Numerical modelling of moisture controlled laboratory swelling/shrinkage experiments on argillaceous rocks

Moisture-induced swelling and shrinkage deformation is a well-known phenomenon for clayey material. To quantify this deformation a fully coupled thermal-hydro-mechanical (TH2M) model based on the modified effective stress concept has been developed and implemented in the numerical code OGS. Three laboratory tests have been analysed using this concept. All specimens for the tests are argillaceous rocks, from different underground laboratory sites (Tournemire, Bure, France, and Mont Terri, Switzerland). The laboratory tests are performed under different conditions; the first test is free swelling/shrinkage and other two tests are with uni-axial loading. The relative humidity is also controlled. Only one test is carried out under varied temperature conditions. In this study the anisotropic swelling/shrinkage deformation wais simulated and analysed using this modified effective stress concept.