【摘要】 在城市商业密集区或山区岩石区域修建的挡土墙结构,存在大量靠近已有坚固墙壁或岩壁情形,此时其后填土空间将被限制,而其主动破坏模式与土力学经典模型存在较大差异。引入离散单元法(DEM)方法,对挡墙后无粘性填土在平动模式下的破坏模式进行了分析。结果表明,此时,墙后填土的破裂面无法贯穿整个填土,其为通过墙踵的局部直线型破裂面,即由上矩形部分和下三角形部分组成的梯形截面,破裂面倾角与土体内摩擦角相关。在此基础上,基于极限平衡分析,对梯形滑动面采用薄层单元法建立了主动状态土压力强度的微分表达式,由此导得墙后有限宽度填土的主动土压力计算方法,计算结果与已有试验测试结果吻合良好,表明该方法的合理性。更多还原

【Abstract】 Spaces for backfills are often constrained and narrow when retaining walls must be built close to existing stable walls in urban areas or near rock faces in mountainous areas,and the active destruction mode is quite different from the classical model of soil mechanics. The discrete element method( DEM),using Particle Flow Code( PFC2 D) software,was employed to simulate the behavior of cohesiveless soil with narrow width behind a rigid retaining wall when the wall translation-move away from the soils. The results show that,at this time,the slip surface of the backfill cannot penetrate the entire fill. It is a local linear rupture surface through the wall stump,that is,a trapezoidal cross section consisting of an upper rectangular part and a lower triangular part., friction angle related to the body. Then,based on the limit equilibrium method with the obtained slip surfaces in PFC2 D,a simplified analytical method is presented to obtain a solution for the active earth pressure acting on rigid retaining with narrow backfill width. The calculated values compare reasonably well with those from physical tests in previous literature.更多还原