Application of Ubiquituous-Joint Model for Modelling Fractures in Crystalline Rock Formations: Preliminary Studies

Rock salt, claystone and crystalline rock are considered as potential host rocks for the disposal of high-level radioactive waste in Germany. Rock types, properties, and composition determine how these potential geologic barriers contribute to the containment, isolation, and retardation of the radioactive waste. Crystalline rocks are anisotropic and heterogeneous due to the presence of discontinuities. Therefore, the consideration of discontinuities in numerical models is crucial with regard to the performance assessment of radioactive waste repository systems. The project aims at developing a modelling strategy that enables effective modelling of fractures in crystalline rock. The continuum modelling approach using a Ubiqitous-Joint model is adopted to model the rock fractures. Its applicabilty for large-scale anyalses of anisotropic rock masses is being investigated by developing the numerical models based on predefined structural-geologic information. The influence of fracture orientations on the modelling of the rock masses will be studied, and their impact on performance assessments for the safe disposal of high-level radioactive waste in crystalline rock will be assessed.