Abstract: The topic on the seepage-stress coupling characteristics of jointed rock mass is generally considered as an important and difficult research direction in the field of rock mechanics. The natural jointed rock mass commonly exists in the three unequal compressive stress states in water conservancy and hydropower engineering and underground engineering. There are limited studies on the seepage-stress coupling characteristics of jointed rock mass under the states of three principal stresses. The fundamental study should focus on the seepage-stress coupling characteristics of the monolithic rock mass. In this study, the effect of lateral stress and the seepage mechanism of monolithic rock mass were analysed and explored. Then the theoretical formula of its seepage-stress coupling characteristics was deduced on the basis of the existing permeability-stress analytical model. Theoretical results were also compared with experimental results from true triaxial seepage-stress coupling tests in the laboratory. The rationality of the derived formula was verified by the global optimisation nonlinear fitting method and the block discrete element method (DEM). The similar physical quantities of analog circuits and seepage problems were obtained by using the circuit principle. The seepage-stress coupling characteristics of jointed rock mass with a regular hexagonal joint network were preliminarily investigated by introducing the equivalent seepage resistance method. The obtained results provide useful references for seepage analysis of rock mass in practical engineering.

Key words: jointed rock mass, three principal stresses, seepage-stress coupling, water flow in a single joint, columnar joint