Numerical modeling of the thermomechanical behavior of a large-scale underground experiment

The numerical simulation of the thermal and thermomechanical response of the large-scale in situ experiment “thermal simulation of drift emplacement”, which was carried out in the Asse salt mine in Germany, is presented. The analyses concern the modeling of the temperature fields, thermally induced drift closure followed by the consolidation of backfill material and the distribution of the stresses. Finite element codes specially developed for the repository structures as well as a general-purpose code have been used. The primary objective of the investigations is to evaluate the capability of these codes to simulate the thermomechanical behavior of rock salt and backfill material under representative conditions of a waste repository by comparing of calculated results with in situ measurements. An overall good agreement between modeling and in situ measured results indicates that most thermomechanical effects are fairy well represented by the numerical models.