On an Elasto-Plastic Stress-Strain-Time Relationship of Cohesive Soils

The deformation of the cohesive soils is characterized by its large influence of stress histories and its time-dependancy. So, to solve the soil engineering problems of the cohesive soils, constitutive equation (stress-strain-time relationship in terms of tensor) must be established. Previously, an elasto-plastic incremental stress-strain relationship of the cohesive soils has been obtained which is derived on an assumption that the cohesive soils are strain-hardening materials not only for shear but for compression. In this paper, an constitutive equation as macro-rheology is proposed which is obtained by considering time-dependancy to the previous relationship. And after the determination of the demanded soil parameters on undisterved saturated clay, a triaxial comp. test experienced stress histories in advance is carried out. And the results of the comparrison of both observed and calculated values, it has been acertained that the proposed equation estimate reasonably the elasto-plastic stress-strain-time behaviour of the cohesive soils