Analysis of the effects of seasonal pore pressure variations on the slope stability through advanced numerical modelling

The paper presents novel results from the advanced numerical modelling of the effect of cycling pore water pressures on landslide processes. It combines the sta-bility analysis of a prototype natural slope through a hydro-mechanical non-linear fi-nite element approach with the calibration of a kinematic hardening model against rep-resentative laboratory data, to draw conclusions of significance to both researchers and designers. The analyses have been carried out for two permanent hydraulic steady-state conditions representing the average pore water pressure regime at the end of the winter and summer season, thus replicating in a simplified way the seasonal fluctua-tions of the piezometric levels resulting from transient seepage processes generated by the slope-atmosphere interaction. The work shows the ability of the constitutive law, seldom used in these kind of analyses, to predict a progressive accumulation of plastic deformations during the cyclic fluctuation of pore water pressures associated to cli-mate. More importantly, the output of the advanced modelling are useful to support the phenomenological interpretation of the landslide processes associated to natural haz-ards and to provide guidance for the sustainable management of marginally stable slopes affected by a constant evolution of permanent displacements.