考虑刚度非线性软化的修正硬化土模型

基于硬化土模型(HS模型)只能描述土体应变硬化行为和刚度线性软化现象，提出了考虑刚度非线性软化的修正硬化土模型。修正模型采用与分段幂函数关系描述初始骨干曲线，并考虑了初始静偏应力和加载速率对应力-应变关系的影响。修正HS模型能较好地描述不同初始静偏应力和加载速率下土体的应变硬化、应变软化和刚度非线性软化等特征。最后，基于原状杭州软粘土的三轴试验，验证了修正模型的合理性。

A MODIFIED HARDENING SOIL MODEL CONSIDERING NONLINEAR DEGRADATION OF STIFFNESS

The Hardening Soil (HS) model can only describe the behavior of strain hardening and the linear degradation of stiffness of the soil. A modified HS model was developed to consider the nonlinear degradation of stiffness. The initial backbone curve in the modified HS model was described by using segmented power function of and , and the influences of the initial static deviator stress and loading rate are also considered. The modified HS model can describe the nonlinear degradation of stiffness, the behavior of strain softening and strain hardening under different initial static deviator stress and loading rate. The modified HS model is verified against the traxial testing results for Hangzhou clay.