Numerical stability analysis of reinforced soil structures using the multiphase model

The stability analysis of soil and rock structures reinforced by groups made of a large number of regularly distributed inclusions, may be appropriately performed by resorting to a multiphase model incorporating a soil-reinforcement failure criterion, as well as the shear and bending resistance of the reinforcements. This contribution develops the numerical implementation of both the lower and upper bound methods of yield design through a preliminary discretization of the structure into finite elements, formulated in the framework of this model and leading to non-linear optimization problems. Two illustrative examples of application are investigated: the stability analysis of a mechanically stabilized earth retaining wall, where it appears that the soil-reinforcement strength condition plays an important role, and the stability of a piled-embankment under seismic loading, where the stabilizing effect of the shear and bending strength characteristics of the reinforcements is highlighted. The comparison with previously obtained results on the same problems points to the good performance and design capabilities of this new computational approach.