Numerical assessment of sinkhole-induced damage to buildings

In this paper, an advanced chemo-hydro-mechanical (CHM)-coupled numerical model for soft rocks is used to predict the temporal evolution of settlement damage to buildings on cavities subject to weathering. By using surface differential settlements obtained by CHM coupled finite element (FE) analyses a building damage index is used (BDI) to assess serviceability conditions. By modelling the reactive transport of chemical species in 3D and using a coupled CHM constitutive and numerical model, it is possible to simulate weathering scenarios and monitor the temporal evolution of surface settlements making the BDI time dependent. This approach is applied to evaluate BDI evolution of a building lying on two anthropic caves in a calcarenite deposit belonging to the Calcarenite di Gravina Formation. The soundness of both constitutive relationship and reactive transport solver are tested by simulating laboratory-scale boundary value experiments. The first is a model footing test on dry and wet calcarenite, while the second is a small-scale pillar that, after the saturation-induced short-term water weakening, fails due to a long-term dissolution weathering process. Finally, both 2D and 3D coupled FE analyses simulating different weathering scenarios and corresponding settlements affecting the buildings above the considered cavities are presented.