Abstract:Based on the differential control equations of the coupled thermo-hydro-mechanical(THM) processes of dual media,this paper presented three-dimensional coupled model of dual media to research coupled THM of fractured rock masses. In the coupling model,the values of nodal displacement,water pressure and temperature were solved in different media. Strategy and methods to solve this mathematical model also were discussed. A three-dimensional FE codes for analysis of coupled THM processes of dual media were developed tentatively. Through the numerical computation for a coupling THM phenomenon in the heat exploitation of deep-seated HDR 2 200 m under the surface,it was shown:(1) coupling THM processes was obvious in the rock mass near injection wall;(2) trunk fractures will influence the distribution of seepage field,temperature field and stress field remarkably. Compared with hydro-mechanical coupled model and thermo-mechanical coupled model,the remarkable or unremarkable interactions between three fields were studied. It is also displayed:(1) dominant double coupling system occurs in the certain space time;(2) temperature field remarkably has effects on fracture seepage field under changeable temperature condition. The importance of coupled THM processes was highlighted.