用接触面弹塑性损伤模型分析群桩基础

探讨了接触面弹塑性损伤模型在群桩基础响应分析中的适用性。建立了用于有限元分析的弹塑性损伤接触面单元。采用多种接触面模型及多组模型参数对单调和循环荷载作用下的群桩基础与地基相互作用进行了三维有限元分析。结果表明:弹塑性损伤单元能够合理地描述包括体应变及其与剪应变的耦合特性在内的接触面主要静动力学特性;接触面的力学特性对桩土相互作用分析有重要影响;Clough-Duncan模型和理想弹塑性模型不能反映接触面的体应变及其与剪应变耦合特性,算得的桩的响应与弹塑性损伤接触面单元差别较大。因此,使用弹塑性损伤接触面单元进行土体与结构物相互作用分析较为合理。

Soil-structure interface modeling of pile-soil interaction with an elasto-plasticity damage model

Soil-structure interface models are used to analyze the stress coupling between piles and the surrounding soil which greatly affects the soil-pile interaction. An interface element based on the elasto-plasticity damage model for Interfaces was implemented into FEM analysis software to more accurately model soil-pile interaction. 3-D static and cyclic interactions between pile groups and soils were then analyzed using various interface models and parameters. The new interface element can effectively simulate the interface behavior including the volumetric stress-strain relationship and the shear stress-strain relationship and their coupling. The Clough-Duncan model and the ideal model do not effectively predict the soil-pile interactions because they cannot reflect the volumetric strain and its coupling with the shear stress-strain relationship. Therefore, the new interface element gives more reasonable predictions for soil-pile interaction analyses.