Retracted: Subloading Surface Plasticity Model Algorithm for 3D Subsidence Analyses above Gas Reservoirs

Abstract

The coupled hydromechanical state in soils coming from consolidation/subsidence processes and undergoing plasticity phenomena is evaluated by means of the subloading surface model. The most important feature of this theory is the abolition of the distinction between the elastic and plastic domains, as in conventional elastoplastic models. This means that plastic deformations are generated whenever there is a change in stress and a smoother elastoplastic transition is produced. The plasticity algorithm has been implemented in the PLASCON3D FE code, coupling hydromechanical fields within a saturated porous medium (locally partially saturated at the reservoir level owing to the possible presence of a gas phase) subjected to external loads and water/gas withdrawals from deep layers (aquifers/reservoirs). The three-dimensional (3D) model is first calibrated and validated against examples taken from the literature and then subsidence analyses at regional scales owing to gas extractions are developed to predict the evolution of settlements and the pore pressure in soils for long-term scenarios.