,当基层 CBR 值越大,路面车辙性能对 HMA 层厚度的敏感性就越低,尤其是在车辙程度较低的情况下。出现 1 英寸车辙后,2 英寸厚和 4 英寸厚的路面性能相似。 thick HMA test items further implying that pavement performance becomes less sensitive to HMA thickness at greater subgrade CBR values. 这进一步表明,当基层 CBR 值越大时,路面性能对 HMA 厚度的敏感性就越低。
Reduction in subgrade strength from 10 to 6 CBR resulted in an approximate 60%60 \% to 70%70 \% reduction in passes to 1 in . rut depth. For 2 in. of HMA and a limestone base, the item with 6 CBR subgrade sustained 79 passes to 1 in . rut depth, and the item with 10 CBR subgrade sustained 260 passes. For 4 in. 将基层强度从 10 CBR 降低到 6 CBR,可使车辙深度达到 1 英寸的通过次数减少约 60%60 \% 至 70%70 \% 。对于 2 英寸 HMA 和石灰石基层,采用 6 CBR 基层的项目在达到 1 英寸车辙深度时可通过 79 次,而采用 10 CBR 基层的项目可通过 260 次。对于 4 英寸厚的 HMA 和石灰岩基底,使用 6 CBR 路基的项目可承受 79 次碾压,达到 1 英寸车辙深度。 of HMA with the limestone base, the item with 6 CBR subgrade sustained 99 passes to 1 in . rut depth, and the item with 10 CBR subgrade sustained 222 passes. Similar trends were observed beyond 1 in . rut depth. In the case of contingency operations (allowing up to 2.0 in. 在采用石灰岩基层的 HMA 路面上,采用 6 CBR 基层的路面在车辙深度达到 1 英寸时可持续通过 99 次,而采用 10 CBR 基层的路面则可持续通过 222 次。车辙深度超过 1 英寸后也观察到类似的趋势。在应急作业(允许最大车辙深度为 2.0 英寸)的情况下,车辙深度超过 1 英寸的情况也是如此。 of rut depth), then reduction in subgrade CBR results in approximately 50%50 \% reduction in passes to failure. 的车辙深度),那么路基 CBR 的降低大约会导致 50%50 \% 失效通过次数的减少。
These rutting performance data indicate that a competent base layer is required to sustain a reasonable number of P-8\mathrm{P}-8 operations. 这些车辙性能数据表明,要维持合理的 P-8\mathrm{P}-8 作业次数,需要一个合格的基层。 The drastic difference in pavement rutting performance suggests that for the case of new construction, aggregate base layer materials should be required to meet existing materials specifications (i.e., CBR values ranging from 80 to 100.) Further, the data indicate that the HMA layer should be at least 4 in. 路面车辙性能的巨大差异表明,对于新建工程,骨料基层材料应符合现有材料规格(即 CBR 值在 80 到 100 之间)。 thick to support a minimum of 500 operations of a P-8 aircraft in a contingency scenario. 厚,以支持 P-8 飞机在紧急情况下至少进行 500 次操作。
Figure 58. Rut-depth progression with traffic. 图 58.有交通流量的车辙深度变化。
Table 11. Passes required to produce various rut depths. 表 11.产生不同车辙深度所需的通过次数。
Note: Values interpolated from measured rut-depth data. 注:根据测量的车辙深度数据内插的数值。
8.2.2 ISM
FWD data were collected to monitor overall structural deterioration with increasing traffic levels. 收集了 FWD 数据,以监测随着交通流量的增加,整体结构的恶化情况。 FWD data were collected at the locations of installed instrumentation in each test item so that pavement stiffness and instrumentation response were collected at the same locations. 在每个测试项目中安装仪器的位置收集 FWD 数据,以便在相同位置收集路面刚度和仪器响应。 Average ISM values for each test item were calculated and used for analysis as presented in Figure 59. An attempt was made to collect FWD data at each 如图 59 所示,每个测试项目的平均 ISM 值均已计算并用于分析。尝试在每个测试点收集 FWD 数据。
traffic collection point; however, significant pavement deterioration prevented successful FWD operation on occasion. 然而,路面的严重破损有时会阻碍 FWD 的成功运行。
Initial pretraffic ISM values for the gravel base test items were low, as expected. The FWD identified changes in HMA thickness; a greater initial ISM value was noted in the 4 in. thick HMA test item compared to the 2 in. thick HMA test item over the gravel base. 正如预期的那样,砾石路基测试项目的交通前初始 ISM 值较低。FWD 确定了 HMA 厚度的变化;与砾石路基上 2 英寸厚的 HMA 测试项目相比,4 英寸厚的 HMA 测试项目的初始 ISM 值更大。 Loss of strength was observed with increasing passes, and the ISM of the 4 in. thick HMA test item approached the ISM of the 2 in. thick HMA test item at the completion of test traffic. 随着通过次数的增加,观察到强度下降,4 英寸厚 HMA 测试项目的 ISM 在测试交通结束时接近 2 英寸厚 HMA 测试项目的 ISM。
An increase in base course strength resulted in a meaningful increase in pavement stiffness. Initial ISM values in the 4 in. thick HMA test item with the limestone base over a 10 CBR subgrade were approximately 200 kips/in. 基层强度的增加会显著提高路面刚度。在 CBR 值为 10 的基层上铺设石灰石基层的 4 英寸厚 HMA 试验项目中,初始 ISM 值约为 200 kips/in。 greater than those observed in the comparative pavement section with gravel base. A similar trend was observed in the 2 in. thick HMA test items. Overall, the 4 in. thick HMA over limestone base over 10 CBR subgrade test item had the highest ISM value as expected. The 4 in. 比使用砾石路基的对比路面断面中观察到的更大。在 2 英寸厚的 HMA 测试项目中也观察到类似的趋势。总体而言,石灰岩基层上的 4 英寸厚 HMA 超过 10 CBR 基层测试项目的 ISM 值最高。4 英寸厚的 HMA thick HMA item remained the best performer throughout traffic application, although a decline in stiffness was observed. A similar rate of stiffness decline was observed in the 2 in. thick HMA test item. 在整个交通应用过程中,厚 HMA 项目的性能仍然最好,但刚度有所下降。在 2 英寸厚的 HMA 试验项目中也观察到了类似的刚度下降率。
The FWD detected a reduction in subgrade CBR; a decrease in subgrade CBR from 10 to 6 resulted in a decrease in initial ISM. Notably, initial ISM values in the 4 in. thick HMA over 6 CBR subgrade test item were nearly equivalent to those measured in the 2 in . FWD 检测到了路基 CBR 的降低;路基 CBR 从 10 降到 6 导致了初始 ISM 的降低。值得注意的是,6 CBR 以上 4 英寸厚 HMA 路基试验项目中的初始 ISM 值与 2 英寸厚 HMA 路基试验项目中的初始 ISM 值几乎相同。 thick HMA over 10 CBR subgrade test item suggesting that increasing the subgrade CBR provided a stiffness enhancement equivalent to an additional 2 in. of HMA. 厚 HMA 超过 10 CBR 路基测试项目表明,增加路基 CBR 带来的刚度增强相当于增加 2 英寸 HMA。
However, the team observed that as passes increased and pavement deterioration accumulated, ISM values tended to converge regardless of pavement cross section except for the 4 in . thick HMA over LS over 10 CBR test item. 不过,研究小组观察到,随着通过次数的增加和路面损坏程度的累积,ISM 值趋于趋同,无论路面横截面如何,但 4 英寸厚的 HMA 碾压 LS 超过 10 CBR 的测试项目除外。 These data support the recommendation that to support a meaningful number of P-8 operations, a minimum 4 in. thick HMA layer over a competent base layer and a relatively stiff subgrade is required. 这些数据支持这样的建议,即要支持一定数量的 P-8 作业,就必须在合格的基层和相对坚硬的路基上铺设至少 4 英寸厚的 HMA 层。
Figure 59. ISM with traffic. 图 59.有流量的 ISM。
8.2.3 Subgrade pressure response 8.2.3 基层压力响应
Subgrade vertical pressure response data are presented in Figure 60. When interpreting the maximum subgrade response, it is important to understand the P-8\mathrm{P}-8 gear position in relation to instrumentation location early in traffic application. The initial traffic pass was applied with the center of the test gear located at the centerline of the test item; thus, a test tire was not positioned directly over the installed instrumentation. 图 60 显示了路基垂直压力响应数据。在解释最大路基响应时,重要的是要理解 P-8\mathrm{P}-8 齿轮位置与交通应用早期仪器位置的关系。初始交通通过时,测试齿轮的中心位于测试项目的中心线上;因此,测试轮胎并没有直接位于已安装的仪器上方。 As each additional traffic pass was applied, the HVS shifted the P-8 gear approximately 2 in. laterally in the wander pattern. Thus, the increase in measured pressure observed early in traffic could be attributed to a test tire moving closer to the installed instrumentation. 每增加一次行车,HVS 就会在游移模式中横向移动 P-8 档位约 2 英寸。因此,在行车初期观察到的测量压力增加可能是由于测试轮胎靠近了安装的仪器。 Peak initial measured pressure (near 20 passes) occurred when a P-8 tire was directly over the installed instrumentation. Data presented after 100+ passes represent the maximum observed response or “best hit” during application of a full traffic pattern. 当 P-8 轮胎直接位于安装的仪器上方时,初始测量压力达到峰值(接近 20 次)。100 次以上测试后的数据代表在应用全流量模式时观察到的最大响应或 "最佳响应"。
In all cases, an increase in measured subgrade vertical pressure response was observed as the test gear shifted closer to the subgrade EPC, and subgrade pressure tended to reach a steady state thereafter. 在所有情况下,当测试装置移动到更靠近路基 EPC 的位置时,测得的路基垂直压力响应都会增加,此后路基压力趋于稳定状态。 Minor variation in measured subgrade pressure was observed with an increase in traffic 随着交通量的增加,测得的路基压力略有变化
application; however, definitive trends could not be identified. In general, measured subgrade pressure ranged from approximately 50 to 80 psi . 但是,无法确定明确的趋势。一般来说,测得的路基压力大约在 50 至 80 psi 之间。
Figure 60. Measured subgrade pressure response with traffic. 图 60.测量到的路基压力随交通量的变化情况。
A series of equality plots were generated to aid understanding the effect of differing pavement cross-section properties on measured subgrade pressure. Equality plots are useful in interpreting the effect of HMA thickness and subgrade strength on measured subgrade pressure. 生成了一系列等值线图,以帮助理解不同路面横截面特性对测量路基压力的影响。等值图有助于解释 HMA 厚度和路基强度对测量路基压力的影响。 Note that limited data were available for the gravel base test items due to rapid pavement failure; thus, equality plots for those data were not generated. 请注意,由于路面迅速损坏,砾石路基测试项目的数据有限,因此没有生成这些数据的等值图。
Figures 61 and 62 present equality plots to investigate the effect of HMA thickness for the limestone base test items with a 6 CBR subgrade and 10 CBR subgrade, respectively. 图 61 和 62 分别显示了 6 CBR 基层和 10 CBR 基层石灰岩基层测试项目的等值图,以研究 HMA 厚度的影响。 In both cases measured subgrade pressure early in traffic (lower measured pressure response) were generally clustered around the line of equality (LOE). 在这两种情况下,交通初期测得的路基压力(较低的测得压力响应)一般都集中在等压线(LOE)附近。 Later in traffic application (greater measured pressure response), it was observed that the data tended to trend below the LOE, indicating measured subgrade pressure was consistently less in the 4 in. 在交通应用的后期(测得的压力响应更大),观察到数据趋向于低于 LOE,表明在 4 英寸路面上测得的路基压力始终较小。 thick HMA test items. In the 10 CBR subgrade comparison, the data tended to be further from the LOE, suggesting the influence of HMA thickness was more pronounced with an increase in subgrade CBR. 厚的 HMA 测试项目。在 10 CBR 路基比较中,数据往往与 LOE 相差较远,表明随着路基 CBR 的增加,HMA 厚度的影响更加明显。
Figures 63 and 64 present equality plots to investigate the effect of subgrade CBR for the limestone base test items with a 4 in. thick HMA and 2 in. thick HMA layer, respectively. 图 63 和图 64 分别显示了 4 英寸厚 HMA 层和 2 英寸厚 HMA 层石灰岩基层试验项目的等值图,以研究基层 CBR 的影响。 Measured subgrade pressure early in traffic application tended to be near the LOE, and measured subgrade pressure diverged from the LOE later in traffic application. 在交通应用初期测量的路基压力往往接近 LOE,而在交通应用后期测量的路基压力则偏离 LOE。 In both cases, the data plotted below the LOE indicating that an increase in subgrade CBR resulted in an increase in measured subgrade pressure. The difference tended to be more pronounced in the 2 in. 在这两种情况下,绘制的数据都低于 LOE,表明路基 CBR 的增加会导致测得的路基压力增加。这种差异在 2 in. thick HMA comparison suggesting that measured subgrade pressure in thinner HMA pavement sections is more sensitive to subgrade CBR. 厚 HMA 比较表明,在较薄的 HMA 路面断面上测量的路基压力对路基 CBR 更为敏感。
Figure 61. Subgrade pressure-effect of HMA thickness for LS base, 6 CBR subgrade. 图 61.LS 基层、6 CBR 基层的 HMA 厚度对基层压力的影响。
Figure 62. Subgrade pressure-effect of HMA thickness for LS base, 10 CBR subgrade. 图 62.LS 基层、10 CBR 基层的 HMA 厚度对基层压力的影响。
Figure 63. Subgrade pressure-effect of subgrade CBR for 4 in. HMA, LS base. 图 63.4 英寸 HMA、LS 基层的基层压力对基层 CBR 的影响。
Figure 64. Subgrade pressure-effect of subgrade CBR for 2 in. HMA, LS base. 图 64.2 英寸 HMA、LS 基层的基层压力对基层 CBR 的影响。
A statistical analysis of measured subgrade pressure response (Table 12) was conducted to determine if observed differences were statistically significant. 对测量的路基压力响应进行了统计分析(表 12),以确定观察到的差异是否具有统计意义。 A paired T-test was used because response measurements were collected at the same traffic interval, and similar construction techniques were used for all test items. A two-tailed rejection region was considered (i.e., the average difference between the observed values was zero.) All statistical measures were evaluated at alpha=0.05\alpha=0.05. It should be noted that comparisons that included the 2HMA over GR over 10 CBR test item had a small sample size due to rapid failure; thus, the robustness of the statistical comparison should be interpreted with caution. 之所以采用配对 T 检验,是因为在相同的交通时间间隔内收集了响应测量值,而且所有测试项目都采用了类似的构建技术。所有统计量都在 alpha=0.05\alpha=0.05 时进行评估。值得注意的是,由于快速失效,包括 2HMA over GR over 10 CBR 测试项目的比较样本量较小;因此,应谨慎解释统计比较的稳健性。
In the case of comparisons made to the 4HMA over GR over 10 CBR test item (Table 12), researchers found that all the limestone base test items had statistically lower subgrade pressures. 在与 4HMA over GR over 10 CBR 测试项目进行比较时(表 12),研究人员发现所有石灰岩路基测试项目的路基压力在统计上都较低。
Direct comparison of subgrade strength found that both the 4 in. thick HMA and 2 in. thick HMA resulted in statistically different average subgrade pressure. In both cases, researchers found that the 6 CBR subgrade yielded lower average subgrade pressure response. 对基层强度进行直接比较后发现,4 英寸厚的 HMA 和 2 英寸厚的 HMA 在统计上导致了不同的平均基层压力。在这两种情况下,研究人员都发现 6 CBR 路基产生的平均路基压力响应较低。
Comparison of HMA thickness found that an increase in HMA thickness resulted in statistically different average subgrade pressure on both a 6 and 10 CBR subgrade. In both cases, the 4 in. thick HMA test item was found to be the better performer as expected. 对 HMA 厚度进行比较后发现,HMA 厚度增加会导致 6 CBR 和 10 CBR 基层的平均基层压力出现统计学差异。在这两种情况下,都发现 4 英寸厚的 HMA 测试项目如预期的那样性能更好。
Table 12. Statistical analysis of subgrade pressure response. 表 12.路基压力响应的统计分析。
Base vertical pressure response data measured at the top of the base layer are presented in Figure 65. As noted with subgrade pressure response, early pressure measurements were a function of wheel position. Like subgrade pressure response, an increase in measured 在基层顶部测量的基层垂直压力响应数据见图 65。与路基压力响应一样,早期压力测量值是车轮位置的函数。与路基压力响应一样,测得的
pressure was observed as the test wheel moved closer to the earth pressure cell. Thereafter, a steady-state condition was achieved, and reported pressures represent the maximum observed pressure during a respective traffic interval. 当测试车轮靠近土压力池时,观察到压力增大。此后,压力达到稳定状态,所报告的压力为各交通区间内观测到的最大压力。
Some variability was observed in the top of base measured response and could be attributed to material movement in the base course layer. 在测量的基底顶部反应中观察到了一些变化,这可能是由于基底层中的材料移动造成的。 Visual observation suggested that during traffic application there was meaningful movement in the pavement that was a function of the dual-wheel configuration. 目测结果表明,在行车过程中,路面有明显的移动,这与双轮配置有关。 Researchers hypothesize there was a “kneading” action from the dual-wheel (material was in a state of upheaval at times and in a state of deformation at times) that was a function of the wander pattern and wheel position. 研究人员假设,双轮(材料时而处于起伏状态,时而处于变形状态)产生了一种 "揉捏 "作用,这种作用与游走模式和轮子位置有关。 Thus, sensors placed higher in the pavement would be expected to be more sensitive to wheel wander. In general, it was observed that top-ofbase pressures ranged from approximately 150 psi to nearly 230 psi . 因此,放置在路面较高位置的传感器预计会对车轮晃动更加敏感。一般来说,观察到的底座顶部压力范围从大约 150 psi 到接近 230 psi 不等。
Figure 65. Measured top-of-base pressure response with traffic. 图 65.测量到的基底顶部压力随交通量的变化情况。
Equality plots for top-of-base pressure measurements are presented in Figure 66 through Figure 69. A review of Figures 66 and 67 provides insight into the effect of HMA thickness on 6 CBR subgrade and 10 CBR subgrade, respectively. In both cases, early data fall above the LOE, 图 66 至图 69 显示了基底顶部压力测量的等值图。通过查看图 66 和图 67,可分别了解 HMA 厚度对 6 CBR 基层和 10 CBR 基层的影响。在这两种情况下,早期数据都高于 LOE、
indicating that measured pressures were greater in the 4 in. thick HMA test items when compared to the 2 in. thick HMA test items. While this was not expected, recall that in initial traffic the test wheels were not directly over the EPC. 表明与 2 英寸厚的 HMA 测试项目相比,4 英寸厚的 HMA 测试项目的测量压力更大。虽然这是意料之外的,但请记住,在初始交通中,测试车轮并不直接位于 EPC 上。 Thus, this could be attributed to differences in subsurface stress distribution that were a function of the dual-wheel gear configuration. 因此,这可能是由于双轮齿轮配置导致的地下应力分布差异造成的。 Later in traffic at greater pressure levels, the data tend to cluster below the LOE indicating that greater pressure were measured in the 2 in. thick HMA test items, as expected. 在较大压力水平的交通后期,数据往往集中在 LOE 以下,表明如预期的那样,在 2 英寸厚的 HMA 测试项目中测得了较大的压力。 In both cases, the data tended to be similar distances from the LOE suggesting that subgrade CBR did not have a meaningful effect on top of base measured pressure. 在这两种情况下,数据与 LOE 的距离趋于相近,这表明基层 CBR 对基底顶面测量压力的影响不大。 A review of Figures 68 and 69 confirms this suspicion because the steady-state data tended to be clustered both above and below the LOE. 图 68 和图 69 证实了这一猜测,因为稳态数据往往集中在 LOE 以上和以下。
Figure 66. Top-of-base pressure-effect of HMA thickness for LS base, 6 CBR subgrade. 图 66.LS 基底、6 CBR 基层的基底压力对 HMA 厚度的影响。
Figure 67. Top-of-base pressure-effect of HMA thickness for LS base, 10 CBR subgrade. 图 67.LS 基底、10 CBR 基层的基底压力对 HMA 厚度的影响。
Figure 68. Top-of-base pressure-effect of subgrade CBR for 4 in. HMA, LS base. 图 68.4 英寸 HMA、LS 基底的基底压力对基底 CBR 的影响。
Figure 69. Top-of-base pressure-effect of subgrade CBR for 2 in . HMA, LS base. 图 69.2 英寸 HMA、LS 基底的基底压力对基底 CBR 的影响。
A statistical analysis of top-of-base pressure response is presented in Table 13. A comparison of subgrade strength found that differences in base pressure response were significant in the 2 in. thick HMA sections ( p=0.020p=0.020 ) and that the 10 CBR subgrade resulted in a lower average top of base pressure. Comparison of the 4 in . thick HMA test item was unremarkable ( p=0.236p=0.236 ) suggesting that subgrade CBR did not influence top-of-base pressure with a thicker HMA layer. 表 13 列出了对基底顶部压力响应的统计分析。通过比较路基强度发现,2 英寸厚 HMA 路段的基底压力响应差异显著( p=0.020p=0.020 ),10 CBR 路基的平均基底压力较低。4 英寸厚 HMA 测试项目的比较结果并不显著( p=0.236p=0.236 ),这表明路基 CBR 不会影响较厚 HMA 层的基底顶压力。
Similarly, if direct comparisons are made for HMA thickness on the same subgrade CBR value, it is observed that for the 6-CBR subgrade increasing HMA thickness did not result in a statistically significant difference in average top-of-base pressure ( p=0.508p=0.508 ). Comparison of the 10 CBR subgrade was found to be statistically significant ( p=0.035p=0.035 ), and the 4 in . thick HMA test item was found to be the better performer. 同样,如果直接比较相同 CBR 值基层的 HMA 厚度,可以发现对于 6 CBR 基层,增加 HMA 厚度并不会导致平均基底顶压力出现显著的统计学差异( p=0.508p=0.508 )。对 10 CBR 路基进行比较后发现,在统计意义上( p=0.035p=0.035 ),4 英寸厚的 HMA 试验项目表现更好。
Table 13. Statistical analysis of top of base pressure response. 表 13.底座顶部压力响应的统计分析。
Comparison n p-Value Significant Better Performer Difference (psi) ^(1)
4HMA, GR, 10 CBR vs. 2HMA, GR, 10 CBR 5 0.559 No Same 0.0
4HMA, GR, 10 CBR vs. 4HMA, LS, 6 CBR 28 0.003 Yes 4HMA, LS, 6 CBR -17.8
4HMA, GR, 10 CBR vs. 2HMA, LS, 6 CBR 28 0.008 Yes 2HMA, LS, 6 CBR -20.0
4HMA, GR, 10 CBR vs. 4HMA, LS, 10 CBR 28 <0.001 Yes 4HMA, LS, 10 CBR -25.1
4HMA, GR, 10 CBR vs. 2HMA, LS, 10 CBR 28 0.002 Yes 2HMA, LS, 10 CBR -27.2
2HMA, GR, 10 CBR vs. 4HMA, LS, 6 CBR 5 0.287 No Same 0.0
2HMA, GR, 10 CBR vs. 2HMA, LS, 6 CBR 5 0.192 No Same 0.0
2HMA, GR, 10 CBR vs. 4HMA, LS, 10 CBR 5 0.224 No Same 0.0
2HMA, GR, 10 CBR vs. 2HMA, LS, 10 CBR 5 0.176 No Same 0.0
4HMA, LS, 6 CBR vs. 2HMA, LS, 6 CBR 34 0.508 No Same 0.0
4HMA, LS, 6 CBR vs. 4HMA, LS, 10 CBR 37 0.236 No Same 0.0
4HMA, LS, 6 CBR vs. 2HMA, LS, 10 CBR 37 0.643 No Same 0.0
2HMA, LS, 6 CBR vs. 4HMA, LS, 10 CBR 34 0.016 Yes 4HMA, LS, 10 CBR -10.6
2HMA, LS, 6 CBR vs. 2HMA, LS, 10 CBR 34 0.020 Yes 2HMA, LS, 10 CBR -4.9
4HMA, LS, 10 CBR vs. 2HMA, LS, 10 CBR 38 0.035 Yes 4HMA, LS, 10 CBR -12.7| Comparison | $n$ | $p$-Value | Significant | Better Performer | Difference (psi) ${ }^{1}$ |
| :---: | :---: | :---: | :---: | :---: | :---: |
| 4HMA, GR, 10 CBR vs. 2HMA, GR, 10 CBR | 5 | 0.559 | No | Same | 0.0 |
| 4HMA, GR, 10 CBR vs. 4HMA, LS, 6 CBR | 28 | 0.003 | Yes | 4HMA, LS, 6 CBR | -17.8 |
| 4HMA, GR, 10 CBR vs. 2HMA, LS, 6 CBR | 28 | 0.008 | Yes | 2HMA, LS, 6 CBR | -20.0 |
| 4HMA, GR, 10 CBR vs. 4HMA, LS, 10 CBR | 28 | <0.001 | Yes | 4HMA, LS, 10 CBR | -25.1 |
| 4HMA, GR, 10 CBR vs. 2HMA, LS, 10 CBR | 28 | 0.002 | Yes | 2HMA, LS, 10 CBR | -27.2 |
| 2HMA, GR, 10 CBR vs. 4HMA, LS, 6 CBR | 5 | 0.287 | No | Same | 0.0 |
| 2HMA, GR, 10 CBR vs. 2HMA, LS, 6 CBR | 5 | 0.192 | No | Same | 0.0 |
| 2HMA, GR, 10 CBR vs. 4HMA, LS, 10 CBR | 5 | 0.224 | No | Same | 0.0 |
| 2HMA, GR, 10 CBR vs. 2HMA, LS, 10 CBR | 5 | 0.176 | No | Same | 0.0 |
| 4HMA, LS, 6 CBR vs. 2HMA, LS, 6 CBR | 34 | 0.508 | No | Same | 0.0 |
| 4HMA, LS, 6 CBR vs. 4HMA, LS, 10 CBR | 37 | 0.236 | No | Same | 0.0 |
| 4HMA, LS, 6 CBR vs. 2HMA, LS, 10 CBR | 37 | 0.643 | No | Same | 0.0 |
| 2HMA, LS, 6 CBR vs. 4HMA, LS, 10 CBR | 34 | 0.016 | Yes | 4HMA, LS, 10 CBR | -10.6 |
| 2HMA, LS, 6 CBR vs. 2HMA, LS, 10 CBR | 34 | 0.020 | Yes | 2HMA, LS, 10 CBR | -4.9 |
| 4HMA, LS, 10 CBR vs. 2HMA, LS, 10 CBR | 38 | 0.035 | Yes | 4HMA, LS, 10 CBR | -12.7 |
^(1){ }^{1} Average difference between datasets; n=n= number of observations. ^(1){ }^{1} 数据集之间的平均差; n=n= 观测值的数量。
Measured base pressure response at middepth of the base layer is presented in Figure 70. The lowest middepth pressure response was observed in the 4 in. 图 70 显示了测量到的基底层中间深度的基底压力响应。中深层压力响应最低的是 4 英寸(2.5 米)的地层。 thick HMA over LS base over 10 CBR subgrade test item, and the highest measured middepth pressure response was observed in the companion 2 in. thick HMA test item. In general, measured middepth base layer pressures ranged from 60 psi to 120 psi . 在 10 CBR 基层测试项目中,在 LS 基层上的 HMA 厚度最大,而在配套的 2 英寸厚 HMA 测试项目中,测得的中深层压力响应最高。一般来说,测得的基层中深层压力介于 60 psi 到 120 psi 之间。 A slight increasing trend was observed in most cases suggesting that damage was occurring in the base course layer with an increase in traffic passes. 在大多数情况下,都观察到了轻微的增加趋势,这表明随着通行次数的增加,基底层出现了损坏。
Figure 70. Measured middepth base pressure response with traffic. 图 70.交通情况下测量的中深基底压力响应。
Equality plots for middepth base pressure measurements are presented in Figure 71 through Figure 74. A review of Figures 71 and 72 revealed that measured response data fell below the LOE, indicating that measured pressures were greater in the 2 in. 图 71 至图 74 显示了中间深度基底压力测量的等值图。图 71 和图 72 显示,测得的响应数据低于 LOE,这表明在 2 英寸和 2 英寸以下区域测得的压力更大。 thick HMA test items. The measured data tended to be further from the LOE in the case of a 10 CBR subgrade. A review of the 4 in. 厚 HMA 测试项目。对于 CBR 值为 10 的基层,测量数据往往与 LOE 相差较远。对 4 in. thick HMA equality plot (Figure 73) found that all measured data fell above the LOE, indicating that a reduction in subgrade CBR resulted in an increase in middepth base pressure. Measured pressures in the 2 in. 厚 HMA 等值图(图 73)发现,所有测量数据都高于 LOE,表明基层 CBR 的降低导致中深层基底压力的增加。在 2 in. thick HMA test items (Figure 74) fell both above and below the LOE suggesting that subgrade CBR had did not have a meaningful impact on middepth base pressure response in the thinner HMA test items. 较厚的 HMA 试验项目(图 74)既高于也低于 LOE,这表明在较薄的 HMA 试验项目中,基层 CBR 对中深层基底压力响应的影响不大。
Figure 71. Middepth base pressure-effect of HMA thickness for LS base, 6 CBR subgrade. 图 71.LS 基底、6 CBR 基层的中深基面压力对 HMA 厚度的影响。
Figure 72. Middepth base pressure-effect of HMA thickness for LS base, 10 CBR subgrade. 图 72.LS 基底、10 CBR 基层的中深基面压力对 HMA 厚度的影响。
Figure 73. Middepth base pressure-effect of subgrade CBR for 4 in. HMA, LS base. 图 73.4 英寸 HMA、LS 基底的中深层基底压力对基底 CBR 的影响。
Figure 74. Middepth base pressure-effect of subgrade CBR for 2 in . HMA, LS base. 图 74.2 英寸 HMA、LS 基底的中深层基底压力对基底 CBR 的影响。
A summary of a statistical analysis of middepth base pressure response is presented in Table 14. A comparison of subgrade strength found that differences in average middepth base pressure response were not statistically significant in the 2 in. thick HMA, LS test items ( p=0.106p=0.106 ) but were significant in the 4 in . thick HMA, LS test items ( p < 0.001p<0.001 ). In the 4 in. hick HMA, LS test items, the comparison indicated that the item constructed on a 10 CBR subgrade had a lower average middepth pressure response than the item constructed on a 6 CBR subgrade. 中深层路基压力响应的统计分析摘要见表 14。通过比较路基强度发现,在 2 英寸厚 HMA、LS 测试项目( p=0.106p=0.106 )中,平均中深基底压力响应的差异在统计上并不显著,但在 4 英寸厚 HMA、LS 测试项目( p < 0.001p<0.001 )中,差异显著。在 4 英寸厚 HMA LS 测试项目中,比较结果表明,在 10 CBR 基层上施工的项目的平均中深压力响应低于在 6 CBR 基层上施工的项目。
Direct comparison of HMA thickness on a 6 CBR subgrade, LS base was found to be statistically significant ( p=0.001p=0.001 ), and the 4 in . thick test item was the better performer. Similarly, comparison of HMA thickness on a 10 CBR subgrade, LS base was statistically significant ( p < 0.001p<0.001 ), and the 4 in . thick test item was the better performer. These comparisons suggest that an increase in HMA thickness resulted in an improvement in middepth base pressure response. 在 6 CBR 路基、LS 路基上直接比较 HMA 厚度,发现统计意义显著( p=0.001p=0.001 ),4 英寸厚的测试项目性能更好。同样,在 10 CBR 路基、LS 路基上比较 HMA 厚度也有统计学意义( p < 0.001p<0.001 ),4 英寸厚的测试项目性能更好。这些比较表明,增加 HMA 厚度可改善中深层路基压力响应。 It was noted that the average difference in measured response with an increase in HMA thickness was much greater in the 10 CBR subgrade than the 6 CBR subgrade (i.e., 30.4 psi vs. 6.0 psi ), suggesting that middepth pressure was sensitive to changes in subgrade strength. 我们注意到,随着 HMA 厚度的增加,10 CBR 基层与 6 CBR 基层在测量响应上的平均差异要大得多(即 30.4 psi 与 6.0 psi),这表明中间深度压力对基层强度的变化非常敏感。
Table 14. Statistical comparison of middepth pressure response. 表 14.中深度压力响应的统计比较。
^(1){ }^{1} Average difference between datasets; n=n= number of observations. ^(1){ }^{1} 数据集之间的平均差; n=n= 观测值的数量。
8.2.5 SDD Response 8.2.5 SDD 响应
SDD response data are presented in Figure 75. These data represent the peak dynamic vertical deflection response under traffic and were determined by subtracting the local minimum and maximum value for each event. SDD 响应数据见图 75。这些数据代表了交通状况下的峰值动态垂直变形响应,是通过减去每个事件的局部最小值和最大值确定的。 Steadystate subgrade dynamic deflections in the limestone base test items ranged generally from 0.15 in . to 0.30 in . In the case of the gravel base test items, dynamic subgrade deflection peaked at approximately 0.40 in . 石灰岩路基测试项目的稳态路基动态挠度范围一般在 0.15 英寸至 0.30 英寸之间。 在砾石路基测试项目中,路基动态挠度峰值约为 0.40 英寸。
Equality plots for dynamic SDD response measurements are presented in Figure 76 through Figure 78. Figure 76 indicates that dynamic deflections tended to be greater in the 2 in. thick HMA test item than the 4 in. thick HMA test item on 6 CBR subgrade. 动态 SDD 响应测量的等值图见图 76 至图 78。图 76 显示,在 6 CBR 路基上,2 英寸厚 HMA 试验项目的动态挠度往往大于 4 英寸厚 HMA 试验项目。 A review of Figure 77 indicated that the measured data tended to fall along the LOE early in traffic but departed from the LOE later in traffic suggesting that HMA thickness did not have meaningful effect on dynamic subgrade deflection on a firmer subgrade until later in traffic application. 图 77 显示,测量数据往往在交通早期沿 LOE 分布,但在交通后期偏离 LOE,这表明 HMA 厚度在交通应用后期才会对较坚实路基的动态路基挠度产生有意义的影响。
Figures 78 and 79 can be used to investigate the effect of subgrade CBR on measured dynamic subgrade deflection. 图 78 和 79 可用于研究路基 CBR 对测量的路基动态挠度的影响。 In both cases the data fell mostly above the LOE indicating that greater dynamic deflections were measured in the softer subgrade CBR test items regardless of HMA thickness. 在这两种情况下,大部分数据都高于 LOE,表明无论 HMA 厚度如何,在较松软的基层 CBR 试验项目中测得的动态挠度更大。
Figure 75. Dynamic subgrade deflection with traffic. 图 75.交通情况下的动态路基挠度。
Figure 76. Dynamic deflection-effect of HMA thickness for LS base, 6 CBR subgrade. 图 76.LS 基层、6 CBR 基层的动态挠度对 HMA 厚度的影响。
Figure 77. Dynamic deflection-effect of HMA thickness for LS base, 10 CBR subgrade. 图 77.LS 基底、10 CBR 基层的动态挠度对 HMA 厚度的影响。
Figure 78. Dynamic deflection-effect of subgrade CBR for 4 in. HMA, LS base. 图 78.4 英寸 HMA、LS 基层的动态挠度对基层 CBR 的影响。
Figure 79. Dynamic deflection-effect of subgrade CBR for 2 in. HMA, LS base. 图 79.2 英寸 HMA、LS 基层的动态挠度对基层 CBR 的影响。
A statistical comparison of dynamic subgrade deflection response is presented in Table 15. Statistically significant differences in dynamic response were observed in terms of subgrade strength for both HMA thicknesses. In the case of both the 2 in. 表 15 列出了路基动态挠度响应的统计比较。两种 HMA 厚度的路基强度在动态响应方面存在明显的统计学差异。在 2 英寸和 2 英寸 HMA 厚度的情况下,路基挠度响应的统计比较结果如表 15 所示。 thick HMA over LS base test items and the 4 in. thick HMA over LS base test items, researchers observed that average dynamic subgrade deflection was less in the 10 CBR subgrade test item. 研究人员观察到,在 10 CBR 基层试验项目中,LS 基层上的厚 HMA 试验项目和 LS 基层上的 4 英寸厚 HMA 试验项目的基层平均动态挠度较小。
A comparison of HMA thickness on the 6 CBR subgrade found that an increase in thickness resulted in a statistically significant improvement ( p < 0.001p<0.001 ) in average dynamic subgrade deflection. Similar observations were made on the 10 CBR subgrade. Thus, it can be concluded that an increase in HMA thickness resulted in an improvement in dynamic subgrade deflection. 对 6 CBR 路基上的 HMA 厚度进行比较后发现,增加厚度可显著改善路基平均动态挠度( p < 0.001p<0.001 )。在 10 CBR 路基上也有类似的观察结果。因此,可以得出结论:增加 HMA 厚度可改善路基动态挠度。
^(1){ }^{1} Average difference between datasets; n=n= number of observations. ^(1){ }^{1} 数据集之间的平均差; n=n= 观测值的数量。
Accumulated (permanent) SDD measurements are presented in Figure 80. These data were determined by recording the baseline SDD response prior to each pass of the HVS and then recording the baseline after each pass of the HVS. 累积(永久)SDD 测量值见图 80。这些数据是在每次通过 HVS 之前记录 SDD 响应基线,然后在每次通过 HVS 之后记录基线而得出的。 Thus, the data represent cumulative deflection near the top of the subgrade. In general, the data followed expected trends; permanent deformation tended to increase as the test gear moved closer to the SDD. 因此,这些数据表示的是基层顶部附近的累积变形。总体而言,数据符合预期趋势;当测试装置靠近 SDD 时,永久变形趋于增加。 Measurement early in traffic indicated that the highest permanent subgrade deflection was measured in the 2HMA over GR over 10 CBR test item as expected. Permanent deflection measured near the top of the subgrade at the end of traffic ranged from approximately 0.6 in. 交通初期的测量结果表明,2HMA 超过 GR 超过 10 CBR 测试项目的路基永久挠度最高。在交通结束时,在路基顶部附近测得的永久挠度范围约为 0.6 英寸(0.5 毫米)。 to 1.0 in . 至 1.0 英寸 .
Equality plots to investigate the effect of HMA thickness of permanent subgrade deflection are presented in Figures 81 and 82. In both cases early measurements tended to fall above the LOE indicating that greater permanent subgrade deflection was measured in the 4 in. 图 81 和图 82 显示了研究 HMA 厚度对永久性路基挠度影响的等值图。在这两种情况下,早期测量结果都倾向于落在 LOE 以上,这表明在 4 英寸 HMA 厚度下测量到的永久路基挠度更大。 thick HMA test items. Later in traffic application the data trend below the LOE indicating that greater permanent deflections were measured in the 2 in. thick HMA test items. 厚的 HMA 试验项目。在交通应用的后期,数据趋势低于 LOE,表明在 2 英寸厚的 HMA 测试项目中测得了更大的永久挠度。
Figures 83 and 84 can be used to investigate the effect of subgrade CBR for each HMA thickness. In both cases the data plotted well above the LOE, indicating that greater deflections were measured in the 6 CBR subgrade test items when compared to the 10 CBR subgrade test items. 图 83 和图 84 可用于研究每种 HMA 厚度的基层 CBR 的影响。在这两种情况下,绘制的数据都远高于 LOE,表明与 10 CBR 路基测试项目相比,6 CBR 路基测试项目测得的挠度更大。
Figure 80. Permanent subgrade deflection with traffic. 图 80.交通量导致的路基永久变形。
Figure 81. Permanent deflection-effect of HMA thickness for LS base, 6 CBR subgrade. 图 81.LS 基底、6 CBR 基层的永久挠度对 HMA 厚度的影响。
Figure 82. Permanent deflection-effect of HMA thickness for LS base, 10 CBR subgrade. 图 82.LS 基底、10 CBR 基层的永久挠度对 HMA 厚度的影响。
Figure 83. Permanent deflection-effect of subgrade CBR for 4 in. HMA, LS base. 图 83.4 英寸 HMA、LS 基层的永久挠度对基层 CBR 的影响。
Figure 84. Permanent deflection-effect of subgrade CBR for 2in2 \mathrm{in}. HMA, LS base. 图 84. 2in2 \mathrm{in} . HMA、LS 基层的永久挠度对基层 CBR 的影响。
A statistical analysis of permanent subgrade deflection response is presented in Table 16. A comparison of subgrade strength on the 2 in. thick HMA over LS base test items was found to be statistically significant ( p < 0.001p<0.001 ), and the 10 CBR subgrade test item was found to be the better performer. Additionally, a comparison of subgrade strength on the 4 in . thick HMA over LS base test items was found to be statistically significant ( p < 0.001p<0.001 ), and the 10 CBR subgrade test item was found to be the better performer. Thus, an increase in subgrade strength resulted in an improvement in average permanent subgrade deflection response. 表 16 列出了对永久性路基挠度响应的统计分析。通过比较 2 英寸厚 HMA 加 LS 基底测试项目的路基强度,发现在统计意义上( p < 0.001p<0.001 ),10 CBR 路基测试项目的表现更好。此外,对 4 英寸厚 HMA 碾压 LS 基层测试项目的基层强度进行比较后发现,在统计意义上( p < 0.001p<0.001 ),10 CBR 基层测试项目的性能更好。因此,提高路基强度可改善路基平均永久挠度响应。
The comparisons of HMA thickness over LS base, on both a 6 and 10 CBR subgrade were unremarkable ( p=0.072p=0.072 and p=0.216p=0.216, respectively) indicating that an increase in HMA thickness did not have a statistically significant effect on average permanent subgrade deflection. 在 CBR 值为 6 和 10 的路基上,HMA 厚度与 LS 厚度的比较结果均无明显差异(分别为 p=0.072p=0.072 和 p=0.216p=0.216 ),这表明增加 HMA 厚度对路基平均永久挠度没有显著的统计学影响。
Table 16. Statistical comparison of permanent subgrade deflection. 表 16.永久性路基挠度的统计比较。
^(1){ }^{1} Average difference between datasets; n=n= number of observations. ^(1){ }^{1} 数据集之间的平均差; n=n= 观测值的数量。
8.2.6 ASG Response 8.2.6 助理秘书长答复
Longitudinal ASG response data are presented in Figure 85. Like other instrumentation response data, an increase in response was observed as the test gear transitioned from being centered on the traffic lane to receiving a direct hit from a test wheel. 纵向 ASG 响应数据见图 85。与其他仪表响应数据一样,当测试齿轮从位于行车道中心过渡到受到测试车轮的直接撞击时,也观察到了响应的增加。 For longer-term trafficking, an increase in HMA strain was observed with an increase in traffic application. This was expected because the HMA layer continued to deform under increased traffic. 在长期交通中,随着交通量的增加,观察到 HMA 应变增加。这在意料之中,因为在交通量增加的情况下,HMA 层会继续变形。 In the limestone base layer items, the highest longitudinal HMA strain was measured in the 2HMA over 6 CBR subgrade test item as expected. The least longitudinal strain was observed in the 4HMA over 10 在石灰岩基层项目中,2HMA 超过 6 CBR 基层测试项目测得的 HMA 纵向应变最大,这在意料之中。纵向应变最小的是 4HMA 超过 10
CBR subgrade test item, which was the stiffest overall item. The longitudinal strain gauge installed in the 4HMA over LS over 6 CBR test item failed after HMA paving; thus, data were not collected for this gauge. CBR 基层测试项目是整体硬度最高的项目。在 4HMA over LS over 6 CBR 测试项目中安装的纵向应变仪在 HMA 摊铺后失效,因此没有收集该应变仪的数据。
Figure 86 shows that the data fell mostly along the LOE suggesting that HMA thickness had little influence on measured longitudinal HMA strain on a stronger subgrade. The effect of subgrade CBR on longitudinal HMA strain for the 2 in. 图 86 显示,数据主要沿着 LOE 分布,表明 HMA 厚度对较坚固基层上测得的 HMA 纵向应变影响不大。对于 2 英寸 HMA 路面,基层 CBR 对纵向应变的影响如图 86 所示。 thick HMA test items can be observed in Figure 87. The data generally plotted above the LOE indicating that greater longitudinal HMA strain was measured in the 6 CBR subgrade test item. 从图 87 中可以观察到厚 HMA 试验项目的纵向应变。数据一般绘制在 LOE 以上,表明在 6 CBR 基层测试项目中测得的 HMA 纵向应变更大。
Figure 85. Longitudinal ASG response with traffic. 图 85.ASG 随车流的纵向响应。
Figure 86. Longitudinal strain-effect of HMA thickness for LS base, 10 CBR subgrade. 图 86.LS 基层、10 CBR 基层的纵向应变对 HMA 厚度的影响。
Figure 87. Longitudinal strain-effect of subgrade CBR for 2in2 \mathrm{in}. HMA, LS base. 图 87. 2in2 \mathrm{in} . HMA、LS 基层的路基 CBR 纵向应变效应。
A statistical comparison of longitudinal ASG response is summarized in Table 17. For the 2 in. thick HMA over LS base test items, the team found that the 10 CBR subgrade resulted in a statistically significant ( p < 0.001p<0.001 ) improvement in average longitudinal HMA strain. No data were available for the 4 in. thick HMA, LS base test item due to a gauge malfunction. 表 17 总结了纵向 ASG 响应的统计比较。对于 2 英寸厚的 HMA 和 LS 基层测试项目,研究小组发现 10 CBR 基层可显著改善 HMA 平均纵向应变( p < 0.001p<0.001 )。由于测量仪故障,4 英寸厚 HMA、LS 基层测试项目没有数据。
Similarly, data were not available to make statistical inferences on the effect of HMA thickness on a 6 CBR subgrade. On a 10 CBR subgrade, it was found that differences between 2 in . and 4 in . of HMA were not statistically significant ( p=0.195p=0.195 ). 同样,在 6 CBR 路基上,HMA 厚度的影响也无法通过数据进行统计推断。在 10 CBR 路基上,发现 2 英寸和 4 英寸 HMA 之间的差异在统计学上并不显著( p=0.195p=0.195 )。
A summary of transverse ASG measurements is presented in Figure 88. These data showed similar trends to those observed in the longitudinal strain gauge measurements. The highest strain was observed in the 2 in . 图 88 显示了横向 ASG 测量的概要。这些数据显示了与纵向应变片测量结果类似的趋势。最高应变出现在 2 in . thick HMA, LS, 6 CBR test item and the lowest strain was observed in the 4 in. thick HMA, LS, 10 CBR test item. An increasing trend was observed in all test data with an increase in traffic passes, corresponding to an increase in deformation in the HMA layer. 厚 HMA、LS、6 CBR 测试项目的应变最小,4 英寸厚 HMA、LS、10 CBR 测试项目的应变最小。随着交通流量的增加,所有测试数据都呈上升趋势,这与 HMA 层变形的增加相对应。
Figures 89 and 90 present equality plots to investigate the effect of HMA thickness for the 6 CBR subgrade and 10 CBR subgrade, respectively. For the 6 CBR subgrade, the data plotted below the LOE, indicating that greater transverse strains were measured in the 2 in . 图 89 和图 90 分别显示了 6 CBR 路基和 10 CBR 路基的等值图,以研究 HMA 厚度的影响。对于 6 CBR 路基,绘制的数据低于 LOE,表明在 2 in . thick HMA test item. For the 10 CBR subgrade, the data tended to plot along the LOE early in traffic but diverged from the LOE later in traffic (greater strain values). 厚 HMA 测试项目。对于 CBR 值为 10 的基层,在交通初期,数据倾向于沿着 LOE 绘制,但在交通后期则偏离 LOE(应变值较大)。 These data suggest that HMA thickness is more influential on measured strain at lower subgrade CBR values where the overall pavement movement under load is higher. These observations are confirmed in Figures 91 and 92 where the 4 in. 这些数据表明,在路基 CBR 值较低时,HMA 厚度对测量应变的影响更大,因为此时路面在荷载作用下的整体移动量更大。这些观察结果在图 91 和图 92 中得到了证实。 thick HMA equality plot (Figure 91) shows the data falling both above and below the LOE and the 2 in. thick HMA equality plot (Figure 92) shows the data falling entirely above the LOE. 厚 HMA 等值图(图 91)显示数据既高于也低于 LOE,而 2 英寸厚 HMA 等值图(图 92)显示数据完全高于 LOE。
Figure 89. Transverse strain-effect of HMA thickness for LS base, 6 CBR subgrade. 图 89.LS 基层、6 CBR 基层的横向应变对 HMA 厚度的影响。
Figure 90. Transverse strain-effect of HMA thickness for LS base, 10 CBR subgrade. 图 90.LS 基层、10 CBR 基层的横向应变对 HMA 厚度的影响。
Figure 91. Transverse strain-effect of subgrade CBR for 4 in. HMA, LS base. 图 91.4 英寸 HMA、LS 基层的横向应变对基层 CBR 的影响。
Figure 92. Transverse strain-effect of subgrade CBR for 2 in. HMA, LS base. 图 92.2 英寸 HMA、LS 基层的横向应变对基层 CBR 的影响。
A statistical analysis of transverse ASG response is presented in Table 18. A comparison of subgrade strength on the 2 in. thick HMA, LS base test items was found to be statistically significant ( p < 0.001p<0.001 ), and research found that less average transverse HMA strain was measured in the 10 CBR subgrade test item. Similar results were observed in the 4 in . thick HMA, LS base test items. 表 18 列出了横向 ASG 响应的统计分析。2 英寸厚 HMA、LS 基层测试项目的基层强度比较具有统计学意义( p < 0.001p<0.001 ),研究发现在 10 CBR 基层测试项目中测得的 HMA 平均横向应变较小。在 4 英寸厚的 HMA、LS 基层测试项目中也观察到了类似的结果。
A comparison of HMA thickness found that a statistically significant difference ( p=0.004p=0.004 ) was observed on a 6 CBR subgrade, and the 4 in. thick HMA test item was found to be the better performer. A comparison of HMA thickness on a 10 CBR subgrade was found to be unremarkable ( p=0.942p=0.942 ), suggesting that an increase in HMA thickness did not have a significant effect on average transverse strain in the case of a stiffer subgrade for the modest increase in HMA thickness evaluated in this study. 对 HMA 厚度进行比较后发现,在 6 CBR 路基上观察到的差异( p=0.004p=0.004 )具有统计学意义,4 英寸厚的 HMA 测试项目表现更好。在 10 CBR 路基上进行的 HMA 厚度比较没有发现明显差异( p=0.942p=0.942 ),这表明在本研究中评估的 HMA 厚度适度增加的情况下,增加 HMA 厚度对较硬路基的平均横向应变没有明显影响。
^(1){ }^{1} Average difference between datasets; n=n= number of observations. ^(1){ }^{1} 数据集之间的平均差; n=n= 观测值的数量。
9 Results: ADR Capabilities 9 结果:替代性争议解决能力
ADR techniques were evaluated to determine compatibility with the P-8\mathrm{P}-8 aircraft. The ERDC has a long history of evaluating various airfield damage repair techniques and procedures, and several technical reports are available that provide generous details of each repair technique (Carruth 2020; Bell et al. 2019; Bell et al. in draft ^(1){ }^{1} ). For the purposes of this report, a brief construction description is provided for each repair technique. All simulated craters were constructed and trafficked in Lane 1 (consisting of 14 in. thick PCC) for the evaluation. 对 ADR 技术进行了评估,以确定与 P-8\mathrm{P}-8 飞机的兼容性。ERDC 长期以来一直在评估各种机场损伤修复技术和程序,目前已有多份技术报告详细介绍了每种修复技术(Carruth 2020;Bell 等人,2019;Bell 等人,草稿中 ^(1){ }^{1} )。在本报告中,我们将简要介绍每种修复技术的构造。所有模拟坑道均在 1 号车道(由 14 英寸厚的 PCC 组成)上施工和行车,以进行评估。 Two simulated craters were repaired and trafficked simultaneously. The crater repair techniques were paired to achieve similar passes to failure to increase testing efficiency. 两个模拟弹坑同时进行修复和通行。凹坑修复技术配对使用,以达到相似的失效通过率,从而提高测试效率。 Results of construction quality control tests (when applicable) and traffic testing are presented in the following subsections. Due to the time sensitive nature of several of the repair techniques, detailed quality control data were not collected. 施工质量控制测试(如适用)和交通测试的结果见下文各小节。由于一些维修技术具有时间敏感性,因此没有收集详细的质量控制数据。
Repair 1 consisted of a geosynthetic reinforced sand backfill surfaced with a fiberglass reinforced polymer (FRP) foreign object debris cover. A simulated crater was excavated to a depth of 18 in., and the bottom of the excavation was leveled and recompacted. A 6-oz/yd ^(2){ }^{2}, nonwoven geotextile was placed in the bottom of the excavation. An approximate 4 in. thick compacted sand layer was placed over the geotextile. Another geotextile was placed on the compacted sand layer, and a biaxial geogrid was placed directly on the geotextile. 修复 1 包括土工合成材料加固的沙土回填,表面覆盖玻璃纤维增强聚合物 (FRP) 异物碎屑。一个模拟弹坑被挖掘到 18 英寸深,挖掘底部被整平并重新压实。在挖掘底部铺设了 6 盎司/yd ^(2){ }^{2} 的无纺土工织物。在土工织物上铺上大约 4 英寸厚的压实砂层。在压实的砂层上再铺上一层土工织物,然后在土工织物上直接铺上双轴土工格栅。 Thereafter, an approximate 4 in. thick compacted sand layer was placed over the geotextile/geogrid combination. This process was repeated until the simulated crater was filled. 然后,在土工织物/土工格栅组合上铺上大约 4 英寸厚的压实砂层。重复这一过程,直到填满模拟坑。 The FRP FOD cover was placed over the completed reinforced sand backfill layer and secured to the surrounding concrete slabs. Geosynthetic properties are summarized in Table 19. 玻璃钢 FOD 覆盖层被放置在已完成的加固砂回填层上,并固定在周围的混凝土板上。表 19 概述了土工合成材料的特性。
Nuclear density gauge measurements were made on each compacted lift of sand to measure construction uniformity. Measurements were made in the center of the crater, near the side of the crater, and near a corner of the crater. The average wet density and standard deviation was 102.5+-1.8102.5 \pm 1.8 pcf, average dry density was 98.2+-2.0pcf98.2 \pm 2.0 \mathrm{pcf}, and average moisture content was 4.4+-0.8%4.4 \pm 0.8 \%. In general, the construction density measurements indicated that the sand backfill was uniformly constructed, and that material variability was within expected ranges for small-scale construction efforts. 对每次压实的沙堆都进行了核密度计测量,以衡量施工的均匀性。测量分别在陨石坑中心、靠近陨石坑一侧和靠近陨石坑一角进行。平均湿密度和标准偏差为 102.5+-1.8102.5 \pm 1.8 pcf,平均干密度为 98.2+-2.0pcf98.2 \pm 2.0 \mathrm{pcf} ,平均含水量为 4.4+-0.8%4.4 \pm 0.8 \% 。总体而言,施工密度测定结果表明,沙土回填施工均匀,材料变化在小规模施工的预期范围内。
Traffic was applied using the P-8 aircraft gear load configuration and wander pattern described in Chapter 7. Failure of the repair technique was considered to be 1.5 in . of permanent deformation (sag) in the FRP panel measured in a loaded condition. 使用第 7 章中描述的 P-8 飞机齿轮负载配置和游动模式进行交通。在加载条件下测量的玻璃钢面板永久变形(下垂)达到 1.5 英寸时,修复技术即告失败。 FRP tends to possess a meaningful amount of rebound; therefore, the mat was lightly loaded during elevation measurements to ensure that it was in contact with the underlying soils. A hydraulic pump and load piston were used to apply a seating load to the mat. 玻璃钢往往具有一定的回弹力;因此,在测量标高时,对垫子进行轻载,以确保垫子与下层土壤接触。使用液压泵和负载活塞对垫子施加固定负载。 The system consisted of a T-shaped I-beam that mounted on the hydraulic piston. The T-shaped beam was situated to contact the HVS carriage beam that provided a reaction force. A hydraulic pump was used to extend the piston and place approximately 2,000lbf2,000 \mathrm{lbf} total seating load on the FRP panel consistent with historical experiments. 该系统由安装在液压活塞上的 T 形工字梁组成。T 形梁的位置与提供反作用力的 HVS 支架梁相接触。液压泵用于延长活塞,并在 FRP 面板上施加大约 2,000lbf2,000 \mathrm{lbf} 的总座荷载,这与以往的实验一致。
Results of loaded deformation for geosynthetic reinforced sand with FRP are provided in Figure 93. Permanent deformation was measured using rod and level, and rut depth was measured using a straightedge and machined depth wedge. 图 93 提供了玻璃钢土工合成材料加固砂的加载变形结果。永久变形是用杆和水平仪测量的,车辙深度是用直尺和加工好的深度楔测量的。 A relatively linear increase in deformation was observed with an increase in traffic. The geosynthetic reinforced backfill surfaced with FRP sustained approximately 50 passes of the 随着交通量的增加,变形量也出现了相对线性的增加。用玻璃钢铺设的土工合成材料加固的回填土承受了大约 50 次的车流冲击。
P-8 gear before reaching the 1.5 in . failure criteria. No mat breakage and/or cracking was observed prior to failure. Photographs of the loaded FRP at the conclusion of traffic are shown in Figure 94. P-8 齿轮在达到 1.5 英寸失效标准之前。在失效前未观察到垫层断裂和/或开裂。图 94 显示了交通结束时加载 FRP 的照片。
Figure 93. Permanent deformation of geosynthetic reinforced sand with FRP. 图 93.使用玻璃钢的土工合成材料加固砂的永久变形。
Figure 94. Photographs of geogrid stabilized backfill-posttraffic. 图 94.土工格栅加固后回填土的照片。
9.2 Repair 2: Crushed Limestone with FRP 9.2 修复 2:碎石灰石加玻璃钢
Repair 2 consisted of a crushed limestone aggregate backfill surfaced with an FRP FOD cover. A simulated crater was excavated to a depth of 18 in., and the bottom of the excavation was leveled and recompacted. The crushed limestone backfill was placed in approximately 4 in. 修复 2 包括碎石灰石骨料回填,表面覆盖玻璃钢 FOD 覆盖层。一个模拟弹坑被挖掘到 18 英寸深,挖掘底部被整平并重新压实。碾碎的石灰岩回填土被放置在约 4 英寸深的土层中。 thick compacted lifts 厚压实升降机
until reaching the existing surface elevation of the surrounding concrete slabs. An FRP FOD cover was placed over the completed crushed limestone backfill layer and secured to the surrounding concrete slabs. 直到达到周围混凝土板的现有表面高程。在已完成的碎石灰岩回填层上放置了玻璃钢 FOD 覆盖层,并将其固定在周围的混凝土板上。
Nuclear density gauge measurements were made on each completed limestone aggregate backfill layer. Measurements were made in the center of the crater, near the side of the crater, and near a corner of the crater. The average wet density and standard deviation was 138.8+-4.4138.8 \pm 4.4 pcf, average dry density was 133.8+-4.2pcf133.8 \pm 4.2 \mathrm{pcf}, and average moisture content was 3.7+-0.5%3.7 \pm 0.5 \%. The dry density was less than would be anticipated in full-scale construction efforts; however, compaction was achieved with a small walk-behind vibratory plate compactor, and less compaction energy was available. 对每个完成的石灰岩集料回填层进行了核密度计测量。测量分别在陨石坑中心、靠近陨石坑一侧和靠近陨石坑一角进行。平均湿密度和标准偏差为 138.8+-4.4138.8 \pm 4.4 pcf,平均干密度为 133.8+-4.2pcf133.8 \pm 4.2 \mathrm{pcf} ,平均含水量为 3.7+-0.5%3.7 \pm 0.5 \% 。干密度小于全面施工的预期值;不过,压实是用一台小型步行式振动平板压实机完成的,压实能量较小。
Results of loaded deformation for crushed limestone backfill with FRP are provided in Figure 95. Permanent deformation was measured using rod and level, and rut depth was measured using a straightedge and machined depth wedge. 图 95 提供了采用玻璃钢的碎石灰岩回填土的加载变形结果。永久变形是用杆和水平仪测量的,车辙深度是用直尺和加工好的深度楔测量的。 The crushed limestone repair technique sustained approximately 600 passes of the P-8 test gear before reaching the 1.5 in. failure criteria. No mat breakage and/or cracking was observed prior to failure. 在达到 1.5 英寸的失效标准之前,碎石灰岩修复技术在 P-8 试验齿轮上承受了大约 600 次的测试。在失效前未观察到垫层断裂和/或开裂。 Photographs of the loaded FRP at the conclusion of traffic are shown in Figure 96. 图 96 显示了交通结束时加载的玻璃纤维增强塑料的照片。
Figure 95. Permanent deformation of crushed limestone backfill with FRP. 图 95.采用玻璃钢的碎石灰石回填土的永久变形。
Figure 96. Photographs of posttest limestone backfill. 图 96.测试后石灰岩回填土的照片。
Repair 3 consisted of a cement stabilized sand surfaced with a FRP FOD cover. A simulated crater was excavated to a depth of 16 in., and the bottom of the excavation was leveled and recompacted. Adjacent to the excavation, a sand stockpile, moisture conditioned to approximately 6-7%6-7 \%, was spread over an area approximately 10 ft wide by 20 ft long at a thickness of approximately 8 in . Ten 92.6 lb bags of cement were uniformly spread over the sand layer to target a 10%10 \% cement content. The cement was mixed into the sand using a mixer attachment on a CTL. Then, the mixture was agitated using a loader bucket on the CTL, respread, and mixed again. This process was repeated twice to ensure a uniform distribution of cement throughout the sand layer. 修复 3 包括水泥稳定砂和玻璃钢 FOD 覆盖层。一个模拟弹坑被挖掘至 16 英寸深,挖掘底部被整平并重新压实。在挖掘坑旁边,将湿度调节至约 6-7%6-7 \% 的沙堆铺设在一个宽约 10 英尺、长约 20 英尺、厚度约为 8 英寸的区域内。十袋 92.6 磅的水泥均匀地铺在砂层上,以达到 10%10 \% 水泥含量的目标。使用 CTL 上的搅拌器附件将水泥混入砂中。然后,使用 CTL 上的装载机铲斗搅拌混合物,重新摊铺并再次混合。此过程重复两次,以确保水泥在整个砂层中均匀分布。 After mixing the material was stockpiled and covered to prevent moisture loss during placement activities. 混合后的材料被堆放并覆盖,以防止在铺设过程中水分流失。
The cement-treated sand mixture was placed in the simulated crater in approximate 4 in . thick compacted lifts. Compaction consisted of four complete coverages of a jumping jack compactor over the entire repair area. 水泥处理过的沙土混合物以大约 4 英寸厚的压实高度放置在模拟弹坑中。压实工作包括在整个修补区域使用四次千斤顶压实机进行全面压实。 This process was repeated until reaching the surface of the excavation. A metal screed was used to strike off excess material. Final surface smoothness was achieved with two passes of a vibratory plate compactor. 这个过程一直重复到挖掘表面。使用金属熨平板将多余的材料熨平。最后用振动平板压实机两次压平表面。 An FRP FOD cover was placed over the completed cement stabilized backfill layer and anchored to the surrounding concrete slabs. 在已完成的水泥稳定回填层上放置了玻璃钢 FOD 覆盖层,并将其锚固在周围的混凝土板上。
Nuclear density gauge measurements were made on the compacted cementstabilized sand layers. Measurements were made in the center of the crater, near the side of the crater, and near a corner of the crater. Average wet density and standard deviation was 114.8+-2.9pcf114.8 \pm 2.9 \mathrm{pcf}, average dry density was 对压实的水泥稳定砂层进行了核密度计测量。测量分别在陨石坑中心、靠近陨石坑一侧和靠近陨石坑一角进行。平均湿密度和标准偏差为 114.8+-2.9pcf114.8 \pm 2.9 \mathrm{pcf} ,平均干密度为 114.8+-2.9pcf114.8 \pm 2.9 \mathrm{pcf} 。 110.1+-3.9pcf110.1 \pm 3.9 \mathrm{pcf}, and average moisture content was 4.3+-0.5%4.3 \pm 0.5 \%. Dry density was generally in the range that would be expected for this material type. 110.1+-3.9pcf110.1 \pm 3.9 \mathrm{pcf} ,平均含水量为 4.3+-0.5%4.3 \pm 0.5 \% 。干密度一般在这种材料的预期范围内。
Initial traffic was applied after approximately 24 hr of cure time and was continued up to 50 total passes. At this point, a hydraulic malfunction occurred on the HVS that resulted in a suspension of test traffic. 在大约 24 小时的固化时间后,开始进行最初的运输,总共运输了 50 次。此时,HVS 出现液压故障,导致测试暂停。 Traffic was restarted after diagnosing and repairing the HVS hydraulic malfunction. The total down time was approximately 33 days. Thus, the cementitious repair materials had an unloading cure time that is outside normal airfield damage repair construction operations. 在对 HVS 液压故障进行诊断和维修后,交通重新启动。总停机时间约为 33 天。因此,水泥基修复材料的卸载固化时间超出了正常的机场损坏修复施工作业。 This detail should be considered when interpreting the test results. 在解释测试结果时应考虑这一细节。
Results of loaded deformation for cement stabilized sand backfill with FRP are provided in Figure 97. Permanent deformation was measured using rod and level, and rut depth was measured using a straightedge and machined depth wedge. Little permanent deformation was observed. 图 97 提供了使用玻璃钢的水泥稳定砂回填土的加载变形结果。永久变形是用杆和水平仪测量的,车辙深度是用直尺和加工好的深度楔测量的。观察到的永久变形很小。 Traffic was halted at 3,500 total passes, which is considered a sustainment level of traffic. At the conclusion of traffic, approximately 0.25 in. of permanent deformation was measured. 在总通行量达到 3500 次时停止通行,这被认为是维持通行的水平。交通结束时,测得约 0.25 英寸的永久变形。 Thus, a cement-stabilized repair technique could sustain P-8 traffic passes well beyond a contingency (500-pass) scenario. Posttraffic photographs of the cement-stabilized repair are shown in Figure 98. 因此,水泥稳定修复技术可维持 P-8 交通通行,远远超过应急(500 次通行)情况。图 98 显示了水泥稳定修复后的交通照片。
Figure 97. Permanent deformation of cement stabilized sand with FRP. 图 97.含玻璃钢的水泥稳定砂的永久变形。
Figure 98. Photographs of posttest cement stabilized backfill. 图 98.测试后水泥稳定回填土的照片。
(a) Overall view (a) 总览
(b) Close-up view (b) 近景
9.4 Repair 4: Compacted Debris with Stone and Grout 9.4 修复 4: 用石块和灌浆压实碎石
Repair 4 consisted of a stone and grout repair technique. Reclaimed PCC debris was used as the backfill material. Relatively large pieces of PCC debris were broken using a backhoe equipped with a breaker attachment. The targeted maximum size of the debris was approximately 9 in . 修复 4 包括石块和灌浆修复技术。回收的水泥混凝土碎块被用作回填材料。使用装有破碎机附件的反铲挖掘机破碎相对较大的混凝土碎块。碎石的目标最大尺寸约为 9 英寸。 After oversized material had been removed and/or further reduced in size, a skeleton bucket on a CTL was used to screen the debris. The openings between teeth on the skeleton bucket were approximately 2.5 in ., thus allowing material smaller than 2.5 in. 在清除过大的材料和/或进一步缩小尺寸后,使用 CTL 上的骨架铲斗筛分碎屑。骨架铲斗的齿间开口约为 2.5 英寸,因此可以将小于 2.5 英寸的材料筛分出来。 to fall through the bucket and be discarded. Therefore, final processed reclaimed debris had particle sizes ranging from 9 in. to 2.5 in. 因此,最终处理的再生碎屑颗粒大小在 9 英寸到 2.5 英寸之间。因此,最终处理的再生碎屑的颗粒大小从 9 英寸到 2.5 英寸不等。
A simulated crater was excavated to a depth of 16 in. , and the bottom of the excavation was leveled and recompacted. The processed PCC debris was placed in the excavation in one lift such that the debris was near the surface of the surrounding PCC slabs. 一个模拟陨石坑被挖掘至 16 英寸深。然后将挖掘底部整平并重新压实。将处理过的 PCC 碎料一次性放入挖掘坑中,使碎料接近周围 PCC 板的表面。 A metal straightedge was slowly moved across the surface of the PCC debris to inspect for unusually large voids and/or pieces of debris that extended above existing grade. 用金属直尺慢慢划过 PCC 瓦砾的表面,检查是否有异常大的空隙和/或超出现有地表的瓦砾碎片。 Large voids were filled by hand with additional small debris, and pieces extending above existing grade were either reoriented or removed and replaced. Small debris (i.e., particles ranging from 3//43 / 4 to 1//2in1 / 2 \mathrm{in}.) were placed in a 6 in . wide band around the perimeter of the crater. These materials allowed for proper grout penetration while reducing the potential for early joint spalling under traffic. 大的空隙由人工用更多的小碎石填补,超出现有地表的碎石要么被重新定位,要么被移除并替换。小碎石(即从 3//43 / 4 到 1//2in1 / 2 \mathrm{in} 的颗粒)被放置在火山口周边 6 英寸宽的区域内。这些材料既能使灌浆适当渗透,又能减少交通情况下早期接缝剥落的可能性。
A mortar mixer was moved adjacent to the simulated crater and filled with 32 gal . of water. A 6.5 lb container of calcium chloride accelerator was added to the mix water. 将一台灰泥搅拌机移到模拟火山口附近,并注入 32 加仑的水。在混合水中加入了一罐 6.5 磅的氯化钙促进剂。 Five 92.5 lb , Type I portland cement bags were added to the water/accelerator mixture, and the mixer was allowed to agitate for 30 sec . The grout mixture was then poured over the PCC 在水/促进剂混合物中加入五个 92.5 磅的 I 类波特兰水泥袋,并让搅拌器搅拌 30 秒。然后将灌浆混合物倒入 PCC
debris, and the mixing and placing process was repeated until sufficient batches of material had been placed to fill all voids and reach the surface of the crater. A magnesium screed was used to strike off excess grout. 然后重复搅拌和浇注过程,直到浇注的材料足够填满所有空隙并到达陨石坑表面。使用镁熨斗熨平多余的灌浆。 After initial set (approximately 30 min ) the repair was covered with plastic sheeting to prevent desiccation. 初凝后(约 30 分钟),用塑料布覆盖修复处,以防干燥。
Initial traffic was applied after approximately 20 hr of cure time and was continued up to 50 total passes. At this point, a hydraulic malfunction occurred on the HVS resulting in suspension of test traffic. 在大约 20 小时的固化时间后,开始进行最初的运输,总共运输了 50 次。此时,HVS 出现液压故障,导致测试暂停。 Traffic was restarted after diagnosing/repairing the HVS hydraulic malfunction. The total down time was approximately 33 days. 在诊断/修复 HVS 液压故障后,交通重新启动。总停机时间约为 33 天。 Thus, the cementitious repair materials had an unloaded cure time that was outside normal construction operations; this fact should be considered when interpreting the test results. 因此,水泥基修补材料的卸载固化时间超出了正常施工作业的范围;在解释测试结果时应考虑到这一事实。
Failure of the stone and grout repair technique was defined as one of more of the following: (1) high-severity shattered slab, (2) deflection in the interior of the repair greater than 1.5 in ., (3) presence of a severe tire hazard, or (4) a high-severity joint spall with a length of at least 2 ft , a width of at least 6 in ., and a depth of at least 2 in . 石材和灌浆修补技术的失败定义为以下情况之一:(1) 石板破碎严重,(2) 修复处内部变形超过 1.5 英寸,(3) 存在严重的轮胎危险,或 (4) 接缝剥落严重,长度至少 2 英尺,宽度至少 6 英寸,深度至少 2 英寸。 over at least 50%50 \% of the spall length as determined by visual inspection. 至少 50%50 \% 的剥落长度,由目测确定。
Results of the trafficking test indicated that the stone and grout repair technique reached the limiting spall criteria at 2,000 passes. No damage was observed at the 500 -pass inspection. Damage was first noted at the 1,000-1,000- pass inspection. While the spall met the limiting failure criteria at 2,000 passes, it did not present an operational concern for the HVS, and test traffic was continued until 3,500 passes. Photographs of spall progression are shown in Figure 99. 贩运测试结果表明,石材和灌浆修复技术在通过 2,000 次检查时达到了极限剥落标准。在 500 次检查中未发现损坏。 1,000-1,000- 次检查时首次发现损坏。虽然剥落在 2,000 次检测时达到了极限故障标准,但并没有对 HVS 的运行造成影响,因此测试继续进行,直到 3,500 次检测。图 99 显示了剥落过程的照片。
Pretraffic and posttraffic rod and level elevation measurements were made to assess deflection in the interior of the repair area. These measurements indicated that a global settlement on the order 0.30 in . occurred after the application of 3,500 P-8 passes. 对施工前和施工后的杆件和水平标高进行了测量,以评估维修区域内部的变形情况。这些测量结果表明,在使用 3,500 次 P-8 碾压后,出现了 0.30 英寸的整体沉降。 Simply, the repair tended to “punch” into the existing sublayers approximately 0.30 in . 简单地说,修补有 "打入 "现有底层约 0.30 英寸的趋势。
To characterize the strength change of the stone and grout repair technique, FWD tests were conducted after the initial cure and at the conclusion of traffic. 为确定石材和灌浆修复技术的强度变化,在初始固化后和交通结束时进行了 FWD 试验。 The FWD was positioned near the center of the repair, thus a portion of the deflection sensors were located on the in situ PCC pavement. Plate load and plate deflection were used for comparison purposes of pretraffic and posttraffic strength. FWD 位于修复中心附近,因此部分挠度传感器位于原位 PCC 路面上。平板载荷和平板挠度用于交通前和交通后强度的比较。 The initial ISM for the stone and grout repair technique 石材和灌浆修复技术的初始 ISM
was 2,385kips//in2,385 \mathrm{kips} / \mathrm{in}. The final ISM for the stone and grout repair technique was 335kips//in335 \mathrm{kips} / \mathrm{in}., representing a meaningful reduction in estimated load carrying capacity due to damage to the repair from traffic application. 为 2,385kips//in2,385 \mathrm{kips} / \mathrm{in} 。石材和灌浆修复技术的最终 ISM 为 335kips//in335 \mathrm{kips} / \mathrm{in} .
Figure 99. Spalling in stone and grout repair. 图 99:石材剥落和灌浆修复。
(a) Joint spalling at 1,000 passes (a) 1,000 次检测的接头剥落情况
(b) Joint spalling at 1,500 passes (b) 1 500 道次的接缝剥落
Repair 5 consisted of the placement of debris backfill that was surfaced with a calcium-sulfoaluminate (CSA) concrete cap. A simulated crater was excavated to a depth of 26 in . 修复 5 包括放置碎石回填土,表面覆盖硫铝酸钙 (CSA) 混凝土盖。模拟陨石坑被挖掘至 26 英寸深。 Oversized debris was broken using a breaking attachment on a backhoe to a maximum aggregate size of approximately 12 in . (Figure 100). The 12 in . size debris was placed in a single layer in the bottom of a simulated crater (Figure 101a). 使用反铲挖掘机上的破碎附件将过大的碎石破碎成最大约 12 英寸的骨料大小(图 100)。将 12 英寸大小的碎石单层放置在模拟陨石坑的底部(图 101a)。 A layer of sand was placed over the large-size debris and uniformly spread to fill in void space between the debris (Figure 101b). Thereafter, a layer of 9 in . 在大尺寸碎石上铺上一层沙子,并均匀铺开,以填补碎石之间的空隙(图 101b)。之后,再铺上一层 9 英寸厚的沙土(图 101b)。 size debris was placed in a single layer, and subsequently backfilled with sand to further fill remaining void space (Figure 101c and Figure 101d, respectively). The sand layer was placed in sufficient thickness such that the final CSA concrete capping layer would be 7 in . 大小的碎石被放置在单层中,随后用沙子回填,以进一步填满剩余的空隙(分别见图 101c 和图 101d)。砂层的厚度足以使最终的 CSA 混凝土封顶层达到 7 英寸。 thick. The sand layer was compacted with a pneumatic jumping jack; a total of two uniform coverages were applied. Finally, a plate compactor was used to complete final compaction and to provide a uniform final surface. 厚。砂层用气动千斤顶压实;总共进行了两次均匀的覆盖。最后,使用平板压实机完成最后的压实,以提供均匀的最终表面。 The depth was checked in multiple locations using a straightedge and folding carpenter’s ruler, and any areas not meeting the thickness requirements were adjusted. 使用直尺和折叠木工尺在多个位置检查深度,并对不符合厚度要求的区域进行调整。
The CSA concrete surfacing material consisted of a rapid-setting cementitious mixture composed of 3//4in3 / 4 \mathrm{in}. maximum size recycled concrete aggregate (RCA), concrete sand, CSA cement, Type I portland cement, set retarding admixture, and water. The 3//4in3 / 4 \mathrm{in}. maximum size aggregate was created by crushing PCC debris in a CTL crusher bucket attachment. CSA 混凝土面层材料是一种速凝水泥基混合物,由最大粒径的再生混凝土骨料 (RCA)、混凝土砂、CSA 水泥、I 类波特兰水泥、缓凝外加剂和水组成。 3//4in3 / 4 \mathrm{in} .最大粒径骨料是通过 CTL 破碎机铲斗附件破碎 PCC 碎石制成的。
(b) Placement of sand layer over 12 in. debris (b) 在 12 英寸碎石上铺设砂层
(d) Final sand layer prior to CSA placement (d) 铺设加固混凝土前的最终砂层
The CSA concrete surface material was prepared using a CTL mixing attachment. A second CTL with a split RCA/sand bucket was used to collect and transport component materials (Figure 102a). CSA 混凝土表面材料是用 CTL 搅拌附件制备的。第二台 CTL 带有分体式 RCA/砂斗,用于收集和运输成分材料(图 102a)。 The RCA/sand bucket was divided with a steel plate such that the proper amount of each material type could be loaded on each side. The process consisted of initially loading the mixer attachment with the RCA and then adding the concrete sand. 用钢板将 RCA/砂斗分开,以便在每一侧装入适量的每种材料。整个过程包括先将 RCA 装入搅拌机附件,然后再加入混凝土砂。 This aggregate combination was mixed for approximately 30 sec. Three 50 lb bags of CSA cement (Figure 102b) and one 47 lb bag of Type I portland cement were added to the mixture and dry mixed for approximately 30 sec (Figure 102 c102 c ). Thereafter, approximately 17 gal. of water and a setretarding admixture were added. The completed mixture was agitated for approximately 90 sec , and the completed mixture was discharged into the simulated crater (Figure 102d). 这种骨料组合混合了大约 30 秒。在混合物中加入三袋 50 磅的 CSA 水泥(图 102b)和一袋 47 磅的 I 型硅酸盐水泥,并干混约 30 秒(图 102 c102 c )。之后,加入约 17 加仑的水和一种缓凝外加剂。搅拌完成的混合物约 90 秒,然后将完成的混合物排入模拟火山口(图 102d)。 This process was repeated until sufficient material was produced to achieve the target finish elevation. 这个过程一直重复进行,直到生产出足够的材料来达到目标完成高度。
(d) Placement of CSA mixture into crater (d) 将 CSA 混合物放入火山口
Initial traffic (100 passes) was applied after approximately 6 hr of cure time. Rod and level elevation measurements and visual inspection were conducted at select traffic intervals. Elevation measurements indicated a global settlement on the order of 1.4 in. 大约 6 小时的固化时间后,开始施工(100 次)。在选定的交通时间间隔内,对杆件和水平标高进行了测量,并进行了目视检查。标高测量结果表明,整体沉降约为 1.4 英寸。 occurred by the completion of 3,500P-83,500 \mathrm{P}-8 passes (Figure 103). Most settlement (approximately 1.2 in.) occurred in the first 2,000 P-8 passes. 3,500P-83,500 \mathrm{P}-8 遍时出现(图 103)。大部分沉降(约 1.2 英寸)发生在最初的 2,000 个 P-8 道次中。
Joint spalling initiated at approximately 200 P-8 passes (Figure 104a). Although joint spalling increased with increased traffic passes (Figure 104), the spall did not progress to the point considered failure until 3,500 passes. 接头剥落始于大约 200 个 P-8 道次(图 104a)。虽然接头剥落随着通行次数的增加而加剧(图 104),但直到 3,500 次通行后,剥落才发展到被认为失效的程度。 Further, the spall did not present a meaningful tire hazard. 此外,这种剥落不会对轮胎造成严重危害。
Figure 104. Joint spalling of CSA repair. 图 104.CSA 修复的接缝剥落。
Strength change of the CSA repair technique was monitored using an FWD, and ISM values were determined at various traffic levels (Figure 105). The pretraffic ISM (after the 6 hr cure time) was approximately 1,150kips//in1,150 \mathrm{kips} / \mathrm{in}. A rapid decline in ISM was observed up to 500 passes (see Figure 105), and ISM values tended to stabilize thereafter. A slight upward trend was noted after 2,000 passes that may be attributed to densification and/or particle reorientation. 使用 FWD 监测了 CSA 修补技术的强度变化,并确定了不同交通水平下的 ISM 值(图 105)。通行前的 ISM 值(固化 6 小时后)约为 1,150kips//in1,150 \mathrm{kips} / \mathrm{in} 。在通过 500 次之前,ISM 值迅速下降(见图 105),之后 ISM 值趋于稳定。2,000 次后出现了轻微的上升趋势,这可能是由于致密化和/或颗粒重新定向造成的。 The final ISM at the conclusion of 3,500 passes was approximately 350kips//in350 \mathrm{kips} / \mathrm{in}., similar to the final ISM reported for the stone-and-grout repair. 在完成 3,500 道工序后,最终的 ISM 约为 350kips//in350 \mathrm{kips} / \mathrm{in} .,与报告的石块和灌浆修复的最终 ISM 相似。
Figure 105. ISM for CSA crater repair. 图 105.用于 CSA 凹坑修复的 ISM。
9.6 Repair 6: Rapid-Setting Flowable Fill Backfill with Rapid-Setting Concrete Mixture 9.6 修复 6:使用速凝混凝土混合物进行速凝可流动填料回填
Repair 6 consisted of a rapid-setting flowable fill backfill capped with a high-quality rapid-setting concrete. A simulated crater was excavated to a depth of 24 in ., and the bottom of the excavation was carefully leveled. 修补 6 包括用优质速凝混凝土覆盖的速凝流动填料回填。一个模拟弹坑被挖掘至 24 英寸深,挖掘底部被仔细整平。 Rapid-setting flowable fill was used to construct a 14 in. thick backfill layer. 快速凝固可流动填料用于建造 14 英寸厚的回填层。 An extendable boom forklift (Figure 106a) was used to position a super sack over the simulated crater, and the dry rapid-setting flowable fill blend was released into the crater and uniformly spread (Figure 106b) to achieve a 4 in . thick lift. Approximately 4 ogal . 使用可伸缩臂叉车(图 106a)将超级袋放置在模拟陨石坑上方,然后将干燥的速凝可流动混合填料释放到陨石坑中并均匀撒布(图 106b),以达到 4 英寸厚的提升效果。大约 4 千加仑。 of water was dispensed over the 的水喷洒在
surface of each lift via a 2 in . diam hose equipped with a shutoff nozzle and a flow meter (Figure 106c). Water was allowed to penetrate the dry-placed flowable fill for approximately 10 min , and the process was repeated until the target elevation was reached. 通过一根直径为 2 英寸的软管,在每个升降机的表面注入水,该软管配有一个关闭喷嘴和一个流量计(图 106c)。让水渗入干铺的可流动填料约 10 分钟,然后重复该过程,直到达到目标标高。 For the final lift, approximately 30 gal. of water was dispensed over the surface to reduce the amount of standing water on the surface of the flowable fill (Figure 106d). 最后一次提升时,在表面喷洒了约 30 加仑的水,以减少可流动填料表面的积水量(图 106d)。
A 10 in. thick rapid-setting concrete cap was placed over the rapid-setting flowable fill backfill layer using a simplified volumetric mixer (Figure 106e). The repair was allowed to cure for approximately 2 hr (Figure 106f), after which the HVS was positioned over the crater. 使用简易容积式搅拌机在速凝可流动填料回填层上浇筑 10 英寸厚的速凝混凝土盖(图 106e)。修补工作需要大约 2 小时的固化时间(图 106f),然后将 HVS 放置在凹坑上。 Test traffic was initiated after 2.75 hr from the time of rapid-setting cap placement. 测试交通从放置速凝盖起 2.75 小时后开始。
Rod and level measurements and visual inspections were conducted at select traffic intervals. Elevation measurements indicated global settlement of 0.12 in . occurred at the conclusion of 3,500P-83,500 \mathrm{P}-8 passes. 在选定的行车间隔时间进行了杆件和水平测量以及目视检查。标高测量结果表明,在 3,500P-83,500 \mathrm{P}-8 通行结束时,出现了 0.12 英寸的整体沉降。
Minor joint spalling (Figure 107) was observed in the rapid-setting concrete surface. The observed spalling did not meet the failure threshold, and there was minimal FOD development. 在速凝混凝土表面观察到轻微的接缝剥落(图 107)。所观察到的剥落未达到失效阈值,而且产生的 FOD 极少。
Stiffness changes in the rapid-setting repair were monitored using an FWD, and ISM values were determined at various traffic levels (Figure 108). The pretraffic ISM (after the 2.75 hr cure time) was approximately 2,960 kips/in. 使用 FWD 监测了速凝修补处的刚度变化,并确定了不同交通水平下的 ISM 值(图 108)。行车前的 ISM 值(固化 2.75 小时后)约为 2960 kips/in。 ISM values declined up to approximately 1,000 passes and generally stabilized thereafter. The final ISM at the conclusion of 3,500 passes was approximately 830kips//in830 \mathrm{kips} / \mathrm{in}. ISM 值下降到大约 1,000 次,之后总体趋于稳定。在完成 3 500 次检测后,最终的 ISM 值约为 830kips//in830 \mathrm{kips} / \mathrm{in} 。
Figure 106. Placement of rapid-setting flowable fill/concrete cap. 图 106.放置速凝可流动填料/混凝土盖。
(a) Positioning flowable fill over crater (a) 在火山口上放置可流动填料
(b) Spreading flowable fill to a uniform thickness (b) 将可流动填料摊铺成均匀厚度
(d) Completed flowable fill lift (d) 已完成的可流动填料提升
(f) Completed rapid set crater surface (f) 完成快速设置的陨石坑表面
Figure 107. Joint spalling at 3,500 passes on rapid-setting (RS) crater repair. 图 107.快速固化 (RS) 凹坑修补技术在 3,500 道工序上的接缝剥落。
Figure 108. ISM for rapid-setting concrete crater repair. 图 108.用于快速凝固混凝土凹坑修复的 ISM。
10 Forensic Investigation 10 法证调查
A forensic investigation was performed to measure posttraffic material properties and to study the flexible pavement mode of failure. Trenches approximately 5 ft wide were excavated near the center cross section of each flexible pavement test item. 为测量行车后的材料特性并研究柔性路面的失效模式,进行了法医调查。在每个柔性路面测试项目的中心横截面附近挖掘了约 5 英尺宽的沟槽。 Excavation began by saw-cutting the HMA surface and carefully removing it to minimize disturbance to the underlying base course. After forensic data were collected on the base layer, it was removed to expose the underlying subgrade layer. 挖掘工作从锯切 HMA 表层开始,小心翼翼地将其清除,以尽量减少对下层基层的干扰。在收集了基底层的取证数据后,将基底层移除,露出底层。 Layer deformation measurements, field CBR tests, nuclear density tests, and moisture content tests were made at each trench location. 在每个沟渠位置都进行了地层变形测量、实地 CBR 测试、核密度测试和含水量测试。
A robotic total station was used to determine permanent layer deformation at 6 in. intervals on the surface of each excavated pavement layer. These results are shown in Figures 109 to 114. Photographs of the excavated cross sections are shown in Figure 115. 使用机器人全站仪以 6 英寸的间隔测定每个挖掘路面层表面的永久变形。这些结果如图 109 至图 114 所示。挖掘横截面照片见图 115。 Layer interfaces are highlighted by a red dashed line. Rutting in each layer was calculated by averaging the maximum elevation (upheaval) on each side of the wheel path and subtracting the minimum elevation (bottom of rut) within the wheel path. 层界面用红色虚线标出。各层车辙的计算方法是:车轮轨迹两侧的最大高程(上浮)的平均值减去车轮轨迹内的最小高程(车辙底部)。 Additionally, a similar analysis technique was made on construction crosssection elevation measurements to remove any abnormalities during construction. This approach “zeroed” the data and allowed for capturing only deformation that could be attributed to traffic application. 此外,对施工断面高程测量也采用了类似的分析技术,以消除施工期间的任何异常情况。这种方法将数据 "归零",只捕捉可归因于交通应用的变形。 Thus, calculated rut-depth values via total station measurement techniques (Table 20) may be different from those measured with a straightedge. 因此,通过全站仪测量技术计算出的车辙深度值(表 20)可能与用直尺测量出的值不同。 However, the measurements are useful in examining the magnitude of rutting in each layer relative to each other and understanding how each layer contributed to overall observed failure. 不过,这些测量结果对于检查各层车辙的相对严重程度以及了解各层对所观察到的总体破坏的影响非常有用。
For the weak gravel base test items, surface deformation measurements indicated that the greatest deformation was generally measured in the base layer. This observation was expected, because the strength (CBR) of the gravel layer was well below current minimum specifications. 对于软弱砾石基层测试项目,表面变形测量结果表明,最大的变形一般是在基层测量到的。这一结果在意料之中,因为砾石层的强度(CBR)远低于当前的最低规格。 The thickness of the relatively thin asphalt layers was inadequate to distribute the applied loads to the relatively weak base. 相对较薄的沥青层厚度不足以将外加荷载分散到相对薄弱的基础上。 Additionally, the deformation measurements reinforced the need for a competent aggregate layer to sustain the heavy wheel loads and high tire pressures from the P-8 test gear. 此外,变形测量结果表明,P-8 试验装置需要一个合格的骨料层来承受重车轮载荷和高轮胎压力。
For test items containing a high-quality limestone base, general observations were that the greatest measured deformation occurred in the subgrade except for the 2 in. thick HMA on the 6 CBR subgrade. These data suggest that on the weaker subgrade, a 2 in. 对于含有优质石灰岩基层的测试项目,一般观察结果表明,除了在 CBR 值为 6 的基层上铺设 2 英寸厚的 HMA 外,测量到的最大变形发生在基层上。这些数据表明,在较弱的基层上,2 英寸厚的 HMA 会产生较大的变形。 thick HMA layer was insufficient to adequately protect the aggregate base course. This observation reinforces the recommendation for a minimum 4 in. thick HMA layer. 厚的 HMA 层不足以充分保护骨料基层。这一观察结果加强了至少使用 4 英寸厚 HMA 层的建议。
10.2 Posttraffic Material Properties 10.2 施工后的材料特性
Measured posttraffic material properties are shown in Table 21. Changes in material properties (posttraffic minus as-built properties are summarized in Table 22. 测量的交通后材料特性见表 21。表 22 汇总了材料属性的变化(交通后属性减去竣工属性)。 Measured properties represent measurements made in the traffic wheel-path, thus highlight the changes that could be attributed to traffic application. 测量到的属性代表了在交通轮迹中进行的测量,从而突出了可归因于交通应用的变化。
In the aggregate base layer, an increase in measured compaction was generally observed that could be attributed to aggregate densification under traffic loading and slight reductions in measured moisture content. 在骨料基层中,一般都能观察到测量压实度的增加,这可能是由于骨料在交通荷载作用下发生了致密化,以及测量含水量略有降低。 Increases in CBR in the limestone base layer were measured; however, in the case of the gravel base layer, reductions in CBR were measured. These data tend to 测得石灰岩基层的 CBR 有所增加;但测得砾石基层的 CBR 有所减少。这些数据倾向于
indicate that stress-hardening occurred in the semi-cohesive limestone layer (i.e., measured strength tended to improve with the application of load.) Reductions in CBR in the gravel base layer corroborate forensic elevation measurements in which the greatest deformation was observed in the gravel layer. 砾石基层 CBR 的降低证实了法医标高测量的结果,即砾石层的变形最大。 This suggests that the initially weak gravel layer was a meaningful contributor to pavement failure. 这表明,最初薄弱的砾石层是导致路面破坏的重要因素。
Minor changes were observed in the CH subgrade layer in most cases. 在大多数情况下,CH 基层发生了轻微变化。 Compaction measurements generally indicated a decrease in compaction was observed in some items (4HMA over GR over 10 CBR and 4HMA over LS over 10 CBR), while a slight increase was observed in the other test items. No clear trend could be identified; however, the largest increase was observed in the 2HMA over LS over 6 CBR test item. 压实度测量结果普遍表明,某些测试项目的压实度有所下降(超过 10 CBR 的 4HMA 压实 GR 和超过 10 CBR 的 4HMA 压实 LS),而其他测试项目的压实度略有上升。没有发现明显的趋势;不过,在 2HMA over LS over 6 CBR 测试项目中观察到的增幅最大。 Similar observations were made regarding measured subgrade CBR. These data suggest that a meaningful amount of densification occurred near the surface of the weaker 6 CBR subgrade layer under P-8 traffic. 在测量的路基 CBR 方面也发现了类似的情况。这些数据表明,在 P-8 交通量下,CBR 值为 6 的较弱路基层表面附近发生了一定程度的致密化。 The instrumentation response data (SDD data in particular) tend to confirm these observations: the 2HMA over LS over 6 CBR test item displayed the highest dynamic and permanent subgrade deflection early in traffic application. 仪器响应数据(特别是 SDD 数据)倾向于证实这些观察结果:2HMA over LS over 6 CBR 测试项目在交通应用早期显示出最高的动态和永久性路基挠度。
Table 21. Posttraffic material properties. 表 21.交通后材料特性。
11 Implications for Flexible Pavement Design 11 对柔性路面设计的影响
An analysis was performed to investigate how the results of the flexible pavement traffic tests agreed with existing performance criteria and to develop improved performance predictions. The analyses are described in this chapter. 我们进行了一项分析,以研究柔性路面交通测试结果与现有性能标准的一致性,并对性能预测进行改进。本章将介绍分析结果。
11.1 Comparison to Existing Design Methodology 11.1 与现有设计方法的比较
Team members compared the passes to failure from the full-scale trafficking tests with performance predictions made using current DoD models and criteria. 团队成员将全尺寸贩运试验的通过率与使用当前国防部模型和标准进行的性能预测进行了比较。 The recently released Pavement-Transportation Computer Assisted Structural Engineering (PCASE) Version 7.0 was used to determine predicted passes to failure based on as-constructed pavement layer thicknesses and material properties. 最近发布的路面-交通计算机辅助结构工程(PCASE)7.0 版用于根据施工路面层厚度和材料特性确定预测的故障通过率。 Specifically, the Airfield Pavement Evaluation (APE) module was used to predict allowable passes to failure. The APE module provides the user with a means to select general layer types, select material types, input material thicknesses, and input layer CBR properties. 具体而言,机场路面评估 (APE) 模块用于预测允许通过的故障点。APE 模块为用户提供了选择一般层类型、选择材料类型、输入材料厚度和输入层 CBR 属性的方法。 These capabilities are appropriate for the construction data contained in this report and are appropriate for the types of field data available in an expeditionary environment. 这些功能适用于本报告中的施工数据,也适用于远征环境中的实地数据类型。 The module uses a multi-step process where the passes to failure are computed for each material layer, and the minimum passes to failure represent overall passes to failure for the pavement section. 该模块采用多步骤流程,计算每个材料层的失效通过率,最小失效通过率代表路面断面的总体失效通过率。 Calculated passes to failure are based on traditional long-term design failure criteria for flexible pavements ( 1 in . rut depth). 计算的故障通过量基于传统的柔性路面长期设计故障标准(1 英寸车辙深度)。
A comparison of actual and predicted passes to failure utilizing the BetaAlpha hybrid criteria is shown in Table 23. In most cases for 1 in. 表 23 显示了使用 BetaAlpha 混合标准的实际和预测故障通过率的比较。在大多数情况下,对于 1 in. of rutting, researchers observed that actual passes to failure were greater than predicted passes to failure suggesting there is a level of conservatism in the existing performance criteria. Notably, APE overpredicted passes to failure for the 4 in . 研究人员观察到,实际塌方通过率大于预测塌方通过率,这表明现有性能标准存在一定程度的保守性。值得注意的是,APE 对 4 in . HMA over LS over 6 CBR test item. 在 6 个 CBR 测试项目中,HMA 碾压 LS。
Similarly, a comparison of actual and predicted passes to failure utilizing the Alpha criteria is shown in Table 24. 同样,表 24 显示了采用 Alpha 标准的实际和预测故障通过率的比较。 In both cases we found that the current performance criteria did not provide an adequate prediction of passes to failure for these relatively weak airfield pavement structures. Further, existing performance criteria are generally based on the results of 在这两种情况下,我们发现目前的性能标准并不能充分预测这些相对较弱的机场路面结构的失效通过率。此外,现有的性能标准通常基于
historical test data where failure was considered 1 in . of rutting; thus, they are not explicitly applicable to contingency operations where an accurate prediction of relatively low passes may be expected, and much greater allowable rut depths on the order of 2 in . 根据历史测试数据,车辙深度为 1 英寸就会出现故障;因此,这些数据并不明确适用于应急作业,因为在应急作业中,可能会对相对较低的通过量进行准确预测,而允许的车辙深度要大得多,约为 2 英寸。 are allowed. 是允许的。
Table 23. Comparison of PCASE7 (Beta-Alpha hybrid) predicted passes to failure and actual passes to failure. 表 23.PCASE7 (β-阿尔法混合型)预测故障通过率与实际故障通过率的比较。
11.2 Permanent Deformation Modeling for Contingency Criteria 11.2 为应急标准建立永久变形模型
To address the inadequacy of the existing design methodologies, a modeling effort was initiated. 为了解决现有设计方法的不足,我们启动了建模工作。 In a classical mechanistic-empirical (cME) method, such as that currently used in PCASE, pavement response is calculated using the initial structural condition of the pavement, and an empirical transfer function is used to predict the number of load repetitions to failure. 在经典的机械-经验(cME)方法中,如 PCASE 目前使用的方法,路面响应是通过路面的初始结构条件来计算的,并使用经验传递函数来预测至破坏的荷载重复次数。 The load repetitions to failure are constrained by data gathered during accelerated pavement testing, which has traditionally been based on approximately 1.0 in. of rutting. Furthermore, this procedure is best suited for the performance of permanent airfields. 加速路面测试过程中收集的数据限制了破坏荷载的重复次数,传统的路面测试以大约 1.0 英寸的车辙为基础。此外,该程序最适合永久性机场的性能。
However, the nature and urgency of contingency operations allow for less stringent rutting criteria ( 2.0 in. rutting for the P-8\mathrm{P}-8 ), thus making direct application of the cME method more difficult. Therefore, a new performance prediction method was developed based on the permanent deformation (PD) models used in the AASHTO Mechanistic-Empirical Pavement Design Guide (MEPDG [Witczak and El-Basyouny 2004]). 然而,由于应急行动的性质和紧迫性,车辙标准并不严格( P-8\mathrm{P}-8 的车辙为 2.0 英寸),因此更难直接应用 cME 方法。因此,根据《美国公路学会机械-经验路面设计指南》(MEPDG [Witczak 和 El-Basyouny 2004])中使用的永久变形 (PD) 模型,开发了一种新的性能预测方法。
11.2.1 Fundamental Equations of the Permanent Deformation Model 11.2.1 永久变形模型的基本方程
The PD model is fundamentally a mechanistic-empirical method, as it first computes a mechanistic response at predefined points within a theoretical layered elastic structure due to an aircraft load. PD 模型从根本上说是一种力学-经验方法,因为它首先计算的是飞机载荷在理论分层弹性结构中预定点的力学响应。 It then relates these responses to progressive rutting performance through empirical relationships. The PD model uses layered elastic (LE) theory to compute this mechanistic response. 然后通过经验关系将这些响应与渐进车辙性能联系起来。PD 模型使用分层弹性(LE)理论来计算这种机理响应。 Whereas traditionally the cME method computes the vertical strain (or stress) at the top of the subgrade only to relate to subgrade rutting performance, the PD model accumulates permanent strains from deep within the subgrade up through the structure to the surface. 传统的 cME 方法只计算路基顶部的垂直应变(或应力),以便与路基车辙性能相关联,而 PD 模型则从路基深处通过结构向地表累积永久应变。 This is accomplished through a sublayering approach, as shown in Figure 116. 如图 116 所示,这是通过分层方法实现的。
Figure 116. Sublayering approach for decomposing the pavement structure with predefined analysis depths. 图 116.采用分层方法分解具有预定分析深度的路面结构。
The total accumulated permanent deformation is computed by summing the plastic strains from each sublayer within their respective thicknesses, as shown in Equation 1. 如公式 1 所示,累计永久变形总量的计算方法是将每个子层在各自厚度范围内的塑性应变相加。
delta_(a)(N)=sum_(i=1)^(NL)sum_(j=1)^(NSL)epsi_(ij)^(p)(N)Deltaz_(ij)\delta_{a}(N)=\sum_{i=1}^{N L} \sum_{j=1}^{N S L} \varepsilon_{i j}^{p}(N) \Delta z_{i j}
where 其中 delta_(a)=\delta_{a}= permanent deformation of pavement (inches), delta_(a)=\delta_{a}= 路面永久变形(英寸)、 epsi_(ij)^(p)=\varepsilon_{i j}^{p}= plastic strain of sublayer jj in layer ii, epsi_(ij)^(p)=\varepsilon_{i j}^{p}= 层 ii 中 jj 子层的塑性应变、 Deltaz_(ij)=\Delta z_{i j}= thickness of sublayer jj in layer ii, Deltaz_(ij)=\Delta z_{i j}= 层 ii 中 jj 子层的厚度、 N=N= number of passes of aircraft (or heavy vehicle simulator), N=N= 飞机(或重型车辆模拟器)的通过次数、 NL=N L= number of pavement layers, and NL=N L= 路面层数,以及 NSL=N S L= number of sublayers in a particular pavement layer. NSL=N S L= 特定路面层的子层数。
There are three different material models used to compute the plastic strain used in Equation 1-an HMA material model, an unbound aggregate material model, and a subgrade material model. 有三种不同的材料模型可用于计算等式 1 中使用的塑性应变--HMA 材料模型、无粘结骨料材料模型和路基材料模型。 The HMA material model (Equation 2) is given in terms of HMA temperature, pass level, and resilient vertical strain. HMA 材料模型(公式 2)是根据 HMA 温度、通过水平和弹性垂直应变给出的。
epsi_(1j)^(p)(N)=epsi_(v)(beta_(1)aT^(beta_(2)b)N^(beta_(3)c)),\varepsilon_{1 j}^{p}(N)=\varepsilon_{v}\left(\beta_{1} a T^{\beta_{2} b} N^{\beta_{3} c}\right),
where 其中 epsi_(1j)^(p)=\varepsilon_{1 j}^{p}= accumulated plastic strain in sublayer jj of HMA layer after NN load repetitions, epsi_(1j)^(p)=\varepsilon_{1 j}^{p}= 在 NN 重复加载后,HMA 层 jj 子层的累积塑性应变、 beta_(1),beta_(2),beta_(3)=\beta_{1}, \beta_{2}, \beta_{3}= locally calibrated material constants, a,b,c=a, b, c= globally calibrated regression constants, and epsi_(v)=\varepsilon_{v}= resilient vertical strain computed in sublayer using LE theory. beta_(1),beta_(2),beta_(3)=\beta_{1}, \beta_{2}, \beta_{3}= 局部校准的材料常数, a,b,c=a, b, c= 全局校准的回归常数,以及 epsi_(v)=\varepsilon_{v}= 利用 LE 理论计算的子层弹性垂直应变。
The unbound aggregate material and subgrade material models are of the same form, Equation 3: 无粘结骨料和基层材料模型的形式相同,即公式 3:
where 其中 epsi_(ij)^(p)=accumulated\varepsilon_{i j}^{p}=\operatorname{accumulated} plastic strain in sublayer jj of layer ii after NN load repetitions, NN 重复加载后, ii 层 jj 子层的 epsi_(ij)^(p)=accumulated\varepsilon_{i j}^{p}=\operatorname{accumulated} 塑性应变、 beta_(1)=\beta_{1}= calibration parameter for unbound and subgrade materials, (epsi_(0))/(epsi_(r)),beta,rho=\frac{\varepsilon_{0}}{\varepsilon_{r}}, \beta, \rho= material properties obtained through transfer functions, and epsi_(v)=\varepsilon_{v}= resilient vertical strain computed in sublayer using LE theory. beta_(1)=\beta_{1}= 无粘结材料和基层材料的校准参数, (epsi_(0))/(epsi_(r)),beta,rho=\frac{\varepsilon_{0}}{\varepsilon_{r}}, \beta, \rho= 通过传递函数获得的材料特性,以及 epsi_(v)=\varepsilon_{v}= 使用 LE 理论计算的基层弹性垂直应变。
The parameters (epsi_(0))/(epsi_(r)),beta\frac{\varepsilon_{0}}{\varepsilon_{r}}, \beta, and rho\rho are determined through empirical transfer functions or constants, based on whether the materials are characterized as an unbound granular material (Equation 4a4 a to 4c4 c ) or a subgrade material (Equation 5a5 a to 5c5 c ). 参数 (epsi_(0))/(epsi_(r)),beta\frac{\varepsilon_{0}}{\varepsilon_{r}}, \beta 和 rho\rho 是通过经验传递函数或常数确定的,取决于材料的特征是非结合粒状材料(公式 4a4 a 至 4c4 c )还是基层材料(公式 5a5 a 至 5c5 c )。
where 其中 omega_(c)=\omega_{c}= water content as a function of CBR (%), theta=\theta= bulk stress (psi), and omega_(c)=\omega_{c}= 含水量与 CBR 的函数关系(%)、 theta=\theta= 体积应力(psi)和 E(t)=E(t)= modulus as a function of time (load repetitions). E(t)=E(t)= 模量与时间(负载重复次数)的函数关系。
11.2.2 Aircraft Wander 11.2.2 飞机漫游
An important feature of the PD model is its discrete approach to modeling vehicle wander. PD 模型的一个重要特点是采用离散方法来模拟车辆漂移。 In addition to the predefined analysis depths using the sublayer approach described in Figure 116, a series of analysis points aligned in the transverse direction extending across the entire width of the test section are used to account for the accumulated permanent deformation due to different lateral offsets of the dual P-8 tires. 除了使用图 116 所述的子层方法预定义分析深度外,还使用了一系列横向排列的分析点,这些分析点横跨整个试验段宽度,用于计算双 P-8 轮胎不同横向偏移造成的累积永久变形。 Stated differently, pavement damage (permanent deformation) is accumulated at each transverse analysis point every single pass of the HVS. 换句话说,路面损坏(永久变形)会在 HVS 的每个横向分析点累积。 The significance of this approach cannot be overstated-rather than computing damage within the footprint of the landing gear, the PD model accumulates damage across the entire width of the test section each HVS pass, regardless of the lateral offset location of the HVS. 这种方法的重要性无论如何强调都不过分--PD 模型不是计算起落架足迹范围内的损坏,而是累积每次通过 HVS 时测试区段整个宽度上的损坏,无论 HVS 的横向偏移位置如何。 Damage then is a function of the degree of stress experienced each pass rather than tire location. 因此,损坏是每次通过时所受应力程度的函数,而不是轮胎位置的函数。
Reviewing Figure 117, one can see the dual P-8 gear moving laterally each pass as the HVS shifts position. The permanent deformation due to the moving gear load is computed at each analysis point (red dots) along the entire width of the test section each pass. 查看图 117,可以看到双 P-8 齿轮在 HVS 移动位置时每次都会横向移动。移动齿轮载荷导致的永久变形是沿着测试部分的整个宽度在每个分析点(红点)计算出来的。 The fundamental principle of the PD model used in this study is that stress is experienced in some degree at every analysis point each pass regardless of whether the tires from the HVS are directly over those points. 本研究中使用的 PD 模型的基本原理是,无论 HVS 的轮胎是否直接经过每个分析点,这些点都会在一定程度上受到应力。
Figure 117. Use of transverse analysis points across width of test section to accumulate permanent deformation during each vehicle pass with wander. 图 117.使用横向分析点横跨试验段宽度,累计车辆每次通过时的永久变形。
11.2.3 Incremental Damage 11.2.3 递增损伤
One characteristic difference between the cME method and the proposed PD model is that the cME method provides only the projected number of load repetitions to a predefined failure level (e.g., 1.0 in . cME 方法与拟议的 PD 模型之间的一个显著区别是,cME 方法只提供到预定失效水平(如 1.0 in . of rutting), while the PD model provides a history of accumulated permanent deformation for increased levels of load applications based on an incremental damage approach. 而永久变形模型则根据增量破坏方法,提供了载荷增加时永久变形的累积历史。 Not only is damage accumulated across the entire transverse width of the test section each HVS pass, but damage is also accumulated over time. This provides a history of the development of permanent deformation with increasing load applications. 在每次通过 HVS 时,不仅试验截面的整个横向宽度上会累积损伤,而且损伤也会随着时间的推移而累积。这提供了永久变形随着载荷增加而发展的历史。 For example, while a rutdepth criterion of 2.0 in . 例如,虽然车辙深度标准为 2.0 英寸 . was used in this study for the design of contingency flexible pavement structures under a P-8 loading, the proposed PD model easily accommodates the computation of the passes to failure for a particular pavement structure for a modified 2.25 in . 在本研究中,PD 模型被用于设计 P-8 荷载下的应急柔性路面结构。 rutdepth criteria as shown in Figure 118. In this manner the PD model makes better use of the incremental data collected during full-scale testing and provides a more comprehensive pavement damage approach. 车辙深度标准,如图 118 所示。通过这种方式,PD 模型可以更好地利用全尺寸测试期间收集的增量数据,并提供一种更全面的路面损坏方法。
Figure 118. Screenshot of PD model user interface, with plotted rut-depth history and computed pass level for a modified 2.25 in. rut-depth criteria. 图 118.PD 模型用户界面截图,图中绘制了车辙深度历史记录,并计算了修改后的 2.25 英寸车辙深度标准的通过水平。
11.2.4 Modulus Deterioration 11.2.4 模量劣化
Another salient feature of the PD model is the methodology to account for modulus deterioration. PD 模型的另一个突出特点是采用了模量劣化计算方法。 One can observe in the ISM plots in Figure 59 that there was a noticeable deterioration of each pavement structure’s ability to resist deformation under the FWD loading with increased levels of traffic. 从图 59 中的 ISM 图中可以看出,随着交通量的增加,每种路面结构在全轮驱动荷载下抵抗变形的能力都明显下降。 This is indicative of a change in the pavement structure’s stiffness/strength. This could be due to elastic shakedown of the structure under initial loading or possibly due to contributions from plastic deformation. Werkmeister et al. 这表明路面结构的刚度/强度发生了变化。这可能是由于结构在初始荷载下的弹性震荡,也可能是由于塑性变形造成的。Werkmeister 等人 (2001) provide an overview of shakedown theory. (2001) 概述了 "抖动 "理论。 This includes an initial elastic response followed by an elastic shakedown phase consisting of elastic settlement of the granular layers, which is proceeded by a plastic shakedown phase where the structure displays a steady-state, purely elastic, resilient response and concludes with an incremental collapse and ratcheting phase where plastic strains accumulate rapidly due to the mobilization of shear planes. 这包括最初的弹性响应,然后是由颗粒层弹性沉降组成的弹性摇晃阶段,接着是结构显示稳态、纯弹性、弹性响应的塑性摇晃阶段,最后是由于剪切面的移动而导致塑性应变快速累积的增量坍塌和棘轮阶段。 Based on the rutting and ISM histories from this study, it seems that there was a rapid transition from the elastic phase to the incremental collapse phase at very low pass levels. 根据这项研究中的车辙和 ISM 历史记录,似乎在非常低的通量下,弹性阶段就会迅速过渡到增量塌陷阶段。
Furthermore, at a certain point in almost all the test items, there seems to be a hardening that occurs where the ISM levels off to a steady state value. 此外,在几乎所有测试项目的某一点上,似乎都会出现一种硬化现象,即 ISM 达到一个稳定状态值。 While at first glance, it may appear that this could correspond to the plastic shakedown phase described above, it must be distinguished from this due to the high level of accumulated rutting occurring in the structure. To clarify, 乍一看,这可能与上文所述的塑性晃动阶段相对应,但由于结构中出现了大量累积车辙,因此必须将其与塑性晃动阶段区分开来。说明一下、
“hardening” in this sense is referring to the strain hardening that occurs in the plastic regime during the incremental collapse and ratcheting phase in shakedown theory. 这里的 "硬化 "指的是在振动理论中的增量塌陷和棘轮阶段的塑性机制中发生的应变硬化。 Beyond this point, geo-materials reach another kind of steady state condition where there is continuous accumulation of plastic strains with little change in the material modulus (i.e., the ratio of the stress and strain). 超过这一点,土工材料就会达到另一种稳定状态,即塑性应变不断累积,而材料模量(即应力和应变的比率)几乎没有变化。 At this point, the ratcheting behavior from shakedown theory might be described as the “kinematic hardening” of the geo-material under repeated loading. These complex phenomena are typically discarded in conventional pavement performance methodologies. 此时,晃动理论中的棘轮行为可被描述为土工材料在重复加载下的 "运动硬化"。这些复杂的现象通常在传统的路面性能方法中被忽略。 However, it is clear from other data collected (e.g., EPC measurements) that this variation over time must be accounted for in overloaded contingency flexible pavement structures. 不过,从收集到的其他数据(如 EPC 测量)可以清楚地看出,超载应急柔性路面结构必须考虑这种随时间的变化。 Consequently, a simple modulus deterioration model (Equation 6) was developed that causes an initial decrease in the upper two layers of the pavement structure followed by a linear hardening of the layer moduli. 因此,我们开发了一个简单的模量劣化模型(公式 6),该模型可使路面结构的上两层模量最初下降,随后各层模量呈线性硬化。 The current version of this model is a function of the permanent deformation history in the structure where deterioration transitions to hardening upon accumulating a certain level of rutting. This model was calibrated based on the rut-depth history and ISM history plots. 该模型的当前版本是结构中永久变形历史的函数,当车辙累积到一定程度时,劣化就会过渡到硬化。该模型根据车辙深度历史记录和 ISM 历史记录图进行校准。
E(t)={[E_(0)[1-gamma log(N)]," when "delta_(a) < delta_("limit ")","],[E_("steady ")," when "delta_(a) >= delta_("limit ")]:}E(t)= \begin{cases}E_{0}[1-\gamma \log (N)] & \text { when } \delta_{a}<\delta_{\text {limit }}, \\ E_{\text {steady }} & \text { when } \delta_{a} \geq \delta_{\text {limit }}\end{cases}
where 其中 E(t)=E(t)= layer modulus as a function of time ( NN load repetitions) (psi), E_(0)=E_{0}= initial design layer modulus before traffic (psi), gamma=\gamma= layer modulus decay parameter, E_("Steady ")=E_{\text {Steady }}= steady state layer modulus (psi), delta_(a)=\delta_{a}= current accumulated permanent deformation (in.), and delta_("limit ")=\delta_{\text {limit }}= permanent deformation marking transition from deterioration to hardening (in.). E(t)=E(t)= 层模量与时间的函数关系( NN 载荷重复次数)(psi)、 E_(0)=E_{0}= 交通前的初始设计层模量(psi)、 gamma=\gamma= 层模量衰减参数、 E_("Steady ")=E_{\text {Steady }}= 稳定状态层模量(psi)、 delta_(a)=\delta_{a}= 当前累积永久变形(英寸)和 delta_("limit ")=\delta_{\text {limit }}= 标志着从劣化到硬化过渡的永久变形(英寸)。
The steady state modulus E_("Steady ")E_{\text {Steady }} is not predefined but is a function of the accumulated permanent deformation delta_("limit ")\delta_{\text {limit }} that marks the transition from deterioration to hardening. This transition in permanent deformation must be representative of the behavior observed in the ISM plots and the response measurements in the EPC and rut-depth data. 稳态模量 E_("Steady ")E_{\text {Steady }} 不是预先确定的,而是累积永久变形 delta_("limit ")\delta_{\text {limit }} 的函数,它标志着从劣化到硬化的过渡。永久变形的这种转变必须能够代表在 ISM 图中观察到的行为以及在 EPC 和 rut-depth 数据中的响应测量结果。 Careful study of all the test item rut-depth histories and ISM plots showed that the limiting permanent deformation for the flexible pavement was approximately 0.6 in. Typically, a sharp bend was observed in both the ISM plots and the 对所有测试项目的车辙深度历史和 ISM 图的仔细研究表明,柔性路面的极限永久变形约为 0.6 英寸。通常情况下,在 ISM 图中都会观察到急剧弯曲。
rut-depth histories at this point. The rate of decay characterized by the layer modulus decay parameter gamma\gamma was calibrated by a sensitivity analysis. Multiple calls were made to the LE response model using a trial section under the FWD load to obtain a feasible relationship between variation of the layer moduli and corresponding ISM. 此时的层深度历史。层模量衰减参数 gamma\gamma 所表征的衰减速率是通过敏感性分析校准的。在全轮驱动荷载作用下,使用试验段对 LE 响应模型进行了多次调用,以获得层模量变化与相应的 ISM 之间的可行关系。
Traditional cME methods often assume there is a simplified relationship between the tire load, tire contact pressure, and tire contact area. Of these three tire parameters, the tire load is typically known while the other two require assumptions. 传统的 cME 方法通常假设轮胎负荷、轮胎接触压力和轮胎接触面积之间存在简化关系。在这三个轮胎参数中,轮胎负荷通常是已知的,而其他两个则需要假设。 First, the contact pressure at the tire-pavement interface is assumed to be equivalent to the inflation pressure inside the tire. 首先,假定轮胎与路面界面的接触压力等同于轮胎内部的充气压力。 Having made this first assumption, a second assumption is then made concerning the estimation of the contact area (namely, that the contact area equals the tire load divided by the inflation pressure). 在做出第一个假设后,第二个假设涉及接触面积的估算(即接触面积等于轮胎负荷除以充气压力)。 This is a reasonable assumption for conventional pavement design for sustainment and permanent airfields where rutting occurs in the subgrade far from the load. 这是为维持机场和永久机场进行常规路面设计时的合理假设,因为车辙发生在远离荷载的路基上。 In contingency operations where exceptionally thin pavement structures are encountered, however, there is an increased risk for base failures. Therefore, particular attention must be made to the nonuniform shape of the tire contact pressures. 然而,在遇到路面结构特别薄的应急行动中,路基失效的风险会增加。因此,必须特别注意轮胎接触压力的不均匀形状。 While the inflation pressure is uniform across the entire inside wall of the tire, the contact pressure at the tire-pavement interface is nonuniform in nature. 虽然整个轮胎内壁的充气压力是均匀的,但轮胎与路面界面的接触压力却是不均匀的。 The true shape of the contact pressure distribution is a function of the tire load, inflation pressure, age of the tire, and pavement surface type (among other variables). 接触压力分布的真实形状是轮胎负荷、充气压力、轮胎使用年限和路面类型(以及其他变量)的函数。
A simple method is implemented into the LE response model within the proposed PD model that estimates the P-8 nonuniform contact pressure by assuming the tire interacts with the pavement surface like a rigid circular foundation (Stache and Robinson 2022). 在拟议的 PD 模型中,LE 响应模型采用了一种简单的方法,通过假设轮胎与路面表面的相互作用就像刚性圆形地基一样,来估算 P-8 非均匀接触压力(Stache 和 Robinson,2022 年)。 This approach assumes that the contact pressure distribution corresponds to high sidewall pressures, characteristic of both aircraft tires and rigid circular foundations (Tielking 1989; Davis and Selvadurai 1996). 这种方法假设接触压力分布与飞机轮胎和刚性圆形地基所特有的高侧壁压力相对应(Tielking,1989 年;Davis 和 Selvadurai,1996 年)。
While initially this contact pressure distribution is not known, it can be ascertained through inverse analysis such that the contact pressure over the given contact area measured in Figure 24 is statically equivalent to the HVS P-8 tire load (approximately 44,500 lbf). 虽然最初不知道这种接触压力分布,但可以通过逆向分析来确定,这样在图 24 中测量到的给定接触面积上的接触压力就相当于 HVS P-8 轮胎的静态载荷(约 44,500 磅)。 Using this approach, an approximate contact pressure distribution was obtained as shown in Figure 119. It is important to reiterate that the computed contact pressure 使用这种方法,可以得到近似的接触压力分布,如图 119 所示。需要重申的是,计算出的接触压力
distribution shown in Figure 119 is statically equivalent to the load applied to each tire by the HVS. This can be easily confirmed by integrating the contact pressure distribution over the domain of the contact area. 图 119 所示的压力分布在静态上等同于 HVS 施加在每个轮胎上的载荷。通过对接触区域内的接触压力分布进行积分,可以很容易地确认这一点。
Figure 119. Approximation of nonuniform contact pressure of P-8 tire using the proposed method based on inverse analysis. 图 119.使用基于反分析的拟议方法对 P-8 轮胎的非均匀接触压力进行近似计算。
The importance of accurately modeling the contact pressure, particularly for thin flexible pavement structures, is tied to the PD model’s mechanisticempirical process. 对接触压力进行精确建模的重要性,尤其是对薄的柔性路面结构而言,与 PD 模型的力学-经验过程息息相关。 The formulations described in Equations (1) through (5) above are based on an accurate calculation of the stress state at various points in the pavement structure by the LE response model. 上述公式 (1) 至 (5) 所描述的公式是基于 LE 响应模型对路面结构各点应力状态的精确计算。 Accounting for the nonuniformity of the contact pressure provides more accurate response estimates near surface in the HMA and base layers. 考虑到接触压力的不均匀性,可对 HMA 和基层的近表面进行更精确的响应估算。
11.2.6 Model Validation Against Measured Test Data 11.2.6 根据测量的测试数据验证模型
To show the validity of the PD model, comparisons were made between various model outputs and measured field data from the full-scale instrumented tests described in this report. 为了证明 PD 模型的有效性,对各种模型输出结果和本报告所述全尺寸仪器测试的现场测量数据进行了比较。 The model was validated against the rut-depth histories of each pavement section, along with the ISM histories and the measured EPC response histories at different depths. 根据每个路面断面的车辙深度历史记录、ISM 历史记录和不同深度的 EPC 响应测量历史记录对模型进行了验证。
Figure 120 shows comparisons of the rut-depth accumulation with traffic between the proposed PD model predictions and the measurements from the full-scale test sections constructed with the limestone base. 图 120 显示了拟议的 PD 模型预测结果与使用石灰岩路基建造的全尺寸试验路段测量结果之间的比较。 Good agreement can be seen throughout with the minor exception of the 2 in. HMA over limestone base with the 10 CBR subgrade. Interestingly, this test item performed nearly the same as the 4 in . HMA over limestone with 10 CBR subgrade. 除了石灰岩基层上的 2 英寸 HMA 和 CBR 值为 10 的基层略有不同之外,其他测试结果都非常吻合。有趣的是,该测试项目与石灰岩上的 4 英寸 HMA 和 10 CBR 基层的表现几乎相同。 Consequently, this performance was difficult to match closely with the model, because very similar parameters were used 因此,这一性能很难与模型密切匹配,因为所使用的参数非常相似
except for the difference in HMA thickness. In general, the PD model performed well in its rut-depth predictive capabilities. 除了 HMA 厚度的差异。总体而言,PD 模型的路辙深度预测能力表现良好。
Figure 120. Comparison of rut-depth history between model and full-scale test items. 图 120.模型与全尺寸测试项目的车辙深度历史比较。
Figure 121 compares model predictions of the vertical stress at the top of the base with those measured by the EPCs in the test sections. Given that the P-8 inflation pressure was 220 psi , the measured vertical stresses 2 in. from the top of the base layer were relatively high. 图 121 比较了模型对基底顶部垂直应力的预测值与 EPC 在试验段测得的垂直应力。考虑到 P-8 的充气压力为 220 psi,距离基层顶部 2 英寸处测得的垂直应力相对较高。 The response model using nonuniform contact pressure approximations coupled with the modulus deterioration model provided reasonable estimates of these measured pressures. 采用非均匀接触压力近似值的响应模型与模量劣化模型相结合,对这些测量压力进行了合理的估算。
The EPC measurements were reported at each discrete pass level up to 30 passes, and then the maximum EPC measurement was reported over a given interval (e.g., 100 passes, 300 passes, etc.). The first 30 passes show the effects of wander as one of the P-8 tires gets closer to the EPC of interest. Furthermore, beyond 30 passes the effects of modulus deterioration begin to manifest in the form of relatively greater EPC measurements. 在每个离散通过级别报告 EPC 测量值,直至 30 个通过级别,然后报告给定时间间隔(如 100 个通过级别、300 个通过级别等)内的最大 EPC 测量值。前 30 次测量显示了随着一个 P-8 轮胎越来越接近相关 EPC 而产生的游移效应。此外,超过 30 次后,模量劣化的影响开始以相对较大的 EPC 测量值的形式表现出来。 The PD model seems to account for these two difficult phenomena reasonably well. PD 模型似乎很好地解释了这两个困难的现象。
Figure 121. Comparison between predicted and measured vertical stress at the top of base. 图 121.底座顶部预测垂直应力与实测垂直应力的比较。
Figure 122 compares model predictions of the vertical stress at middepth of the base with those measured by the EPCs in the test sections. 图 122 比较了模型对基底中深处垂直应力的预测值与 EPC 在试验段测得的垂直应力。
Considering the variability of the material behavior and the complexity of matching stress history with repeated wandering traffic, the PD model does very well at predicting the middepth base EPC measured pressures. 考虑到材料行为的多变性以及应力历史与反复徘徊的交通相匹配的复杂性,PD 模型在预测中间深度基础 EPC 测量压力方面做得非常好。
Figure 122. Comparison between predicted and measured vertical stress at middepth of base. 图 122.基底中间深度处预测垂直应力与测量垂直应力的比较。
Figure 123 compares model predictions of the vertical stress at the top of the subgrade with those measured by the EPCs in the test sections. 图 123 比较了模型对路基顶部垂直应力的预测值与 EPC 在试验段测得的数值。 It is interesting to note that when originally developing the proposed PD model, estimates of the maximum vertical stress beyond 30 passes were approximately 40 psi using a uniform contact pressure assumption with no inclusion of a modulus deterioration-hardening model. 值得注意的是,在最初开发拟议的 PD 模型时,采用均匀接触压力假设,不包含模量劣化-硬化模型,对超过 30 道次的最大垂直应力的估计值约为 40 psi。 With the inclusion of the modulus deterioration-hardening model and nonuniform contact pressure approximation, the predicted subgrade stresses were significantly closer to those measured in the field. 加入模量劣化-硬化模型和非均匀接触压力近似值后,预测的路基应力明显更接近实地测量值。 Team members believed that the implementation of these two numerical procedures was instrumental in the overall efficacy of the PD model’s predictive capabilities. 小组成员认为,这两个数字程序的实施有助于提高预测发展模型的整体预测能力。
Figure 123. Comparison between predicted and measured vertical stress at top of the subgrade. 图 123.路基顶部预测垂直应力与实测垂直应力的比较。
Upon observing the relationship between the rut-depth progression, the EPC measured responses, and the ISM histories, it was apparent that the ability to approximate modulus deterioration and subsequent hardening with repeated load applications was significant. 通过观察车辙深度进展、EPC 测量响应和 ISM 历史记录之间的关系,可以明显看出,在反复施加载荷的情况下,模量劣化和随后硬化的近似能力非常重要。 To validate this model, an additional call was made to the LE response model each simulated HVS pass of the P-8 using the FWD load and geometry. During each call to the response model, only the vertical deflection beneath the load was evaluated. 为了验证该模型,在使用 FWD 载荷和几何形状模拟 P-8 的每次 HVS 通过时,都对 LE 响应模型进行了额外的调用。在每次调用响应模型时,只对载荷下方的垂直变形进行评估。 This provided an estimate of an ISM using the PD model to compare with the measured ISMs in each test item. Figure 124 shows that the two-part model provides a representative prediction of the true ISM behavior measured in the field tests. 这提供了使用 PD 模型的 ISM 估计值,可与每个测试项目中测得的 ISM 进行比较。图 124 显示,两部分模型对现场测试中测得的真实 ISM 行为进行了有代表性的预测。 More specifically, the bilinear model appears to capture the general trend of modulus deterioration and its corresponding transition to a hardened steady state. 更具体地说,双线性模型似乎捕捉到了模量劣化的总体趋势及其向硬化稳定状态的相应过渡。
Figure 124. Comparison between model predictions and ISM histories. 图 124.模型预测值与 ISM 历史数据的比较。
The parameters in the PD model were required to be calibrated to the local materials used in full-scale testing. The calibration process was conducted against observed material behavior in laboratory and field testing. PD 模型中的参数需要根据全面测试中使用的当地材料进行校准。校准过程是根据实验室和现场测试中观察到的材料行为进行的。 Once the parameters were calibrated, these parameters remained constant throughout the validation testing against the full-scale instrumented test data. The parameters used for the PD model are provided in Table 25. 参数校准后,这些参数在根据全尺寸仪器测试数据进行验证测试的整个过程中保持不变。表 25 提供了用于 PD 模型的参数。 While it is important to understand that the model still requires exposure to other pavement material types, the parameters used in this study in Table 25 are very close to the global parameters produced by the MEPDG (Witczak and El-Basyouny 2004). 虽然必须了解该模型仍需要接触其他路面材料类型,但表 25 中本研究使用的参数非常接近 MEPDG 生成的全球参数(Witczak 和 El-Basyouny,2004 年)。
Table 25. Calibrated parameters used in PD model for simulations against full-scale test data. 表 25.根据全尺寸测试数据模拟 PD 模型时使用的校准参数。
11.2.7 Development of Contingency Flexible Pavement Design Curves 11.2.7 制定应急柔性路面设计曲线
The adequacy of the PD model to predict flexible pavement performance was validated against measured rutting performance and instrumentation response data. 通过测量车辙性能和仪器响应数据,验证了 PD 模型是否足以预测柔性路面性能。 Thereafter, the validated PD model was used to predict pavement performance for material properties outside those evaluated in this experiment. 此后,经过验证的 PD 模型被用于预测本实验所评估材料特性之外的路面性能。
An analysis was conducted to calculate the passes to failure for a variety of material properties including various HMA pavement thicknesses, base course thicknesses, and subgrade CBR values. 对各种材料特性进行了分析,包括不同的 HMA 路面厚度、基层厚度和基层 CBR 值,以计算故障通过率。 Separate analyses were conducted for HMA thicknesses of 2 in., 4 in., and 6 in.; these values were representative of HMA thicknesses expected to be realistic for contingency construction efforts. Additionally, a range of subgrade CBR values ( 4CBR,6CBR,8CBR4 \mathrm{CBR}, 6 \mathrm{CBR}, 8 \mathrm{CBR}, 10 CBR , and 15 CBR ) were analyzed as representative of anticipated subgrade CBR values. Finally, base course thicknesses ranging from a minimum of 4 in . to a maximum of 24 in. were analyzed in 2 in. increments. 分别对 2 英寸、4 英寸和 6 英寸的 HMA 厚度进行了分析;这些值代表了应急施工中预期的实际 HMA 厚度。此外,还分析了一系列基层 CBR 值( 4CBR,6CBR,8CBR4 \mathrm{CBR}, 6 \mathrm{CBR}, 8 \mathrm{CBR} 、10 CBR 和 15 CBR),以代表预期的基层 CBR 值。最后,以 2 英寸为增量,分析了从最小 4 英寸到最大 24 英寸的基层厚度。 The calculated passes to failure were used to develop a series of designs curves for each HMA pavement thickness (Figure 125 to Figure 127). The design curves are based on a minimum 70 CBR base course strength and are valid for expeditionary designs <= 1,000\leq 1,000 P-8 passes. 计算出的失效通过率用于为每种 HMA 路面厚度制定一系列设计曲线(图 125 至图 127)。这些设计曲线基于最低 70 CBR 的基层强度,适用于远征设计 <= 1,000\leq 1,000 P-8 通过量。
To utilize the design curves, some design parameters should be preselected. First, the HMA thickness should be selected such that the appropriate family of curves is utilized. Additionally, the anticipated or “design” passes to failure should be known. 要使用设计曲线,应预先选择一些设计参数。首先,应选择 HMA 厚度,以便使用适当的曲线系列。此外,还应该知道预期或 "设计 "的失效通过量。 The appropriate design chart is then entered on the xx-axis (passes to failure) and a vertical line is drawn to intersect the appropriate subgrade CBR value. A horizontal line is then drawn from the intersection of passes-to-failure and subgrade CBR to the yy-axis (base thickness). 然后在 xx 轴(塌落度)上输入相应的设计图表,并绘制一条垂直线与相应的基层 CBR 值相交。然后从坍塌通过率和基层 CBR 的交叉点到 yy 轴(基层厚度)之间绘制一条水平线。
The design charts can be used to determine the impact of changing the HMA thickness on required base course thickness for various subgrade CBR values such that local material availability and cost/construction benefit can be analyzed by the designer. 设计图表可用于确定改变 HMA 厚度对不同基层 CBR 值所需基层厚度的影响,以便设计人员分析当地材料的可用性和成本/施工效益。
The results of the full-traffic test from this experiment were plotted on the design curves and are shown in Figure 128. In general, the data plot to the right of the respective subgrade CBR values. 该实验的全流量测试结果绘制在设计曲线上,如图 128 所示。一般来说,数据绘制在相应的基层 CBR 值的右侧。 This was expected, because the test items contained a base course CBR exceeding 70 CBR, and more passes to failure would be expected. 这在意料之中,因为测试项目中的基层 CBR 超过 70CBR,预计会有更多的通过率。 Further, the data plot near the respective subgrade CBR curves, suggesting that the developed design methodology adequately predicts anticipated performance. 此外,数据曲线接近相应的基层 CBR 曲线,表明所开发的设计方法能够充分预测预期性能。
The various design curves can be used to evaluate the impact of changing HMA thickness on the selected base course thickness. Simply, each curve can be entered with the same passes to failure and the same subgrade CBR strength, and a different base course thickness selected. 各种设计曲线可用于评估改变 HMA 厚度对所选基层厚度的影响。只需在输入每条曲线时,输入相同的塌方通过量和相同的基层 CBR 强度,并选择不同的基层厚度即可。 An example is shown in Figure 129. In this case, 500 passes to failure were selected and a subgrade CBR of 9 was selected. For a 2 in. thick HMA layer, a minimum 15 in . thick base course is required. For a 4 in. thick HMA layer, a minimum 12 in. 图 129 是一个例子。在这种情况下,选择了 500 次碾压至破坏,并选择了 9 的基层 CBR。对于 2 英寸厚的 HMA 层,至少需要 15 英寸厚的基层。对于 4 英寸厚的 HMA 层,至少需要 12 英寸厚的基层。 thick base course is required, and for a 6 in. thick HMA layer, a 9 in. thick base course is required. Thus, in the case of the parameters selected for the example, an additional 2 in . of HMA results in an approximate 3 in . reduction in base course thickness. 对于 6 英寸厚的 HMA 层,需要 9 英寸厚的基层。因此,在示例所选参数的情况下,增加 2 英寸的 HMA 会导致基层厚度减少约 3 英寸。
Figure 128. Results of APT experiment in relation to design curves. 图 128.与设计曲线相关的 APT 实验结果。
A full-scale accelerated pavement test section was constructed with the primary objective of determining minimum thickness requirements for the P-8 Poseidon aircraft for contingency operations (approximately 500 passes). 我们建造了一个全尺寸加速路面试验段,主要目的是确定 P-8 海神飞机在应急行动中的最小厚度要求(约 500 次)。 A series of rigid and flexible pavement test items with varying layer thicknesses and material properties were trafficked with ERDC’s HVS to provide multiple pass level data points. The results of the experiment yielded the following conclusions: 使用 ERDC 的 HVS 对一系列具有不同层厚和材料特性的刚性和柔性路面进行了测试,以提供多个通过级数据点。实验结果得出以下结论:
12.1 Rigid Pavement Test Conclusions 12.1 硬质路面试验结论
Analysis of the rigid pavement test results yielded the following conclusions for the P-8 aircraft at maximum operational weight: 对刚性路面测试结果进行分析后,得出了 P-8 飞机在最大运行重量下的以下结论:
The 8 in. thick PCC sustained 400 passes to the first crack, 2,500 passes to a shattered slab condition, and 7,500 passes to complete failure. The 11 in. thick PCC sustained 50,000 passes with no distress identified. 8 英寸厚的 PCC 在出现第一条裂缝时承受了 400 次冲击,在板破碎时承受了 2,500 次冲击,在完全损坏时承受了 7,500 次冲击。11 英寸厚的 PCC 承受了 50,000 次冲击,未发现任何问题。 Thus, there was a significant observed performance difference between an 8 in. thick slab thickness and an 11 in. thick slab thickness. 因此,8 英寸厚的板和 11 英寸厚的板之间存在明显的性能差异。
Cracking was not observed on the dowelled transverse joint of the 8 in. thick PCC pavement until approximately 7,500 passes compared to 500 passes on the undowelled transverse joint. 在 8 英寸厚的 PCC 路面上,直到大约 7,500 次通过后才观察到裂缝,而未通过 500 次的横向接缝则观察到裂缝。 Thus, rigid pavements with fully dowelled transverse joints would be expected to sustain more passes to failure than rigid pavements with undowelled joints. 因此,横向接缝处完全打钉的刚性路面,预计比接缝处未打钉的刚性路面承受更多的破坏。
ISM values in the 8 in. thick PCC tended to decrease with an increase in traffic and observed deterioration (cracking). ISM values in the 11 in. thick PCC remained relatively consistent throughout traffic; this was consistent with the lack of visual deterioration. 8 英寸厚 PCC 中的 ISM 值随着交通量的增加和观察到的老化(开裂)而呈下降趋势。11 英寸厚 PCC 中的 ISM 值在整个交通过程中保持相对稳定;这与未出现视觉劣化是一致的。
Subgrade pressure response data trended upward with an increase in traffic in the 8 in. thick PCC, while the subgrade pressure response values in the 11 in . thick PCC were much lower and relatively consistent throughout traffic application. These data suggest that the 11 in. 8 英寸厚 PCC 的路基压力响应数据随着交通量的增加而呈上升趋势,而 11 英寸厚 PCC 的路基压力响应值要低得多,并且在整个交通应用过程中相对稳定。这些数据表明,11 英寸厚 PCC 的路基压力响应值比 8 英寸厚 PCC 低得多。 thick PCC was sufficiently thick to limit observed pressure occurring near the top of the subgrade. 厚的 PCC 厚度足以限制在接近路基顶部时产生的观测压力。
SSG data tended to show a general increase with increases in traffic; however, limited data were available due to gauge failures early in traffic. Thus, no general trafficking conclusions can be drawn from this data. SSG 数据显示,随着交通流量的增加,SSG 数据也普遍增加;但是,由于交通流量初期的仪表故障,可获得的数据有限。因此,无法从这些数据中得出普遍的交通量结论。
ESG data in the 8 in. thick PCC trended upward around 300 passes, which was slightly prior to the point at which the first visual crack was 8 英寸厚 PCC 中的 ESG 数据在 300 次左右呈上升趋势,略早于出现第一条可视裂缝的时间点。
identified. These data suggest that internal deterioration occurred prior to visual confirmation. Increases in ESG response were observed near 1,000 passes in the 11 in. thick PCC; however, a visual inspection did not identify surface cracking at traffic conclusion. 已确认。这些数据表明,在目测确认之前就已经出现了内部损坏。在 11 英寸厚的 PCC 中,观察到 ESG 响应在接近 1,000 次通过时有所增加;但是,目测检查并未发现交通结束时的表面裂缝。
12.2 Minimum Contingency Recommendations for Rigid Pavements 12.2 硬质路面最低应急建议
The results of the traffic tests found that existing DoD rigid pavement design criteria is overly conservative-existing criteria overpredicts the required concrete thickness to support P-8 operations. 交通测试结果表明,现有的国防部刚性路面设计标准过于保守--现有标准过高地预测了支持 P-8 行动所需的混凝土厚度。 This conservatism becomes more significant for design of rigid pavements for contingency operations. Thus, it is recommended that the minimum contingency rigid pavement cross section meet the requirements shown in Figure 130. 在设计应急刚性路面时,这种保守性变得更加重要。因此,建议最小应急刚性路面横截面满足图 130 所示的要求。 The recommended cross section and material properties are based on observations made during the full-scale traffic tests. 建议的横截面和材料特性是根据全面交通测试的观察结果确定的。 Further, engineering judgment was used to reduce material strength requirements for contingency requirements below that required in standard airfield pavement design. 此外,还利用工程判断将应急要求的材料强度要求降至低于标准机场路面设计的要求。 Thus, materials not meeting the minimum thickness and strength properties recommended herein would be expected to sustain a reduced number of P-8\mathrm{P}-8 operations. 因此,不符合此处推荐的最小厚度和强度特性的材料预计将减少 P-8\mathrm{P}-8 操作次数。
12.3 Flexible Pavement Test Conclusions 12.3 柔性路面试验结论
Analysis of the flexible pavement test results yielded the following conclusions for the P-8 aircraft at maximum operational weight: 对柔性路面测试结果进行分析后,得出了 P-8 飞机在最大运行重量下的以下结论:
Rutting performance data indicated that a competent base layer is required to sustain a reasonable number of P-8 operations. Further, 车辙性能数据表明,要维持合理数量的 P-8 作业,需要一个合格的基层。此外、
increased HMA thickness tended to improve rutting performance on a weaker subgrade. On a stiffer subgrade, rutting performance was less sensitive to HMA thickness for the small range of asphalt thickness examined in this study. 在较软弱的基层上,增加 HMA 厚度往往会改善车辙性能。在较硬的路基上,在本研究考察的较小沥青厚度范围内,车辙性能对 HMA 厚度的敏感性较低。
Initial ISM values were generally capable of identifying differences among the various test items. However, ISM values tended to converge with increased trafficking, except for the 4 in. thick HMA over LS over 10 CBR test item. These data indicated that a minimum 4 in. 最初的 ISM 值通常能够确定不同测试项目之间的差异。不过,除了 4 英寸厚的 HMA 碾压 LS 超过 10 CBR 的测试项目外,ISM 值往往随着碾压量的增加而趋于一致。这些数据表明,最小 4 英寸 HMA 厚度应大于 10 CBR。 thick HMA layer over a competent base and a relatively stiff subgrade are required to support a meaningful number of P-8\mathrm{P}-8 operations. 要支持一定数量的 P-8\mathrm{P}-8 操作,需要在合格的基础和相对坚硬的基层上铺设较厚的 HMA 层。
Subgrade vertical pressure response measurements indicated that an increase in HMA thickness resulted in a reduction in measured vertical pressure. Similarly, inclusion of a competent base layer resulted in reductions in measured subgrade vertical pressure response. 基层垂直压力响应测量结果表明,增加 HMA 厚度会导致测得的垂直压力降低。同样,加入适当的基层也会降低测得的路基垂直压力响应。
The top of base vertical pressure response data indicated that in the 2 in. thick HMA section measured vertical pressure was less in the case of a 10 CBR subgrade. A comparison of the 4 in . 基底顶部垂直压力响应数据表明,在 2 英寸厚的 HMA 断面上,CBR 值为 10 的基底测得的垂直压力较小。4 英寸厚 HMA 路面的比较 thick HMA top of base vertical pressure response data indicated that average measured vertical pressure was statistically equivalent suggesting that subgrade CBR did not have a significant effect on top of base vertical pressure with a thicker HMA layer. 厚 HMA 基底顶面垂直压力响应数据表明,测得的平均垂直压力在统计上是相等的,这表明在 HMA 层较厚的情况下,基层 CBR 对基底顶面垂直压力的影响并不明显。
Increases in HMA thickness tended to impact middepth measured base vertical pressure response more on the 10 CBR subgrade than the 6 CBR subgrade. 与 6 CBR 路基相比,HMA 厚度的增加往往会对 10 CBR 路基的中间深度测量基底垂直压力响应产生更大影响。 An increase in HMA thickness resulted in an average difference of approximately 30 psi on 10 CBR subgrade, compared to an average difference of approximately 6 psi on 6 CBR subgrade. 增加 HMA 厚度后,10 CBR 基层的平均差异约为 30 psi,而 6 CBR 基层的平均差异约为 6 psi。
Single-depth deflectometer response data indicated that the largest dynamic and permanent deflections at the subgrade were observed in the gravel base test items, further confirming the importance of a competent aggregate base layer. 单深度挠度仪响应数据表明,在砾石基层测试项目中观察到的基层动态挠度和永久挠度最大,这进一步证实了合格集料基层的重要性。 SDD response data generally followed expected trends; an increase in HMA thickness, increase in base layer strength, or an increase in subgrade CBR resulted in a reduction in both dynamic and permanent subgrade deflection. SDD 响应数据一般遵循预期趋势;HMA 厚度增加、基层强度增加或基层 CBR 增加都会导致基层动态和永久挠度减小。
ASG measurements generally indicated that on a weaker subgrade, an increase in HMA thickness resulted in a decrease in strain values. On a firmer subgrade HMA thickness was not found to have an impact on measured strain values. ASG 测量结果普遍表明,在较软弱的路基上,增加 HMA 厚度会导致应变值降低。在较坚实的路基上,HMA 厚度不会对测出的应变值产生影响。
A forensic investigation of the HMA test items generally confirmed observations made during trafficking. Posttraffic elevation measurements indicated that primary deformation occurred in the 对 HMA 测试项目进行的取证调查基本证实了贩运期间的观察结果。交通后的标高测量结果表明,主要变形发生在
gravel base; however, for the limestone base test items, primary deformation occurred in the subgrade. 然而,对于石灰岩基层测试项目,主要变形发生在基层。
12.4 Minimum Contingency Recommendations for Flexible Pavements 12.4 柔性路面最低应急建议
The results of the traffic tests found that existing flexible pavement design models were not adequate for contingency pavement performance predictions for the P-8 aircraft. 交通测试结果表明,现有的柔性路面设计模型不足以预测 P-8 飞机的应急路面性能。 Thus, it is recommended that the minimum contingency flexible pavement cross section meet the requirements shown in Figure 131. These recommendations are based on the results of the full-scale traffic experiments. 因此,建议最小应急柔性路面横截面满足图 131 所示的要求。这些建议是根据全尺寸交通实验结果提出的。 Further, the traffic results indicated that the performance of a flexible pavement section was highly sensitive to base course strength. 此外,交通结果表明,柔性路面的性能对基层强度非常敏感。 Thus, flexible pavements containing base course materials not meeting the minimum strength requirements would be expected to have considerably less passes to failure. 因此,含有不符合最低强度要求的基层材料的柔性路面,其失效通过率会大大降低。
The results of the full-scale flexible pavement experiment were utilized to support an analytical modeling effort to extend flexible pavement thickness recommendations beyond those evaluated. 全尺寸柔性路面试验的结果被用来支持分析建模工作,以将柔性路面厚度建议扩展到评估范围之外。 As a result, a series of design curves were developed to allow a designer flexibility in determining pavement thickness recommendations. 因此,设计人员开发了一系列设计曲线,以便灵活确定路面厚度建议。
Analysis of the ADR test results yielded the following conclusions: 对 ADR 测试结果的分析得出以下结论:
The ADR repair techniques were found to be generally compatible with a P-8 aircraft except for the FRP surface over a geosynthetic reinforced sand, which sustained only a limited number of aircraft passes. 研究发现,ADR 修复技术总体上与 P-8 飞机兼容,但玻璃钢表面覆盖土工合成材料加固砂除外,因为后者只能承受有限次数的飞机通过。
Repairs surfaced with a FRP could sustain a meaningful number of P-8 passes without any observable mat breakage and/or tearing. 用玻璃纤维增强塑料表面进行的修复可以承受一定次数的 P-8 试验,而不会出现任何明显的垫层破损和/或撕裂。
Cementitious-based repairs could sustain a meaningful number of P-8 passes. 以水泥基为基础的修补材料可以承受一定次数的 P-8 试验。
The stone and grout surfaced repair exceeded the 500-pass contingency threshold. However, the repair was not capable of sustaining a sustainment level of P-8\mathrm{P}-8 passes. 石材和灌浆表面的修复超过了 500 次应急阈值。但是,该修复工程无法维持 P-8\mathrm{P}-8 通过的持续水平。
A summary of passes to failure for the ADR repair techniques is shown in Table 26. 表 26 列出了 ADR 修复技术的故障通过率汇总。
Table 26. ADR passes to failure. 表 26.ADR 通过失败。
维修编号
Repair
Number
Repair
Number| Repair |
| :---: |
| Number |
Surface 表面
Backfill 回填
Subgrade 基层
通过失败
Passes to
Failure
Passes to
Failure| Passes to |
| :--- |
| Failure |
*Repair technique did not achieve failure; traffic halted at 3,500 passes * 修复技术没有实现故障;交通在 3 500 个山口处停止
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Appendix A: 8 in. Thick PCC Data 附录 A:8 英寸厚 PCC 数据厚 PCC 数据
W. Jeremy Robinson, Jeremiah M. Stache, Jeb. S. Tingle, Carlos R. Gonzalez, Anastasios M. Ioannides, and James T. Rushing
6. AUTHOR(S)
W. Jeremy Robinson, Jeremiah M. Stache, Jeb. S. Tingle, Carlos R. Gonzalez, Anastasios M. Ioannides, and James T. Rushing| 6. AUTHOR(S) |
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| W. Jeremy Robinson, Jeremiah M. Stache, Jeb. S. Tingle, Carlos R. Gonzalez, Anastasios M. Ioannides, and James T. Rushing |
} {6.AUTHOR(S) W. Jeremy Robinson, Jeremiah M. Stache, Jeb.S. Tingle, Carlos R. Gonzalez, Anastasios M. Ioannides, and James T. Rushing }
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Geotechnical and Structures Laboratory US Army Engineer Research and Development Center 3909 Halls Ferry Road Vicksburg, MS 39180-6199
7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS
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| Geotechnical and Structures Laboratory US Army Engineer Research and Development Center 3909 Halls Ferry Road Vicksburg, MS 39180-6199 |
8.执行机构报告编号 ERDC/GSL TR-23-4
8. PERFORMING ORGANIZATION REPORT NUMBER
ERDC/GSL TR-23-4
8. PERFORMING ORGANIZATION REPORT NUMBER
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Naval Facilities Engineering and Expeditionary Warfare Center (NAVFAC EXWC) 1100 23rd Ave.
Port Hueneme, CA 93043
Naval Facilities Engineering and Expeditionary Warfare Center (NAVFAC EXWC) 1100 23rd Ave.
Port Hueneme, CA 93043| Naval Facilities Engineering and Expeditionary Warfare Center (NAVFAC EXWC) 1100 23rd Ave. |
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1. REPORT DATE (DD-MM-YYYY) March 2023 2. REPORT TYPE Final 3. DATES COVERED (From - To)
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| Naval Facilities Engineering and Expeditionary Warfare Center (NAVFAC EXWC) 1100 23rd Ave. <br> Port Hueneme, CA 93043 | | 10. SPONSOR/MONITOR'S ACRONYM(S) 11. SPONSOR/MONITOR'S REPORT NUMBER(S) |
DISTRIBUTION / AVAILABILITY STATEMENT 分发/供应声明
DISTRIBUTION STATEMENT A. Approved for public release; distribution is unlimited. 发行说明 A. 批准公开发行;发行不受限制。
13. SUPPLEMENTARY NOTES 13.补充说明
Funding Account Code B36399 资金账户代码 B36399
14. ABSTRACT 14.摘要
A full-scale airfield pavement test section was constructed and trafficked by the US Army Engineer Research and Development Center to determine minimum rigid and flexible pavement thickness requirements to support contingency operations of the P-8 Poseidon aircraft. 美国陆军工程研发中心建造了一个全尺寸的机场路面试验段,并进行了交通测试,以确定最低刚性和柔性路面厚度要求,为 P-8 海神飞机的应急行动提供支持。 Additionally, airfield damage repair solutions were tested to evaluate the compatibility of those solutions with the P-8 Poseidon. 此外,还测试了机场损坏修复解决方案,以评估这些解决方案与 P-8 海神的兼容性。 The test items consisted of various material thickness and strengths to yield a range of operations to failure allowing development of performance predictions at a relatively lower number of design operations than are considered in traditional sustainment pavement design scenarios. 测试项目包括不同的材料厚度和强度,以产生一系列失效操作,从而在设计操作次数相对少于传统养护路面设计情况下的情况下进行性能预测。 Test items were trafficked with a dual-wheel P-8 test gear on a heavy-vehicle simulator. Flexible pavement rutting, rigid pavement cracking and spalling, instrumentation response, and falling-weight deflectometer data were monitored at select traffic intervals. 在重型车辆模拟器上使用双轮 P-8 测试装置进行测试。在选定的行车间隔时间内,对柔性路面车辙、刚性路面开裂和剥落、仪器响应以及落重挠度计数据进行了监测。 The results of the trafficking tests indicated that existing design predictions were generally overconservative. Thus, minimum pavement layer thickness recommendations were made to support a minimum level of contingency operations. 贩运测试结果表明,现有的设计预测普遍过于保守。因此,提出了最小路面层厚度建议,以支持最低水平的应急运行。 The results of full-scale flexible pavement experiment were utilized to support an analytical modeling effort to extend flexible pavement thickness recommendations beyond those evaluated. 利用全尺寸柔性路面实验结果来支持分析建模工作,以将柔性路面厚度建议扩展到评估范围之外。
17. LIMITATION
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19a. NAME OF RESPONSIBLE PERSON 19a.负责人姓名
19b. TELEPHONE NUMBER (include area code) 19b.电话号码(包括区号)
Prepared for Naval Facilities Engineering and Expeditionary Warfare Center (NAVFAC EXWC) 1100 23rd Ave. 为海军设施工程和远征作战中心 (NAVFAC EXWC) 编写,地址:1100 23rd Ave.
Port Hueneme, CA 93043 加利福尼亚州韦内姆港 93043
^(1){ }^{1} For a full list of the spelled-out forms of the units of measure used in this document, please refer to US Government Publishing Office Style Manual, 31st ed. (Washington, DC: US Government Publishing Office, 2016), 248-252, https://www.govinfo.gov/content/pkg/GPO-STYLEMANUAL-2016/pdf/GPO-STYLEMANUAL-2016.pdf. ^(1){ }^{1} 有关本文件中使用的计量单位的拼写形式的完整列表,请参阅《美国政府出版办公室文体手册》第 31 版(华盛顿特区:美国政府出版办公室,2016 年),248-252,https://www.govinfo.gov/content/pkg/GPO-STYLEMANUAL-2016/pdf/GPO-STYLEMANUAL-2016.pdf。
^(1){ }^{1} Bell, H. P., W. D. Carruth, J. W. Fisher, J. L. Daugherty, L. Garcia, A. B. Ward, W. C. Floyd, L. Edwards, J. S. Tingle, J. R. Davis, J. F. Rowland, C. R. Lloyd, and T. T. Henderson. (In draft). ^(1){ }^{1} Bell, H. P., W. D. Carruth, J. W. Fisher, J. L. Daugherty, L. Garcia, A. B. Ward, W. C. Floyd, L. Edwards, J. S. Tingle, J. R. Davis, J. F. Rowland, C. R. Lloyd, and T. T. Henderson.(草稿)。 Expedient and Expeditionary Airfield Damage Repair (E-ADR) Joint Capability Technology Demonstration (JCTD). Vicksburg, MS: US Army Engineer Research and Development Center. 快速和远征机场损伤修复 (E-ADR) 联合能力技术演示 (JCTD)。密歇根州维克斯堡:美国陆军工程研发中心。