路基工程失稳—强度折减有限元反分析探讨

Discussion of FEM Back Analysis from Instability and Strength Degradation in Subgrade Engineering

针对路基工程变形与失稳问题，本文提出了基于非均质弹性损伤模型的有限元失稳—强度折减反分析法，认为材料参数服从统计分布，并以此来描述材料的非均匀性。对同一计算模型，分别采用均质的弹塑性本构模型和非均质的弹性损伤本构模型，对比两种情况下的计算结果，分析了材料非均匀性对稳定性的影响。对处于岩溶地区路基工程实例进行分析，通过强度折减，再现了路基工程的破裂与失稳过程，并得出了失稳时的强度参数，对路基工程具有重要的指导意义。

According to the problem of failure and instability in subgrade engineering, on the basis of inhomogeneous elastic damage model,in this paper FEM back- analysis from instabillty-strength degradation is propose, which suggests that the material parameter obey statistical distribution and it is used to describe the inhomogeneity of material. To the same calculation model,adopt homogeneous elastic-plastic model and inhomogeneous elastic damage model separately,the results of calculation under two kinds of situations are compared, the impact of material inhomogeity on stability is analyzed. Analyzing the subgrade projects in the karst area through strength degradation, it reproduces the breaking and steadiness losing course in the subgrade engineering, the intensity parameter while losing steadilness, and has certain directive significance to the subgrade engineering.