Unsaturated-saturated Seepage Analysis Of Soil Slope Considering The Escape Of Porous Gas

Based on the consideration of the escape of gas pore unsaturated saturated seepage field, in saturated soil Drucker-Prager model introduced suction component and applied shear unified strength formula, unsaturated soil slope seepage- mechanical coupling numerical analysis and study of pore gas evolution of unsaturated saturated seepage effects.By considering the slope rainfall infiltration of the boundary conditions of the conversion and use model Fredlund-Xing negative pore water pressure and unsaturated permeability coefficient and the unsaturated soil permeability coefficient can be updated at each time step, thus in FLAC3 D finite difference divided into software in the unsaturated saturated seepage analysis. Based on the conditions of the escape of the pore gas, the formula of the escape range of the pore gas is derived, and the unsaturated saturated seepage field with the escape of the pore gas is established.Based on the non associated flow rule, the equivalent cohesive force is introduced into the Drucker-Prager model, and the shear strength of unsaturated soil is derived by uniform formula. And in consideration of the unsaturated soil seepage process in soil bulk density changes, using the finite element software existing unsaturated soil slope stability analysis and study of pore gas escape for the slope unsaturated saturated seepage and stability of the impact. The variation law of pore water pressure, permeability coefficient, slip surface and safety factor of slope are summarized.