浸水条件下有限土体土压力试验研究与数值分析

采用自主设计自动控制模型箱,开展了墙后有限宽度浸水无粘性土体在绕墙底转动、平动及绕墙顶转动3种位移模式下的主动土压力试验,并通过ABAQUS进行数值模拟,分析研究了墙后不同宽度土体的破坏形式及其土压力分布规律。研究结果表明,3种位移模式下,有限土体宽度较窄时破裂面被固定挡墙截断,随着填土宽度的增加破裂面开始延伸至填土表面,并最终稳定于库伦破裂面内侧。3种位移模式下的有限土体土压力分布均明显小于水土分算值,且随填土宽度的增加而逐渐接近水土分算理论值;绕墙底转动时土压力分布接近三角形分布,平动时土压力随土体宽度增加渐呈“勺型”分布,而绕墙顶转动时则呈“S”型分布规律。

Experimental Research and Numerical Analysis on Active Soil Pressure of Limited Soil under Water Immersion

An experiment, by using the self-made automatic control model box, was conducted to study the active earth pressure of saturated cohesionless soil with limited width behind retaining wall in three displacement modes: rotation around bottom, translational motion and rotation around top. Through ABAQUS numerical simulation, the damage form of the soil and the distribution rules of earth pressure were analyzed and studied. The research results show that under these three displacement modes, the fracture surface is cut off by the fixed retaining wall when the width of finite soil is narrow, and with the increase of the filling width, the rupture surface extends to the surface of the fill and eventually stabilizes in the inside of Coulomb failure surface. The distribution of limited-width soil pressure under these three displacement modes is obviously less than that of the theoretical value obtained by method of estimating water and earth pressures separately. What's more, the distribution of soil pressure intensity increases with the increase of the fill width and finally approaches the theoretical value of estimating water and earth pressures separately. The distribution of earth pressure approaches the triangle distribution when rotating at the bottom; presents a “spoon” distribution with the increase of soil width when the motion of retaining wall is translational; and shows an “S” distribution pattern while it is rotating around the top.