Abstract:

 In order to explore the evolution law of the shear-seepage characteristics of the rock mass in the high pressure hydraulic infiltration zone and fluctuation zone under the coupling action of pressure shear load and fluid infiltration, a new shear-seepage coupling test and shear creep-seepage coupling test were performed on saturated argillaceous shale under different injection water pressures using a new rock shear-seepage coupling test system. The test results show that: 1) With the increase of injection water pressure, the peak shear strength, peak normal deformation and shear creep failure strength of saturated argillaceous shale decrease, which indicates that injection water pressure has a degradation effect on the mechanical strength of rock samples. 2) During the shear-seepage coupling test, the shear stress and normal deformation of the rock sample have obvious up and down fluctuations at the end of the linear elastic change, accompanied by the outflow of water. The sudden changes of shear stress and normal deformation have time-dependent consistency. 3) During the shear creep-seepage coupling test, the seepage rate of water is positively correlated with the injection water pressure. With the increase of the applied level of shear load, the creep deformation of the rock sample is larger and the cumulative amount of seepage water per unit time also increases.

Key words: argillaceous shale, injection water pressure, shear-seepage coupling, test system, mechanical properties