冻土与结构接触面循环剪切损伤模型

A damage model for frozen soil-structure interface under cyclic shearing

抗剪强度和压缩体应变是冻土与结构接触面的力学特性指标中最重要的两个参数,对冻土与结构接触面的力学分析至关重要。采用自行研制的大型多功能冻土-结构接触面循环直剪系统,开展了冻土与结构接触面力学性能及变形规律的试验研究,采用损伤力学理论,基于等应变分布假设、零弹性域假设、弹性应变无耦合假设,选择不可逆性体应变与最大不可逆性体应变的比值作为损伤因子,建立了用于描述冻土与结构接触面剪切行为的抗剪强度与压缩体应变损伤模型。通过相关试验对建立的损伤模型进行验证,结果表明,所建模型是准确、合理的。

The shear strength and compressive volumetric strain are two key parameters which control the mechanical behaviors of the frozen soil-structure interface. A large-scale multifunctional direct shear apparatus is first designed and manufactured, and then used to determine the mechanical properties of the frozen soil-structure interface. Based on the experimental results, the principles of continuum damage mechanics are employed to develop a shear strength and compression damage model, which can be used to describe the mechanical behavior of frozen soil-structure interface. In the proposed model, the conditions of uniform strain, vanishing elastic zone and uncoupled elastic strain are assumed, and the ratio of irreversible volumetric strain to the maximum irreversible strain is used as a damage factor. Comparison of simulated and experimental results shows that the proposed model yields good results.