Influence of pore water compressibility on the short and long term stability of nuclear waste disposal galleries in clay

In soils, pore water may contain some dissolved air or gas, which significantly reduce its bulk modulus. The paper deals first with the hydro-mechanical behaviour of a clay mass during and after the excavation of a gallery. It especially points out the influence of pore water compressibility compared to soil stiffness on the damaged zone extent and the dissipation of pore pressures. Afterwards, thermo-hydro-mechanical simulations of a high-level nuclear waste disposal are presented, emphasizing again the part taken by the pore water bulk modulus