Unsaturated soil desiccation cracking is a coupled hydro-mechanical problem.It seriously weakens the hydraulic and mechanical characteristics of soil,causing various natural disasters potentially.For the unsat-urated soil,the mechanism of moisture diffusion and deformation is more complicated compared with saturated soil,attracting wide attention.Thus,a coupled hydro-mechanical bond-based peridynamic(BB PD)model was proposed to explore the moisture diffusion and crack propagation in unsaturated soil.Specifically,the moisture diffusion equation for unsaturated soil was recast with the peridynamic differential operator,and an improved micro-modulus was adopted to revise the bond force density in the BB PD.In addition,a hybrid algorithm com-bining the explicit difference scheme for solving the diffusion equation and the implicit scheme for solving the motion equation was adopted,to avoid the incongruity of time steps for two types equations under the same ex-plicit scheme.The validity of the proposed model and algorithm was verified by the examples on the desiccation of an unsaturated soil block and the desiccation cracking of a 3D unsaturated soil plate.The results show the potential of peridynamics in capturing desiccation cracks of unsaturated soil.
维普
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