饱和软粘土地基的损伤模型与震陷计算

基于各向同性弹塑性损伤和Prevost模型的基本理论,把弹塑性等向硬化、运动硬化和各向同性损伤结合起来,推导了循环荷载作用下不排水饱和软粘土弹塑性动力损伤本构模型.考虑到地震作用下土体应力的不规则性,对循环三轴试验获得的粘土残余应变经验计算公式进行了修正,最后将该残余应变引入到损伤演化方程中.通过对地基的震陷计算并与不考虑损伤的模型进行对比,结果表明,该模型能合理地考虑屈服面内应力循环对地基残余塑性应变的贡献.

A damage model for saturated clay foundation and its seismic settlement

Based on the isotropic elastoplastic damage and Prevost model theory, a new dynamic damage model for saturated soft clay under cyclic loading is proposed. Considering the irregularity of stress in soil under earthquake, the empirical formula for evaluating the residual strain of clay obtained by cyclic triaxial test is modified and finally introduced to the damage evolution equation. Calculation of the seismic settlement of foundation and comparison between the model in this paper and the model without considering damage show that the dynamic damage model can preferably calculate residual plastic strain of the foundation produced by cyclic stresses inside the yield surfaces.