Numerical simulation on deformation and failure of surrounding rock in high in-situ stress and its verification in physical model

Structure and support failures of tunnels are common problems for deep tunnels in high in-situ stress rock masses and they have more requirement on support designing. Based on the alteration of surrounding pressure and the strength of engineering rock mass, the mechanism of deformation and failure of surrounding rocks of the tunnel constructed in high in-situ stress rock masses is studied. According to rock character of a certain tunnel of Chongqing, the Mohr-Coulomb criterion with tension cut-off strain- softening model is adopted, a three-dimensional nonlinear simulation for it has been carried out. The distribution of plastic zones, tensile stress zones ,displacements and the progressive failure of the surrounding rock is analyzed , the failure law of the surrounding rock in high in-situ stress. For application in site ,the physical model results is used and the results agree with the numerical model.