基于内状态变量理论的盐渍土本构模型研究  

Study on Constitutive Model of Saline Soil Based on Internal State Variables Theory

作　　者：陈会官 朱珍德[1,2] 王震 CHEN Huiguan;ZHU Zhende;WANG Zhen(Key Laboratory of Ministry of Education for Geomechanics&Embankment Engineering,Hohai Univ.,Nanjing 210098,China;Jiangsu Research Center for Geotechnical Engineering Technology,Hohai Univ.,Nanjing 210098,China)

机构地区：[1]河海大学岩土力学与堤坝工程教育部重点实验室,南京210098 [2]河海大学江苏省岩土工程技术工程研究中心,南京210098

出　　处：《三峡大学学报（自然科学版）》2020年第4期53-57,共5页Journal of China Three Gorges University：Natural Sciences

基　　金：国家自然科学基金项目(51878249)。

摘　　要：冻结盐渍土的力学行为受盐含量,未冻水含量,围压等多种因素的综合影响.为研究冻结盐渍土的力学行为,基于内状态变量理论,提出一个考虑未冻水含量和围压的双屈服面本构模型.将未冻水含量与围压作为本征变量修正内状态变量理论,从而得到考虑了未冻水含量和围压的Helmholtz自由能.依据得到的Helmholtz自由能,考虑土体的体积变形与剪切变形机制,推导出增量型双屈服面本构模型表达式,并给出了详细的数值计算流程.最后,采用2.5%盐含量冻结盐渍土的常规三轴压缩试验,考虑围压及未冻水含量对土样特性的综合影响对模型进行验证,结果表明模型模拟曲线和试验曲线吻合良好.The mechanical behaviors of frozen saline soil are affected by the combination of salt content,unfrozen water content,confining pressure and many other factors.In order to study the mechanical behaviors of frozen saline soil,a double yield surfaces constitutive model considering the content of unfrozen water and the confining pressure was proposed based on the internal state variables theory.The unfrozen water content and confining pressure were used as the intrinsic variables to correct the internal state variables theory,and the Helmholtz free energy coupled with unfrozen water content and confining pressure can be deduced.According to the coupling Helmholtz free energy,considering the volume deformation and shear deformation mechanism of soil,the expression of incremental double yield surfaces constitutive model was obtained,and the detailed numerical calculation flow was given.Finally,conventional triaxial compression tests of frozen saline soil test with 2.5%salt content were used to verify the model by considering the comprehensive effect of confining pressure and unfrozen water content,and the results showed that the model simulation curves were in good agreement with the test curves.

关 键 词：冻结盐渍土 未冻水含量 围压 双屈服面 内状态变量理论 

分 类 号：TU43[建筑科学—岩土工程]