PORE PRESSURE CYCLING EFFECTS ON SLOPE STABILITY: THE CASE STUDY OF VOLTURINO (ITALY)

The paper presents the preliminary results of a numerical investigation of the effect of cycling pore water pressures on landslide processes. The stability conditions of a natural slope in Volturino (FG, Italy) have been studied using hydro-mechanical finite element simulations implementing an advanced kinematic hardening soil model, which able to account for the degradation of the initial soil structure induced by changes in the water table. The model has been calibrated against available data obtained from laboratory tests on representative soil samples of the Volturino slope. The analyses have been carried out for two permanent hydraulic steady-state conditions. These represent the average pore water pressure regime at the end of winter and summer, which replicate in a simplified way the seasonal fluctuations of the piezometric levels resulting from transient seepage processes generated by the slope-atmosphere interaction. The results demonstrate the ability of the numerical approach to capture the development of deep landslide mechanisms within the slope and the evolution of permanent displacements associated to the continuous accumulation of plastic deformations during the cyclic fluctuation of pore water pressures.