Simulation of triaxial compression tests for unsaturated soils by using an elastoplastic model

We have carried out the series of triaxial tests for an artificial soil (DL clay) which inherits collapse phenomenon. We have also proposed an analysis method of collapse behavior which consisted of consolidation analysis method and an elastoplastic model in which two suction effects were taken into account as the functions of effective suctions *. The isotropic compression and triaxial compression tests under constant suction values were simulated using the method. According to the simulation results of isotropic compression tests, the method could estimate the amount of collapse and also well express the characteristics that yield stress becomes larger with the increase in suction. From the simulation results of triaxial compression tests, the method could well express the experimental characteristics that the shear stiffness increased with the increase in suction.