Treatment and exploitation of time series of pressure and temperature obtained in the Tournemire URL

Compacted argillaceous semi-permeable are potential geological formations for the deep repository of radioactive wastes, due to their very low permeability and to their capacity of radionuclide retention. In this framework, IRSN develops its own research programmes in its experimental station of Tournemire (Aveyron, France). This laboratory is located in a century-old tunnel crossing an argillite formation 250 m thick from Toarcian and Domerian. Since 1990, 18 boreholes have been realized with the aim of acquiring among others, the hydraulic characteristics of the argillaceous formation and of its bounding aquifers. Seven boreholes, equipped with twenty sensors, have been followed for the pressure and temperature of the pore and fracture waters with an acquisition each half of an hour. The barometric pressure and temperature in the tunnel were also recorded in the same period. The aim of this work was to treat all of these time series by means of mathematical tools with the goal of extracting signals emitted at the massif scale and likely to inform us about its global hydraulic functioning. This information will be compared to that acquired, at the very local scale, by hydraulic tests. (authors)