不同应力路径下结构性土体本构模型研究  

A constitutive model of bonded soilbased on the micro mechanism under different stress path

作　　者：方安明 Fang Anming(Hangzhou Urban Construction and Development Group Co.,Ltd.,Hangzhou Zhejiang 310001,China)

机构地区：[1]杭州市城市建设发展集团有限公司,浙江杭州310001

出　　处：《山西建筑》2023年第21期59-64,共6页Shanxi Architecture

摘　　要：为了研究结构性土在外力作用下结构破损规律及本构模型,在岩土破损力学的框架内,基于细观尺度根据土颗粒在外力作用下的受力模型,建立了胶结土颗粒间变形的几何方程,同时结合结构性土破损的物理力学方程,推导了结构性土在外力作用下破损过程中应变集中系数c和胶结破损率λ的变化规律及本构模型,并讨论了土体模量E和土颗粒间的切向接触刚度ks对模型的影响。研究结果表明:c在荷载作用下随着应变增大呈减小趋势,且主要受ks的影响。λ在受力过程中随着应变的增大而增大,且主要受E的影响;不同的围压下对岩土体进行加载,剪应力呈增大趋势,其性质表现为硬化现象;若对围压进行卸载,剪应力呈先增大,后减小的趋势,岩土体的性质表现为软化现象。In order to research the damage law and constitutive model of nature soil under external force,the thesis within the framework of geotechnical damage mechanics.According to the force model of soil particles under micro-scale.The geometrical equation of the deformation of cemented soil is established.Combined with the physical mechanics equation which can represent the damage of nature soil,deduced the change law of inner parameters of strain concentration coefficient c,the rate of cementation failure of soilλand constitutive model when the nature soil under external force.And the influences of soil modulus E and tangential contact stiffness k s to the c,λand constitutive model was discussed.The results show that c was reduced with the increases of strain and mainly affected by k s,λwas increased with the increases of strain and mainly affected by E.Shear stress was increased during the loading process under different confining pressures and the property of soil performed hardening phenomenon.The shear stress was increased first and then decreased when unloading confining pressure and the property of soil performed soften phenomenon.

关 键 词：岩土破损 胶结土颗粒 应变集中系数 破损率 

分 类 号：TU432[建筑科学—岩土工程]