摘要
为了刻画岩土材料的各向异性与应力方向性力学行为,从颗粒材料的内应力出发,定义一个新的应力张量——等效应力张量,使之可以综合描述应力的大小、组构的大小以及应力–组构的方向关系。以各向同性本构模型来刻画颗粒接触面的力学性质,以等效应力来描述颗粒间接触应力,提出已有各向同性本构模型进行"各向异性化"改造的"等效应力法",进而建立可以考虑岩土材料各向异性与应力方向性的等效非线性模型,模型仅包含3个参数,且均可以通过严格的理论计算和简单的室内试验加以确定。与砂土定向剪切试验对比表明,等效非线性模型很好地预测了试样的剪切变形与峰值强度的各向异性和应力方向性,为研究岩土材料各向异性和应力方向性提供了新的思路。
In order to describe the anisotropy and the stress direction dependence of geomaterials,a new stress tensor,named the equivalent stress tensor,was defined on the basis of the internal stress of granular materials,so that the stress magnitude,fabric level together with the directional relationship between the stress and fabric can be described.The isotropic constitutive models were used to describe the mechanical properties of particle interfaces and the equivalent stress was used to describe the contact stress between particles.The existing isotropic models can be modified into the anisotropic ones with the equivalent stress method.A new non-linear model was thus established which takes the anisotropy and the stress direction dependence of geomaterials into account.The new model has only three parameters which can be determined by the rigorous theoretical calculations and simple laboratory tests.The nonlinear model predicts accurately the anisotropic shear deformation and peak strength of specimens from the results of shear tests with the principal stress in fixed direction.
出处
《岩石力学与工程学报》
EI
CAS
CSCD
北大核心
2018年第2期506-512,共7页
Chinese Journal of Rock Mechanics and Engineering
基金
国家自然科学基金资助项目(11572165
51778311)~~
关键词
岩土工程
等效应力
应力方向性
各向异性
非线性模型
变形
geotechnical engineering
equivalent stress~ stress directivity
anisotropy
nonlinear model^deformation
