非线性破坏准则对主动土压力的影响

Influences of nonlinear fallure criterion on active earth pressure

本文采用非线性破坏准则分析和确定了刚性挡土墙主动土压力大小和滑动面位置。首先应用"切线法"引入了变量ct和φt,然后运用迭代法计算得出对应于不同潜在滑动面上的ct和φt值,再运用广义库仑土压力理论求解主动土压力大小。其中对应于最大主动土压力的滑动面即为最危险滑动面,此时的所求即为主动土压力。通过与采用线性Mohr-Coulomb破坏准则下的研究结果比较得出,采用非线性破坏准则确定刚性挡土墙主动土压力更加符合实际工程,结果更加准确,而采用线性Mohr-Coulomb破坏准则计算的主动土压力结果偏小,在实际工程设计中偏于不安全。

The nonlinear failure criterion is employed to determine the active earth pressure and the position of slip surface in this paper. Firstly, the variables Ct and Фt are created by tangents method, then Ct, and Фt, corresponding to different potential slip surfaces are calculated by iteration method and the active earth pressure is obtained by using generalized Coulomb soil pressure theory. The slip surface, which has the maximum active earth pressure, should be the most dangerous slip surface, and the maximum active earth pressure is also what we desired. After comparing with the research results by Mobr-Coulomb linear failure criterion, it is concluded that the active earth pressures behind the rigid retaining wails, which are calculated by the nonlinear failure criterion, will be more practical and accurate, while adopting the Mohr-Coulomb linear failure criterion will provide a lower active earth pressure values, therefore, will cause insecurity in real project.