Numerical simulation of wet deposited Phosphogypsum embankment resting on dry deposited one

Abstract

This paper studied the numerical simulation of wet deposited Phosphogypsum (PG) embankment on an existing dry one by the Plaxis and Midas GTS geotechnical codes. Following the sequences of PG embankment construction, a plane strain model permitted the simulation of the conventional wet deposit process of PG. Mohr-Coulomb constitutive model with appropriate parameters describe the behavior of Tunisian Phosphogypsum residue. The implementation of suitable numerical procedure led to predict the evolution of settlements and horizontal displacements during the construction of PG embankment. Comparison between predictions by Plaxis and Midas codes overall showed similar trends, in particular, the occurrence of maximum settlements after the construction of peripheral basins located at the crest of PG embankment, while the lowest settlement occurs under the central basin located at the axis of whole PG embankment. For each stage of PG embankment construction, the predictions showed constant settlement. The adopted stage construction scheme highlighted alternated settlement and heave movements, from which observed in situ cracks within the PG deposited PG were justified.