Analysis of cohesive cracking in saturated porous media using an extrinsically enriched EFG method

The subject of this study is to investigate propagation of cohesive cracks under various mixed mode conditions in saturated porous media. The mesh-free EFG algorithm, which uses the MLS shape functions for approximating both displacement and pressure fields, is used. An enrichment approach similar to XFEM, which exploits the Heaviside step function as the enrichment function for representing the crack surfaces is adopted. Basic formulations are developed for saturated fully coupled porous media, and a series of benchmark problems are assessed through the enriched EFG formulations. Both cases of uncoupled and fully coupled formulations for the solid displacements and the water pressure are presented. For the fully coupled case, the effect of mass exchange through the fracture and the surrounding undamaged media is examined. The results predicted by the present numerical framework are in good agreement with existing solutions in the literature.