筒形挡土墙主动土压力的离散元数值模拟  

Discrete Element Analysis of Active Earth Pressure against the Cylindrical Wall

作　　者：陈国舟[1] 周国庆[1] 

机构地区：[1]中国矿业大学深部岩土力学与地下工程国家重点实验室,江苏徐州221008

出　　处：《地下空间与工程学报》2013年第S2期1848-1852,共5页Chinese Journal of Underground Space and Engineering

基　　金：国家重点基础研究发展计划(2012CB026103)

摘　　要：采用PFC3D颗粒流软件对筒形挡土墙主动土压力进行了数值模拟,得到了筒形挡土墙主动土压力随墙体位移的变化规律,分析了墙-土摩擦角对土压力的影响,并研究了筒形挡墙位移过程中墙周土体的应力分布,接触力变化等细观因素。结果表明:作用在筒形挡土墙上的土压力随着墙体位移的增加,土压力逐渐减小,最后趋于定值。土中环向应力随着距挡土墙距离的增大而增大,其最大值为初始环向应力的1.14倍,达到一定距离后逐渐减小并趋于初始应力值;径向应力则随着距挡土墙距离的增大而增大,但其值小于初始应力值,最后趋于初始应力值。对墙-土摩擦角的影响进行了分析,得出墙-土摩擦角增大,有利于竖向拱效应的发挥。并将本文所得数值模拟结果与现有筒形挡土墙土压力理论解进行了比较。The commercial program PFC3Dwas used to determine the spatial earth pressure of sand on cylindrical wall with respect to their deformation for different wall-soil interaction friction angle and soil internal friction angle.The microscopic parameter such as the stress in the soil and the contact force were studied during the wall deformation. The results show that the active earth pressure on the cylindrical wall decreases with the increase of displacement of the cylindrical wall and at last keeps constant. The circumferential stress increases with the increase of the radial distance from the wall surface until the distance reaching 4 /3times of the initial one,then decreases to the initial stress. The radial stress increases with the increase of radial distance from the wall surface until the stress is equal to the initial stress. The parameter of the wall-soil interaction friction angle is analyzed which indicates that the increase of wall-soil interaction friction angle enhances the influence of the vertical soil arching. The numerical results are compared against the previously published theoretical solutions.

关 键 词：颗粒流 筒形挡土墙 主动土压力 竖向拱效应 

分 类 号：TU476.4[建筑科学—结构工程] TU432[建筑科学—土工工程]