土结接触面黏聚区域模型及渐进累积破坏分析

Interfacial cohesive zone model and progressive failure of soil-structure interface

首先探讨了土结接触面的含义、接触面相对位移的组成以及接触面的破坏形式,然后提出以黏聚区域模型描述接触面滑动和拉裂破坏变形、邻近非接触面单元描述接触面基本变形的分析思路,建立了基于黏聚区域模型的无厚度接触面单元,有效避免了接触面厚度确定的困难。在强化有限单元法(FEM++)的框架内完成了接触面模型的数值实现后,以直剪试验的模拟揭示了土与结构接触面的渐进累积破坏过程,说明了接触面模型与平均剪应力–剪切位移试验曲线的差异,并对模型本构参数的选取进行了阐述。

The concept of soil-structure interface,the composition of interface-displacement and the failure forms of interface are discussed first,and then an analysis method,in which the slippage of interface and the tension fracture deformations are described by interfacial cohesive zone model and the basic deformations of interface are described by non-interface elements,is proposed.Based on the cohesive zone model（CZM）,the contact elements of zero thickness are established to avoid the difficulty of determining the thickness of interface.After the numerical fulfilling of CZM in the frame of enhanced finite element method（FEM＋＋）,the numerical simulation of direct shear tests is carried out to reveal the progressive failure process of soil-structure interface,and the difference between interface model and experimental shear stress-displacement curve is illustrated.The selection of parameters of CZM is also expounded.