Joint project: Comparison of constitutive models

This joint project is a collaboration of several project partners with the aim to review and improve tools used for the proof of safety concerning the long-term underground disposal of heat-generating high-level radioactive waste in rock salt formations. This includes constitutive models to describe the thermal-mechanical-hydraulic coupled behaviour of rock salt. The project follows the two BMBF joint projects "Modelling of the mechanical behaviour of rock salt: Comparison of current constitutive models and procedures" (01.04.2004 to 30.11.2006) and "Comparison of current constitutive models and approaches based on 3D model calculations for long-term mechanical behaviour of real underground structures in rock salt "(01.08.2007 to 31.07.2010). In this project, founded by the German Federal Ministry of Economics and Technology (BMWi), the different modelling approaches developed by the project partners to describe the thermo mechanical behaviour of rock salt as well as its healing-ability should be analyzed. Therefore, each project partner performs coupled thermo mechanical 3D benchmark simulations with his constitutive model regarding stress, deformation, dilatancy and damage evolution and healing-effects in two real underground structures in the Asse II salt mine. The simulation results are compared with each other and with measured data. Thereby, an assessment of the capability of the different constitutive models can be given for the disposal of heat- generating radioactive waste in rock salt formations. In the Project numerous specific laboratory tests are carried out for the determination of salt-type-specific parameters as well as the verification of the constitutive models for the thermo mechanical behaviour and healing-effects in rock salt. The Chair of Waste Disposal and Geomechanics participates in this BMWi joint project with its self-developed constitutive model Lux/Wolters and performs healing-tests on rock salt specimens in its rock mechanical laboratory