The coupled hydro-mechanical approach for fluid compressibility problems in porous media

摘要

Numerical modeling for geotechnics use formulations which take into consideration simplifyingrnhypotheses for porous media physical behavior. However, these simplifications neglect effects which couldrncontribute in model’s accuracy. In this paper, a fully coupled hydro-mechanical formulation considering fluidrnand solids compressibility is presented. This formulation was tested for a two-dimensional consolidation case.rnA sensitivity analysis for the fluid compressibility parameter was performed, with comparison of the simulationrnresults to Biot’s analytical solution. Results show that the values of vertical displacements are lower to casesrnwith compressible fluids than to those with incompressible fluids. Instantaneously after load application, fluidrnpressure increases to a maximum value and it dissipates as load is gradually transferred to solid matrix. Forrncompressible fluids, however, there is a delay in fluid pressure dissipation, which makes effective stress lowerrnthan expected. Therewith, stress-strain relations are affected, with low soil strain rate values, justifying verticalrndisplacement decrease.