Numerical simulation of coupled thermal elastic behaviors for hard rock pillar in ?sp? Pillar Stability Experiment, Sweden

The goal of the ?sp? Pillar Stability Experiment performed in ?sp? Hard Rock Laboratory, Sweden is to investigate the mechanical response and progressive failure process of a hard rock pillar during excavation and heating. Numerical simulation of the thermal elastic behaviors for the pillar is one of the three tasks of the DECOVALEX-2011 project. The evolutions of stress, deformation and temperature of the pillar are modeled by using a coupled thermal elasticity model. The research results demonstrate that the thermal elasticity model is suitable for describing the coupled thermal mechanical behaviors of the pillar during excavation and heating. The stress redistribution and temperature evolution processes of the pillar are largely modeled, and the failure process and its propagation are qualitatively analyzed. The major limitations of the thermal elasticity model are its absence of the multiphase flow and progressive failure processes. The model developed and the modeling experiences accumulated in this study may be helpful for the stability and safety assessment of the hard granite host rock in China's Beishan preselected area for high-level radioactive waste disposal.