Modelling of ventilation experiment in argillaceous rock tunnel

Deep geological disposal is one of the most realistic methods of nuclear waste disposal and argillaceous rocks are being considered as potential host rocks for deep geological disposal. This study starts with performing simulations of a laboratory drying test and a ventilation experiment for Mont Terri underground laboratory. A three-phase and two-constituent hydraulic model is introduced to simulate the processes occurring during tunnel ventilation, including desaturation/resaturation in the rock, real phase change and air/rock interface, and to explore the Opalinus clay parameter set. There is a good agreement between experimental observations and calculation results from other D2011 participant teams. Also it is found that the water content evolution is very sensitive to intrinsic permeability, relative permeability and capillary pressure in clay rock. It indicates that the three-phase and two-constituent hydraulic model is accurate enough and it is a good start for full thermohydromechanical understanding of the ventilation experiment on argillaceous rock.