Abstract: To better study the permeability of rock under complex conditions (high stress, high water pressure, high temperature, and hydrochemical action), we researched and developed a test system coupling thermal, hydrological, mechanical and chemical (THMC) processes. By directly applying temperature field, seepage field, as well as chemical environment, the test system is a brand new system based on the existing stress-seepage coupling test system. On the basis of stress loading system and osmotic pressure control system, we added temperature control system and self-mixing chemical solution system. The maximum axial load of the test system could reach 1 500 kN. By this system, we could perform permeability tests of fractured rock in coupled conditions: high stress (30 MPa), high water pressure (30 MPa), high temperature (150 ℃) or low temperature (-20 ℃), and chemical action (in strong acid or strong alkaline environment). Moreover, we could also perform test coupling rock deformation, rock permeability and stress processes. We applied the proposed system to many coupled permeability tests and verified its reliability.

Key words: permeability test system, coupled THMC processes, permeability, multi-channel control, multi-field coupling tests