Evaluation of a thermal criterion for an engineered barrier system

摘要

The retention curve of French FoCa compacted clay has been determined at 20, 50 and 80 deg C. A saline saturated solution has been used to control the suction. The temperature, up to 80 deg C, has no influence on the e(P_c) curve. On the other hand, the water content and the liquid saturation degree are lower at 50 or 80 deg C than at 20 deg C. A model is proposed to take into account the influence of the temperature, in the framework of Biot's theory. A method to determine the liquid permeability of an unsaturated porous media is proposed. It is based on an analytical solution and on an experimental survey of the transient phase of desorption. This method has been applied to the compacted FoCa clay, at 20 deg C. It is easy to implement and efficient. The permeability of FoCa clay has been determined for a large range of suctions.