Element-free Galerkin method for deforming multiphase porous media

In the proposed element-free Galerkin method for deforming multiphase porous media, displacement of the porous-solid skeleton is modelled by standard Þnite elements while wetting and non-wetting ßuid pore pressures are included as element-free nodes. The matrix formulation is derived from the variational formulation of the multiphase governing equations. The case of a domain with a material or Þeld discontinuity is handled by using Lagrange multipliers. One- and two-dimensional applications are presented for which the results, compared with those obtained by either the closed-form solution standard Þnite-element approach or experimental tests, show the e¦ciency of the proposed technique. The necessity of taking air pore pressure into account for partially saturated soils is discussed: free surface capturing is analysed and the problem of its intersection with outer boundaries (so-called seepage surface) is studied