ABSTRACT
Using FLAC3D, the thermo-mechanical effects on the near-field of a KBS-3 type repository were investigated. The temperature development around the repository, due to the heat release from the waste, was first analyzed. The stress change and strains caused by the excavation and the thermal load were thereafter analyzed in eleven time steps. The results show that in the rock pillar between the repository tunnels the temperature reaches a maximum of about 70°C after 55 years of deposition. The extent of yielded rock reaches a maximum at after about 200 years. The extent of overstressed rock depends on the quality of the rock, ground water pressure, and the magnitude and orientation of the in-situ stress field.
