考虑土拱效应的挡土墙主动土压力分布

假定挡土墙后土体小主应力拱为圆弧,考虑墙土摩擦角变化对挡土墙后土体滑裂面倾角的影响,分析表明,土拱形状与现有方法有明显差异,并得到了对应不同内摩擦角和墙土摩擦角的侧土压力系数,将其用于水平微分单元法求解平动模式下的挡土墙主动土压力,给出了挡土墙主动土压力强度、土压力合力和合力作用点的理论公式,并与库仑土压力理论、模型试验数据和已有方法进行比较分析。结果表明:挡土墙主动土压力强度与模型试验结果基本吻合;土压力合力与库仑土压力合力相等;但土压力合力作用点和土压力强度计算结果有明显差别。

Distribution of active earth pressure against retaining walls considering arching effects

It was assumed that the trajectory of the minor principal stress behind a retaining wall took the form of a circle. Considering the effect of wall friction angle on the inclination of slip plane behind the wall, it was shown that the shapes of the minor principal stress arch and the average vertical earth pressures were different from those of the existing methods. The coefficient of earth pressure versus the angle of internal friction and the angle of wall friction was obtained. Using the coefficient in the method of horizontal differential element to compute active earth pressures on retaining wall, the theoretical formulae of the unit earth pressures, the resultant force and the points of application of the resultant force were derived. The proposed method was compared with the existing methods and some experimental data.