Numerical Simulation of Coal Seam Floor Under Multi-field Coupling

This article presents a THM (Thermal–Hydrological–Mechanical) coupling model for the temperature field, seepage field, and stress field of rock masses. The study investigates the inherent effects of various structural rock masses when subjected to the coupling of tectonic stress field, rock mass temperature field, and groundwater seepage field. Firstly, the connected THM model's governing equation was formulated by integrating the equations related to solid deformation, seepage control differential, mechanics, and heat transfer. Secondly, the coupling model is built by setting boundary conditions. Finally, the model was numerically simulated using COMSOL Multiphysics. The results showed that under the coupling effect of stress seepage temperature, there is almost no effect on the geothermal in the promoting process of the production, whereas the seepage field has a great influence on the temperature distribution, and the temperature contour will move toward the seepage velocity. The faster the seepage velocity is, the greater the influence on the geothermal gradient is, and the more obvious the influence on the temperature distribution.