Efficient block preconditioners for the numerical modelling of geological faults

The Finite Element modelling of geological faults by penalty contact elements may give rise to illconditioned stiffness matrices with the convergence of iterative solvers accelerated, or even allowed for, by the development and implementation of appropriate preconditioners. The present communication investigates the performance of three different block preconditioners in a realistic geomechanical problem of large size. The results show that the proposed approach may represent an easy to implement, robust and effective alternative to well-established preconditioners such as the incomplete Cholesky factorization with partial controlled fill-in.