Experimental And Numerical Study On The Thermo-Hydrological Coupling Of Fractured Rocks

This paper based on the background of the studies for the deep geological disposal of high level radioactive waste (HLW), researched the characteristics of fractured rocks under heating and flow coupling conditions. The major contents are as follow:(1)Large-scale fractured rocks model. The model was made up with eighteen blocks of granite of Beishan region, involved two pairs of relatively non-filled fractures distributed along the horizontal and vertical line uniformly. The conditions applied to the model were right boundary heating and vertical flow. A experimental program under right boundary heating and vertical flow conditions was carried out and the results included fracture character and hydrological properties, temperature distribution of rock mass at different and heating temperatures.(2)Against laboratory experiment, the coupled processes of conductive, convective and dispersive heat transport; and nonisothermal fluid flow were simulated by FLAC software.Through analyzing and comparing the results calculated using finite-element codes and the experimental results, it indicated that both results are quite anastomotic. It is concluded that (1) In experimental model, transportation of energy arise mainly through the fluid flow in vertical fractures; (2) heat convection significantly affects the distribution of temperature in fractured rocks; (3)the predominant effect is the nonisothermal fluid flow in fractures; (4) seepage field restrictes extent of temperature distribution influenced by the change of heating boundary in fractured rocks.