ABSTRACT
Rock salt represents a key host rock candidate for deep geological storage of nuclear waste and has been the subject of extensive investigation. To make accurate predictions about the stability and integrity of a repository, a simulation model requires an appropriate representation of the creep behavior of rock salt. On the associated time scales, glaciation periods in particular induce profound changes in mechanical (M), hydraulic (H) and thermal (T) boundary conditions and therefore require further investigation. As part of the AREHS project, we analyse the influence of the coupling of THM physical processes and perform simulations with different coupling schemes (M, TM, HM, THM) for a relevant scenario. Furthermore, we examine the difference in the numerical results between a basic power law creep model and a composite power law that includes both dislocation and pressure-solution creep. The models produce significantly different mechanical responses under glacial loading, highlighting the importance of the pressure solution creep effects at low deviatoric stresses. Due to the simplicity of the model, including hydraulic and thermal coupling had minimal influence in comparison.
