旋转位移假设下,将挡土墙和填土看成一个系统,建立挡土墙在地震作用下的旋转破坏模式,应用极限分析上限法推导了系统外力功率和耗散功率,得到了水平屈服加速度系数的理论计算公式,并采用MATLAB语言进行数值求解,获得了破裂角和水平屈服加速度系数的数值解。计算公式考虑了填土与墙体接触面上的黏聚力、墙和填土的摩擦角、竖向地震加速度系数、填土黏聚力、填土内摩擦角等对水平屈服加速度系数的影响。研究结果表明:填土与墙体接触面上的黏聚力、墙和填土的摩擦角和竖向地震作用对水平屈服加速度系数的影响显著,在实际工程设计中需合理取值以达到安全经济的目的。
The retaining wall and the backfill soil are taken as a whole system. For a rotational failure mechanism assumed, the paper studies the external work rate and internal energy dissipation rate by combining the slice method and limit analysis upper bound method. Based on virtual power principle, the formulae are obtained to calculate the horizontal yield acceleration coeff~cient, numerical solutions of the inclination of the failure surface and the horizontal yield acceleration coefficient are obtained by MATLAB Case studies are given to illustrate the method, the influential factors such as cohesion and internal frictional angle between filling and wall, vertical seismic coefficient, cohesion and internal friction angle of filling are considered and analyzed. The results show that cohesion and internal friction angle between filling and wall, and vertical seismic effect have a significant influence on the horizontal yield coefficient, the design of retaining wall ought to pay enough attention to this aspect in order to achieve the purpose of economy and security.