Modelling of wetting tests for a natural pyroclastic soil

Abstract

The so-called wetting-induced collapse is one of the most common problems associated with unsaturated soils. This paper applies the Modified Pastor-Zienkiewicz model (MPZ) to analyse the wetting behaviour of undisturbed specimens of an unsaturated air-fall volcanic (pyroclastic) soil originated from the explosive activity of the Somma-Vesuvius volcano (Southern Italy). Both standard oedometric tests, suction-controlled oedometeric tests and suction-controlled isotropic tests are considered. The results of the constitutive modelling show a satisfactory capability of the MPZ to simulate the variations of soil void ratio upon wetting, with negligible differences among the measured and the computed values.