关于土体各向异性弹塑性模型的讨论

用剑桥模型和关口太田模型对偏载作用下的地基变形进行了有限元数值模拟,并结合真三轴试验成果比较分析了这2种模型柔度矩阵的特点.结果表明,这2种模型均不能合理地反映复杂应力状态下的土体应力各向异性.建议通过复杂应力条件下不同应力路径的真三轴试验,建立合理的各向异性屈服准则,进而建立各向异性非线性弹塑性模型.

Discussion on anisotropic elastic-plastic constitutive model for soil mass

Numerical simulation of foundation deformation under asymmetrical loading with the finite element method was performed by use of the Cam-Clay model and the Ohta-Sekiguchi model.The comparison of the matrixes of flexibility of the two models based on the results from the true triaxial tests shows that Ohta-Sekiguchi model can reflect initial K_0 consolidation to some extent by adjusting yield locus,but neither of the two models can reflect the stress-induced anisotropy of soil mass in the complicated stress state.It is suggested that the true triaxial test under different stress paths should be performed to derive reasonable anisotropic yield criterion and further to develop nonlinear anisotropic elastic-plastic constitutive model.