Thermo-Hydro-Mechanical Coupling Model Research In Saturated Rock Mass

As the important components of physical geologic environment for rock mass, temperature field, seepage field and stress or strain field are coupled, namely coupled Thermal-hydro-mechanical(THM) behaviour, which is highly non-linear and complex. It has extremely important application value in concerning these three coupling functions researches in many domains such as the geothermal resource development, the petroleum engineering, the mining engineering, the underground nuclear waste storage security, the frozen earth and so on. As a result of the differences of the research object, the forms of the THM coupling models exist differences, it is extremely difficult to establish the coupling model conforming to the actual problem, Moreover,at present the entire coupling solving methods are being researched. Therefore, the saturated rock mass is taken as the research object in this paper, with mixed analytic method, and the THM coupling model is established based on the saturated small distortion situation, and calculated to be confirmed through mathematics method and the coupling software.On the base of looking back the research progresses of the model theories in multiphysics fields by domestic and international scholar, the research results in THM are overall elaborated from three aspects including elementary theories, function models and developments. The deficiencies in the THM coupling research are pointed out, and then the main research contents and key points of this paper are proposed. Then. according to the linear thermoelastic theories, the Thermal -hydro -mechanical (THM) coupling mathematics model for saturated bore material are derived, including groundwater flow field controlling equations, rock mass transform field controlling equations and temperature field controlling equations. The effects of changing density along with temperature and pressure and the one of source term (including the effect of temperature gradient and viscous dissipation on water power-mechanics in multi-fields) are taken into account with emphasis. Thirdly, in order to prove the reasonable possibility of model, the mathematics model is carried on number emulation analysis and verification by three ways, which are calculated by one dimensional limited Fourier method, two fields coupling examples verification method and all three fields coupling examples calculation method. The results proves that the model is rationable. Moreover, aiming at demontrating the application, the sensitivities of the model are analyzed through changing the influence factors.Finally,with the Comsol Multiphysics software, the two and all three nonlinear coupling models in THM are carried on emulation, which are permeate-concretion question in two fields coupling analysis, and oil extraction by cold water injected well problem and frozen earth problem in all three coupling fields analysis. Furthermore, the multi-field coupling regulations of rock mass are discussed.