THERMO-MECHANICAL 3D MODELING OF DEEP GEOLOGICAL STRUCTURES USED FOR WASTE DISPOSAL

摘要

Deep geological structures like salt structures have been investigated for their suitability as a repository for radioactive wastes. To prove the long-term safety of the geological barrier, a safety analysis has to be carried out including finite-element calculations to predict the thermomechanical behavior under repository conditions. To this aim, numerical modeling must incorporate large geological structures on a far-field or regional scale, complex geological situations including folded layers and different geological units, a complex geometry of the repositories, extremely long analysis periods up to hundred thousands of years, and a complex material behavior including creep and dilatancy of the host rock. To analyze these problems, BGR has been developing the JIFE finite-element code to consider especially large 3D structures, coupled thermal-hydraulic-mechanical processes, and different constitutive material models to describe the strongly non-linear time-dependent behavior of rock salt.