Introducing the fluid-mechanical interaction model based on continuous porous media theory and mixture theory

applying FISH language to program

the initial seepage field setting function

the saturated-unsaturated seepage analysis module

the special stress-correction module and shear strength correction module are established. Saturated-unsaturated seepage analysis is conducted with FLAC3 D. The effective stress and shear strength of soil zone in the semi-saturated region is modified based on the saturated-unsaturated seepage field and the principle of fluid-mechanical coupling for completely saturated element and extended to unsaturated soil element in FLAC3 D. Based on these analysis modules from secondary development

the water drainage experiment from a sand column conducted by Liakopoulos is numerically simulated to verify the correctness of the model and program. The effect of rainfall infiltration on the seepage field

displacement field and stability evolution of soil slope reveals the mechanism of rainfall-induced failure of slope.