基于粒子群算法的粘性土主动土压力计算方法

Computation Method of Active Earth Pressure of Cohesive Soil Based on Particle Swarm Optimization

假定挡土墙后滑动面为库伦平面滑裂面,基于能量法,推导出了适合与砂性土与粘性土的主动土压力计算公式,然后引入粒子群智能优化算法,对最危险滑动面所对应的破裂角在变量范围内进行全局搜索。运用本文方法分别对墙后填土为为砂性土和粘性土的挡土墙土压力进行计算,发现对于砂性土,优化方法得到的破裂角与理论精确解完全一致;对于粘性土,方法计算结果与实测结果相对误差为5.5%。

Assuming the sliding surface behind retaining wall is Coulomb plane slip surface,an analytical calculation formulation of active earth pressure is derived by using energy method.This computation expression is applied for sandy soil and cohesive soil.Then sliding angle corresponding to the most dangerous slip surface is optimized in global search by using particle swarm optimization（PSO） algorithm.By applying the proposed approach,retaining wall earth pressure is calculated respectively when the filling soil behind retaining wall is sandy soil and cohesive soil.Results show that for sandy soil the sliding angle calculated by PSO algorithm matches exactly well with theoretical result,while for cohesive soil the calculated sliding angle has relative error of 5.5% with experimental result.