Study on long term hydro-mechanical coupled behavior of Belgium Boom Clay

The phD thesis focused on the laboratory and numerical investigation on the long-term hydro-mechanical coupled behavior, creep damage behavior of Boom Clay. The main achievements are stated as follows: 1) Laboratory works: short-term and long term Oedometer and triaxial tests on Boom clay. The variation of micro structure before and after the shearing tests was studied by SEM. The experimental results highlighted the creep potential of Boom Clay and indicated that the creep rate of Boom clay is about 10-5 /h, the deviatoric stress threshold of the creep is about 1 MPa. (2) numerical works : a) A transversely isotropic elasto-plastic damage constitutive model, a nonlinear creep damage constitutive model were developed. The former one can describe the hardening and softening behavior of Boom Clay. The later one can describe the nonlinear creep damage process of Boom clay very well .The corresponding parameters are obtained from triaxial test results by inverse analysis and analytical method. b) Based on the above development, 3D numerical analysis of the long term in situ measurements (pore water pressure and convergence of the tunnel) around HADES has been conducted. Good agreement between numerical one and in situ monitoring was obtained.