Evolution of Contact State during Shear of Rough Rock Joints and Its Influence on Seepage Characteristics

Abstract

The seepage characteristics of fractured rock mass under compression and shear are one of the important factors affecting the stability of rock mass engineering. In order to understand the effect of shear action on the variation of joint surface aperture and reveal the mechanism of shear action on the seepage behavior of joint surface, in this paper, laboratory tests and numerical simulations were used to study the shear flow in the rough rock joints. Based on the results of shear tests in the laboratory, a numerical seepage model considering the contact mode of joints surface was established by introducing contact mode into the elastic deformation of rock, and the changing trend of the fluid flow characteristics in the shear process was studied. The results show that the numerical model can restore the stress distribution and contact region evolution, and the inhomogeneous distribution and evolution of the apertures are closely related to the distribution and evolution of the fluid flow velocity inside the fracture, with the area of higher flow velocity showing a distribution trend perpendicular to the flow direction. This model can be used to predict the effect of shear on rock seepage in underground projects with fracture surfaces under complex stress conditions, and it is a guide for the study of shear-flow models with rough connection surfaces.