考虑土拱效应的挡土墙被动土压力分析

基于库伦土压力理论,假定被动极限状态下挡土墙后大主应力拱迹线为抛物线,考虑土拱效应,推导了被动土压力系数的理论公式,并将其用于水平微分单元法,分析土体处于被动极限平衡状态时的应力状态,得到平动模式下被动土压力强度、合力及合力作用点的计算公式;在此基础上,分析了内摩擦角及墙面摩擦角对被动土压力系数、土压力强度及合力作用点的影响,并与库伦土压力理论等已有方法和模型试验数据进行了对比分析,验证了该计算方法的合理性。

Analysis on Passive Earth Pressure for Retaining Walls Considering Soil Arching

Based on Coulomb's earth pressure theory,assuming the trace of the major principal stress arching as a parabola,and considering arch effects,the theory formula is obtained including the lateral coefficient of passive earth pressures.And by using the coefficient in the method of horizontal differential element to analyse the stess conditions of soil on passive limiting equilibrium,the theoretical formulae for unit earth pressures,the resultant earth pressures and the application points of the resultant earth preesures on translation mode are obtained.On this basis,the effects of the internal friction angle and wall friction angle on the lateral coefficients of earth pressures,the unit earth pressures,and the application points of the resultant forces are investigated and analyzed.The method presented here is compared with the exiting methods and some experimental data,verifying the rationality of the method.