DOUBLE TIME-SCALE ANALYSIS OF THE CONSOLIDATION OF A 2-STRATA POROELASTIC LAYER WITH HIGH PERMEABILITY CONTRAST

The consolidation of a saturated porous medium submitted to a vertical load is a classical problem, and has been given a complete analytical solution within the framework of linear poroelasticity. For a layer c onstituted by several homogeneous strata, the problem can be dealt wit h by means of analytical as well as numerical methods, provided that t he contrast between the properties of the strata remain moderate. In t his paper, we consider a layer constituted by two strata and discuss t he situation in which the contrast between the properties of the strat a becomes very large and fluid conduction exhibits very different char acteristic times in each stratum. The method used consists in introduc ing a double time scale, and gives an analytical solution, which makes it possible to discuss the influence of the ratio between strata thic knesses on the overall consolidation time of the layer.