降雨条件下非饱和朗肯土压力统一解

Unified Solution of Rankine's Earth Pressure of Unsaturated Soil Under Rainfall

基于统一强度理论和Bishop有效应力原理,结合降雨入渗解析解,推导了考虑中间主应力效应及材料拉压比影响的降雨条件下非饱和朗肯土压力的统一解。通过算例验证了推导公式的有效性,并探讨了降雨条件下基质吸力的变化对非饱和土压力的影响。结果表明:主动土压力随着统一强度理论参数的增大而减小,而被动土压力呈现相反趋势;随着降雨的发生、浸润和停止,主动土压力和被动土压力呈现不稳定变化,最终都趋于稳定,这是由基质吸力的变化所引起的;非饱和渗透特征参数的选取会对土压力的计算产生显著影响。

Based on the unified strength theory and the principle of effective stress of Bishop, combining with rainfall infiltration analytic solution, the unified solution of Rankine＇s earth pressure formula of unsaturated soil under rainfall condition was established with taking the effect of the intermediate principal stress and material tension-pressure ratio into account. The availability was verified by an example, and the influence of matric suction during rainfall was discussed. The results indicate that with the increase of the unified strength theory parameters, the active earth pressure decreases, whereas the passive earth pressure shows the opposite trend. In the wake of the occurrence, infiltration and end of rainfall, the earth pressure presents a tendency of unstable variation but finally stabilizes, which is caused by the change of matric suction during rainfall. The parameter of soil permeability character will significantly influence the earth pressure.