Numerical analysis of crack generation within embankment built on expansive soil foundation  

膨胀土地基上路堤裂缝形成数值分析（英文）

作　　者：程永振[1] 黄晓明[1] 李昶[1] 李连友[2] 

机构地区：[1]东南大学交通学院,南京210096 [2]中国路桥工程有限责任公司科技部,北京102600

出　　处：《Journal of Southeast University(English Edition)》2017年第2期224-229,共6页东南大学学报（英文版）

基　　金：The National Natural Science Foundation of China(No.51378121)

摘　　要：In order to analyze the initial cracking behavior of highway embankment in the regions of expansive soil, the changes in peaks of tensile stress and their location on top of the embankment for a typical highway embankment section were simulated by ABAQUS. The simulation results indicate that the matric suction was a concave distribution on top of the expansive soil foundation and that it induced differential deformation of foundation and embankment. The peaks of tensile stress on top of the embankment are not located at a fixed site, but gradually move towards the shoulder following the evaporation duration. When the evaporation intensity is larger, the peak of tensile stress on top of embankment increases at a faster rate following the evaporation duration,and its location is closer to the shoulder. The thicker expansive soil layer helps the peaks of tensile stress to reach the critical tensile stress quickly, but the embankment cannot crack when the expansive soil layer is no more than 1.5m after 30d soil surface evaporation; the higher the embankment, the smaller the peak of tensile stress occurring on top of the highway embankment, and its location will be further away from the shoulder. Therefore, a higher embankment constructed on a thinner expansive soil layer can reduce the crack generation within the highway embankment.为了分析膨胀土地区路堤初始开裂行为,使用ABAQUS模拟了典型路基断面的路堤顶部张拉应力峰值和峰值位置的改变.模拟结果表明:基质吸力在膨胀土地基顶部呈凹形分布,并且引起了地基和路堤的不均匀变形.路堤顶部张拉应力峰值并非位于某一固定点,而是随着蒸发的持续逐渐朝路肩移动.蒸发强度越大,随着地表蒸发的进行,路堤顶面张拉应力峰值增大越快,其位置越靠近路肩;厚层膨胀土有助于路堤顶面张拉应力峰值快速到达其抗拉强度阈值,而膨胀土厚度小于1.5m时,地表蒸发30天,路堤不会开裂;路堤越高,路堤顶面张拉应力峰值越小,其位置越远离路肩.因此,薄层膨胀土土层上修筑较高路堤可以减少路堤裂缝的形成.

关 键 词：expansive soil foundation soil shrinkage CONSOLIDATION tensile stress embankment cracks 

分 类 号：U416[交通运输工程—道路与铁道工程]