挡土墙主动土压力极限上限分析

Upper bound limit analysis of active earth pressure on retaining wall

为了计算墙背倾斜粗糙、填土面倾斜且作用均布荷载条件下的挡土墙主动土压力,采用摩尔-库仑屈服准则,建立三角形破坏机构,推导了挡土墙主动土压力上限解计算公式,使用粒子群算法搜索最危险滑裂面并获得主动土压力最优解.通过与经典朗肯土压力理论和模型试验结果对比分析可知:该计算方法包含了朗肯土压力理论并与模型试验实测结果比较符合.在此基础上分析了墙背倾角、填土面倾角、墙土外摩擦角和填土内摩擦角对滑裂面倾角和主动土压力系数的影响规律,相关计算数据可用于工程计算.

In order to calculate the active earth pressure on rough and inclined retaining wall when considering the influence of uniform load and slope angle of backfill,the upper bound solution formula based on Mohr-Coulomb yield criterion and triangular failure mechanism was suggested.The particle swarm algorithm was used to search the most dangerous sliding surface and the optimal solution of active earth pressure,and then the upper bound solutions were compared with the classical Rankine theory and model test.Results show that the Rankine theory is a special case of this calculation theory and the calculation results are well agreed with model test.On this basis,the influences of wall back inclination and slope angle of backfill,external friction angle between retaining walls and soil,internal friction angle to sliding surface inclination and active earth pressure coefficient were analyzed,which can be used for the design of retaining walls.