Abstract: Considering especially the influence of the thermal water diffusivity and the isothermal vapor diffusivity on the continuity of water and the energy balance, the author improves further the established control equations for analyzing coupled thermo- hydro-mechanical phenomena in saturated-unsaturated porous media; and makes the numerical simulation for the coupled thermo- hydro-mechanical processes in near field of a conceptual nuclear waste repository by using a FEM code developed by the author and the experiment data; and investigates the changes and distributions of temperature, saturation, pore pressures and principal stresses in the buffer and the rockmass. The part results obtained are compared with the computation data of foreign similar code; and it is shown that the regulations of both results have certain identity qualitatively and quantitatively. and some conclusions are drawn.

Key words: conceptual nuclear waste repository, near field, coupled thermo-hydro-mechanical model, 2D finite element analysis