An improved MLS-based numerical manifold method for saturated-unsaturated seepage in porous media

The moving least squares (MLS) based numerical manifold method (abbreviated as MLS-NMM) inherits the individual merits of MLS and NMM, which not only gets rid of the shackles of meshes but also can unitedly solve both continuity and discontinuity problems. This paper presents an improved MLS-NMM model for saturated-unsaturated seepage in both homogeneous and heterogeneous porous media. In the improved model, the innovative node arrangement scheme and background grid generation strategy are introduced, which can effectively enhance the interpolation accuracy. Five examples are employed to confirm the capability and accuracy of the improved MLS-NMM model. Numerical results manifest that the proposed model can serve as a reliable reference tool for saturated-unsaturated seepage analysis in engineering applications .