Application of UH model to finite element analysis

The over-consolidated unified hardening model (UH model) proposed by Yao et al can describe many characteristics of clays well, including stress-strain relationships, stress dilatancy, strain hardening and softening, and path dependency behavior. Linear Hvorslev envelope has been substituted by a parabola Hvorslev. The parameters in the model are the same as those in the Cam-clay model. By using the UH model, numerical simulation of triaxial tests is performed. The difference of stress-strain curves predicted by using the Cam-clay model and the UH model is analyzed. To the test on rigid bearing plate, three-dimensional finite element analysis of foundation bearing capacity is carried out. The curves p-s are compared using the UH, the Cam-clay and the Mohr-Coulomb models. Stress-strain curves calculated by using the UH model in soil are analyzed. The stresses calculated by using the UH model and Boussinesq elastic theory solution are compared. In addition, numerical analysis of consolidation settlement is performed. The changes of pore pressure and settlement are analyzed and compared. It is shown that the UH model is better than the Cam-clay and Mohr-Coulomb models; and it is easy to be applied to the FEM from the comparisons of various calculation results in this paper.