Estimation of active earth pressure based on pseudo-dynamic approach and discretization technique

基于拟动力法和离散化技术的主动土压力估算方法

A method combining the pseudo-dynamic approach and discretization technique is carried out for computing the active earth pressure.Instead of using a presupposed failure mechanism,discretization technique is introduced to generate the potential failure surface,which is applicable to the case that soil strength parameters have spatial variability.For the purpose of analyzing the effect of earthquake,pseudo-dynamic approach is adopted to introduce the seismic forces,which can take into account the dynamic properties of seismic acceleration.A new type of micro-element is used to calculate the rate of work of external forces and the rate of internal energy dissipation.The analytical expression of seismic active earth pressure coefficient is deduced in the light of upper bound theorem and the corresponding upper bound solutions are obtained through numerical optimization.The method is validated by comparing the results of this paper with those reported in literatures.The parametric analysis is finally presented to further expound the effect of diverse parameters on active earth pressure under non-uniform soil.

本文开展了一种拟动力法与离散化技术相结合的主动土压力计算方法的研究。采用离散化技术来生成潜在的破坏面,而不是采用预设的破坏机制,适用于土体强度参数具有空间变异性的情况。为了分析地震作用的影响,引入拟动力法考虑地震加速度动力特性的地震力。采用一种新型的微单元来计算外力的做功速率和内部能量的耗散速率。利用上界定理推导了地震主动土压力系数的解析表达式,并通过数值优化得到了相应的上界解。通过与文献结果的比较,验证了本文方法的有效性。通过参数分析,进一步阐述了不同参数对非均匀土作用下主动土压力的影响。