An elastic-viscous-plastic model for overconsolidated clays  

作　　者：YAO YangPing KONG LingMing HU Jing 

机构地区：[1]School of Transportation Science and Engineering,Beihang University

出　　处：《Science China(Technological Sciences)》2013年第2期441-457,共17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. 51179003,11072016,11272031);the Specialized Research Fund for the Doctoral Program of Higher Education (Grant No.20091102110030)

摘　　要：The influences of time on clays are discussed first,and the concept of the instant normal compression line is proposed by analyzing the existing theories and experimental results.Based on the creep law,the relationship between the aging time and the overconsolidation parameter is built.With the reloading equation of the UH model(unified hardening model for overconsolidated clays) used to calculate the instant compression deformation,a one-dimensional stress-strain-time relationship is proposed.Furthermore,the evolution of this relationship is analyzed,and the characteristic rate that is a function of the overconsolidation parameter is defined.Then a three-dimensional elastic-viscous-plastic constitutive model is suggested by incorporating equivalent time into the current yield function of the UH model.The new model can describe not only creep,rate effect and other viscous phenomena,but also shear dilatancy,strain softening and other behaviors of overconsolidated clays.Besides,compared with the modified Cam-clay model it requires only one additional parameter(the coefficient of secondary compression) to consider the creep law.Finally,because the proposed model can be changed into the UH model under instantaneous loading,the elastic-plastic and elastic-viscous-plastic frameworks are unified.

关 键 词：CREEP VISCOPLASTICITY STRESS-STRAIN overconsolidation THREE-DIMENSIONAL 

分 类 号：TU43[建筑科学—岩土工程]