Abstract: Based on the modified Cambridge model, an elasto-plastic model was established to describe the physical-mechanical behavior of unsaturated granite residual soils by adjusting the yield surface, and the basic incremental format of the modified Cambridge model was derived. The interface program of ABAQUS was developed to realize the stress and deformation analysis of unsaturated granite residual soil. Compared the simulation results with test data of unsaturated granite residual soils measured by GDS (global digital system) triaxial apparatus. The results show that the simulation results are consistent with the experimental results.

Key words: granite residual soil, unsaturated soil, physical-mechanical property, modified Cambridge model