ABSTRACT

The seismic passive earth pressure is typically calculated by a pseudo static analysis by the PGA on the ground surface which is often assumed to be constant within the soil mass. This may result in an underestimation of the limit load. On the other hand, variations of the acceleration field over time and space render the interpretation of the seismic limit load either very difficult, if a complete elasto-plastic solution is sought at each time step, or argumentative. A rather new procedure is presented in this study which considers the variable seismic acceleration field behind a rigid retaining wall during an earthquake and applied to a series of acceleration time histories. The method of stress characteristics is implemented to estimate the limit load at each time step. This method seems to be more convenient with a clear interpretation of the actual limit load. Results indicated that the conventional pseudo static analyses provide an over-conservative estimate or an underestimation of the passive earth pressure.

摘要

地震被动土压力通常通过 PGA 对地表的伪静态分析进行计算，通常假定地表在土体中是恒定的。这可能会导致低估限制负载。另一方面，加速度场随时间和空间的变化使得地震极限载荷的解释要么非常困难，要么在每个时间步寻求完整的弹塑性解决方案，要么有争议。本研究提出了一个相当新的程序，它考虑了地震期间刚性挡土墙后面的可变地震加速度场，并将其应用于一系列加速度时间历程。实施应力特性的方法来估计每个时间步长的极限载荷。这种方法似乎更方便，可以清楚地解释实际的极限负载。结果表明，传统的拟静态分析提供了对被动土压力的过度保守估计或低估。