SFG modified model and particle flow simulation.

Based on the unified yield surface SFG model and combined with the unified hardening parameters, the elastoplastic constitutive model of unsaturated soil is derived. The model is capable of describing the stress–-strain characteristics of over-consolidated unsaturated soils in terms of softening and shear expansion. The model can be degraded to a uniform yield surface SFG model under normal consolidation. The theoretical values of the model were calculated by MAPLE and compared with the experimental results, and the results show that the model can simulate the relevant properties of over-consolidated unsaturated soils better. Using PFC3D to simulate unsaturated triaxial tests, the process of unsaturated soil triaxial experiments was simulated by introducing gas particles and differentiating between the effective stress of the soil and the matric suction, and it was concluded that with higher matric suction, the contact force chains between particles in the specimen become more frequent and it is more difficult to form shear zones. [ABSTRACT FROM AUTHOR]