The numerical solution of the hydro-mechanical-chemical (HMC) fully coupled equations in porous media faces significant challenges due to spurious oscillation in pore pressure and concentration caused by locking and convection dominance. This study proposes a combination of two different discretization schemes: (1) the Galerkin discretization on the primal mesh for the soil skeleton deformation, and (2) the finite volume method (FVM) on the dual mesh for solute transport and fluid flow, named G-FVM, where the approximations of skeleton displacement , pore pressure , and concentration are established by NMM, to reflect compressible and incompressible deformation. Typical examples of chemo-osmotic and chemo-mechanical consolidation are simulated to verify the accuracy of the G-FVM. Through the numerical tests of 1D and 2D chemo-mechanical consolidation problems, it is evident that when convection-dominated solute transport is associated with Biot’s consolidation law, two different numerical oscillations are observed in both pore pressure and concentration if only the Galerkin method is applied. Nevertheless, the G-FVM did not produce oscillations in either pore pressure or concentration and is free of locking and convection dominance, accurately predicting the response of low-permeability porous media.

Keywords: Hydro-mechanical-chemical coupling; Numerical manifold method; Galerkin’s discretization; Finite volume method; porous media

Zheng Hong is a professor at Beijing University of Technology, a Beijing scholar, and a recipient of the National Science Fund for Distinguished Young Scholars. The main research direction is computational geotechnical mechanics. Some of the achievements have been fully incorporated into the undergraduate and master's textbooks as well as multiple industry standards, and have been adopted by international large-scale commercial software. Published nearly 100 SCI papers as the first/corresponding author, with near 8500 SCI citations. Continuously selected on the Elsevier High Cited Authors List, he is one of the top 2% scientists in the fields of engineering and applied mathematics released by Stanford University, and also a member of the Global Top Scientists List (in the field of engineering technology). Editorial board member of mainstream domestic and international academic journals such as Journal of Geotechnical Engineering and Computers and Geotechnics.