考虑剪应力作用的有限土体被动土压力分析

以挡土墙后有限范围砂土为研究对象，建立挡土墙位移与内、外摩擦角的关系，假定墙后土体为圆弧形拱，并考虑层间剪应力，采用多道滑裂面假设下得到的破裂面角与被动土压力系数，推导了有限土体的被动土压力解，该公式也可退化为半无限土体的被动土压力解. 与模型试验相比，所提理论解与试验值吻合较好，证明了解析解的合理性. 参数分析表明：考虑层间剪应力下不影响被动土压力的合力，但会使其合力作用点升高；被动土压力随土体宽高比减小呈现先变化不大后急剧增加的趋势；被动土压力合力随内摩擦角增加呈单增趋势，而合力作用点则随之降低.

Analysis of Passive Earth Pressure for Limited Soils Considering Action of Shear Stress

Taking the sand soil in the limited range behind the retaining wall as the object, the relationship between the retaining wall displacement and the internal and external friction angles is established. Assuming that the earth behind the wall is arc-shaped and considering the shear stress between the soil layers, the angle of fracture surface and passive earth pressure coefficient under the hypothesis of multichannel slip surfaces are adopted, and then the theoretical formula of passive earth pressure with limited soil is derived. It can also be degenerated into the solution of passive earth pressure with semi-infinite soil. Compared with the model test, the proposed theoretical solution is in good consistency with the experimental values, which verifies the rationality of the analytical solutions. Parameter analysis shows that: considering the inter-layer shear stress, the total value of passive earth pressure is not influenced, while the position of action point is higher. The passive earth pressure changes little at first and then increases significantly with the decrease of the soil aspect ratio. With the increase of the internal friction angle, the resultant of passive earth pressure increases while the position of action point is lower.