两种位移模式下挡墙主动土压力的离散元模拟

DEM Analyses of Active Earth Pressure against Retaining Wall with Two Displacement Models

挡土墙位移模式是影响挡土墙土压力问题的关键因素之一,位移模式不同,土压力大小、分布也不同。文章用离散元软件PFC2D模拟了不同位移模式下墙后填土为砂土时挡墙土压力问题,分析了总土压力随位移变化情况,土压力分布情况及土体滑裂面形状、顶宽等问题。研究结果表明:土压力分布,大小与挡土墙位移模式有关,挡土墙背离土体平移即T模式下土压力分布呈线性、而绕墙底转动即RB模式下土压力基本呈线性分布,挡土墙位移较小时,土体便能达到主动极限状态;T模式下滑裂面为通过墙底的平面,而RB模式下滑裂面为未通过墙底的平面,T模式下滑裂面顶宽大于RB模式下相应值。

This paper studies the active earth pressure with two different displacement models against the retaining wall using PFC2D. The displacement model is one of the important factors to the earth pressure. The distribution of earth pressure against retaining wall and the total earth pressure at different displacement of the retaining wall are studied. The sliding surface of the soil behind the wall and the width of the sliding surface are studied too. The results show that the distribution of the earth pressure and the total earth pressure is different with different displacement models of the retaining wail. The distributions of the earth pressure of T model are nonlinear, and the total earth pressure with RB is larger than that with T. Under a little displacements of the retaining wall the soil behind the wall can reach the ultimate condition. The sliding surface with T is nearly a parabohc, while nearly linear with RB. And the width of the sliding surface with T is larger than that with RB.