Modelling of the hydro-mechanical behaviour of the Bure argillite

During the construction and the exploitation phase of the waste disposal, and after its closure, the rock mass will be submitted to various thermo-hydro-mechanical loadings. The rock, initially saturated, will partially de-saturate due to the ventilation of the galleries. The drying could generate tensile stresses at the galleries wall; however drying will also increase the rock strength and the creep strain rate will be made slower. In order to predict the short-term and long-term responses of the rock, laboratory experiments are conducted to build models and to determine the corresponding parameters which will be used to perform predictive numerical simulations. The hydro-mechanical models must be able to describe the transition between the saturated and unsaturated states. This paper deals with the modelling of some aspects of the unsaturated hydro-mechanical behaviour and transport properties of this argillite on the basis of the interpretation of laboratory experiments performed at different relative humidities