Stabilization procedures in coupled poromechanics: A critical assessment

Numerical solutions for problems in coupled poromechanics suffer from spurious pressure oscillations when small time increments are used. We present an overview of stabilization methods that in our view are promising. In particular we investigate the fluid pressure laplacian stabilization (FPL) and a method derived by using finite increment calculus (FIC). On a simple 1D test problem we investigate stability of the two methods. While the analysis reveals that FIC stabilizes the pressure for all time step sizes, it leads to a definition of the stabilization parameter in the case of the FPL stabilization. Numerical tests in one and two dimensions on 4-noded bilinear and linear triangular elements confirm the effectiveness of both the FPL and the FIC stabilization schemes. A bearing capacity analysis demonstrates that the FPL-method also works for non-linear material behavior.