Effects of fluid-rock interaction on mechanical behavior of rock salt

摘要

An experimental investigation based on triaxial compression tests, relaxation and creep tests was performed in "wet" condition (without jacket) in order to allow percolation of the confining fluid (brine or oil). Comparison of the results with those obtained in "dry" condition shows that failure and damage criteria in "wet" condition are significantly and systematically lower than those in "dry" condition. Morever, viscoplastic flow is enhanced when damage occurs. The involved fluid/rock interactions are : a mechanical effect due to pore pressure and a chemico-mechanical effect due to salt solubility in brine. These hydro-chemico-mechanical phenomena may play a significant role in the safety assessment of long-term radioactive disposal.