基于极限平衡理论,考虑土拱效应引起的挡土墙后小主应力偏转,将圆弧形小主应力偏转轴近似为直线形。通过改进水平薄层单元法,提出沿圆弧形小主应力拱割线方向划分微分单元进行主动土压力计算的新方法。并推导出平动刚性挡墙以及墙后土体为无黏性土时的主动土压力强度、合力大小及合力作用高度的理论公式。研究了土体内摩擦角、墙土摩擦角、滑裂面倾角参数对主动土压力强度和合力作用点高度的影响。最后通过实例以及与其他方法的比较验证了该方法的适用性。
Based on the limit equilibrium concept, the trajectory axis of an arc-shaped arch is simplified to be linear considering the trajectory of the minor principal stress induced by arching effect. A new method for the active earth pressure is proposed through the improved horizontal elements, in which the differential fiat elements are divided along the secant direction of the arc-shaped arch trajectory axis of the minor principal stress. Considering a translational rigid retaining wall and cohesionless soil, the theoretical formulas are obtained for the active earth pressure, the resultant earth pressure and the points of applying the resultant earth pressure. In addition, the internal frictional angle of soil, wall-soil fi'ictional angle and angles of sliding plane and horizontal direction, which affect the unit earth pressure, the resultant force of earth pressure and the application point of the resultant force, are investigated. Finally, the proposed formulas produce satisfactory results through comparisons with the experimental observations and other theories.