复杂应力条件下土体各向异性及其建模思路  

Discussion on soil's anisotropy under complicated stress state and the study method

作　　者：张坤勇[1] 殷宗泽[1] 

机构地区：[1]河海大学岩土工程研究所,南京210098

出　　处：《岩土力学》2007年第S1期149-154,共6页Rock and Soil Mechanics

基　　金：河海大学科技创新基金(No.2013-406101)。

摘　　要：由于加荷方式不同,土体在复杂应力状态下在各主应力方向上应力-应变关系表现出显著应力各向异性,在常规三轴试验基础上,采用经典弹塑性理论各向同性土体模型对此不能合理描述。通过真三轴试验,总结应力各向异性柔度矩阵规律,结合试验规律进行相应理论研究,用非线性各向异性弹性矩阵代替弹塑性模型的弹性矩阵,用具有各向异性屈服准则的弹塑性模型描述塑性部分,建立非线性各向异性弹性-塑性模型,可以改善柔度矩阵矩阵形态,反映复杂应力状态下土体应力各向异性特征。Stress-induced anisotropy is one of very important characters of soil and also key difference from metal material,which exist in many geotechnical projects. The traditional soil's constitutive models,which are developed with the isotropic assumption,cannot describe such stress strain relationship. Based on a series of true-triaxial tests under complex stress states,basic anisotropic deformation mechanism and mechanical characteristics of soil are discovered,which will supply enough data for the establishment of anisotropy constitutive model. By considering the stress-induced anisotropy under complex stress states,new anisotropic elastic model and anisotropic plastic model may be developed.,which can describe the stress-induced anisotropy.

关 键 词：应力各向异性 土体本构模型 真三轴试验 

分 类 号：TU431[建筑科学—岩土工程]