A Heating Experiment in the Argillites in the Meuse/Haute-Marne Underground Research Laboratory

Abstract

A heating experiment named TER is being conducted with the objectives to identify the thermal properties, as well as to enhance the knowledge on THM processes in the Callovo-Oxfordian clay at the Meuse/Haute Marne Underground Research Laboratory (France). The in situ experiment has being switched on from early 2006. The heater, 3 m length, is designed to inject the power in the undisturbed zone at 6 m from the gallery wall. A heater packer is inflated in a metallic tubing. During the experiment, numerous sensors are emplaced in the surrounding rock and are experienced to monitor the evolution in temperature, pore-water pressure and deformation. The models and numerical codes applied should be validated by comparing the modeling results with the measurements. In parallel, some lab testing have been achieved in order to compare the results given with two different scales (cm up to meter scale). In this paper, we present a general description of the TER experiment with installation of the heater equipment and the surrounding instrumentation. Details of the in situ measurements of temperature, pore-pressure and strain evolutions are given for the several heating and cooling phases. The thermal conductivity and some predominant parameters in THM processes (as linear thermal expansion coefficient and permeability) will be discussed.