A 3D elastic-plastic-viscous constitutive model for soils considering the stress path dependency  

作　　者：LU DeChun MIAO JinBo DU XiuLi TIAN Yu YAO YangPing 

机构地区：[1]Key Laboratory of Urban Security and Disaster Engineering of Ministry of Education,Beijing University of Technology,Beijing 100124,China [2]School of Transportation Science and Engineering,Beihang University,Beijing 100191,China

出　　处：《Science China(Technological Sciences)》2020年第5期791-808,共18页中国科学（技术科学英文版）

基　　金：supported by the National Natural Science Foundation of China(Grant Nos.U1839201,51778026,51421005&51538001).

摘　　要：In order to consider the stress path dependency of soils,this paper decomposes any arbitrary stress path into several infinitesimal stress paths.Then the infinitesimal stress path is further transformed into the superposition of two parts,i.e..a constant stress ratio part and a constant mean stress part,which arc sufficiently close to the real stress path.T he plastic strain increments under the transformed paths arc determined separately,and then the plastic strain under any path is obtained.Based on the instantaneous loading line of normally consolidated soil,a reference state line is proposed to determine the overconsolidation ratio and creep time of soil.The overconsolidation ratio is introduced into the viscous How rule to obtain the viscous strain increment.The strcss-strain-timc relationship for triaxial compression condition is extended to 3D stress condition by the transformed stress method.The proposed model adopts only seven material parameters and each of them has a clear physical meaning.Comparisons with test results demonstrate that the model can not only reasonably predict the plastic strain under typical stress paths of excavation,but adequately capture the time-dependent behaviours of soils,including creep,stress relaxation and strain rate effect.

关 键 词：SOILS clastic-plastic-viscous constitutive model stress path dependency reference stale line CREEP stress relaxation 

分 类 号：TU43[建筑科学—岩土工程]