ABSTRACT
ABSTRACT: The collapse of underground openings, caused by the degradation of the mechanical properties of mined rocks, can result in large settlements of the soil at the surface. This can be in turn a source of relevant damages to existing buildings. The paper aims at investigating the phenomenon by means of continuous (FEM) and discontinuous (DEM) models. Finite Element analyses are based upon a suitably conceived constitutive model of the mechanical behaviour of soft rocks exposed to weathering. The behaviour of such rocks is described by an elastoplastic strainhardening model, in which the hardening law depends on plastic strains experienced and on an appropriately defined degradation parameter of chemical origin. Distinct Element analyses are performed with the code PFC3D. The parameters of the constitutive model and those of the DEM model are calibrated on the basis of selected test results performed on artificial soft-rock. Eventually, the subsidence induced by degradation of pillars in abandoned mines is studied, with both models.
1 INTRODUCTION
