Stability Analysis of Surrounding Rock of Tunnel in Consideration of Anisotropic Strength of Rock Mass

Surface of discontinuities as joint and fissure are ubiquitous in rock masses.The surface of discontinuities significantly affect the strength of the rock masses.According to the physical and mechanical characteristics of joint and rock matrix,the theory and method were studied for anisotropic strength criteria of rock mass.Based on the Drucker-Prager criterion and stress-based joint opening criterion,a composite constitutive model of rock mass with densely distributed joint was proposed and it can depict the anisotropic characteristics of rock strength and progressive failure characteristics.The proposed model was used to simulate the construction of tunnel.Results show that the model can be used to explain deformation and failure phenomenon of the surrounding rock fairly,which are in accordance with engineering practice.The study give a reference to exploitation of underground oil,preservation of nuclear waste and design and construction of underground engineering in China.