NUMERICAL SIMULATION OF STRESS AND DEFORMATION OF THE SURROUNDING ROCK IN DEEP-BURIED TUNNEL AT DIFFERENT LATERAL PRESSURE COEFFICIENT

Taking the round tunnel and square tunnel as an example, the stress and deformation of the surrounding rock in deep-buried tunnel at different lateral pressure coefficient are simulated by FLAC3D.The research showed that the stress and deformation are relationship with the side pressure coefficient. When 1,the maximum of major principal stress and shear strain increment of the surrounding rock are located in the left and right sides of the tunnel, the maximum of displacements are located in the top of the tunnel, meanwhile, the distribution of the shear strain increment is approximately like an oval with it's longer axis are parallel to the Z-axis; When 1,the maximum of major principal stress and shear strain increment of the surrounding rock are located in the top and bottom of the tunnel, the maximum of displacements are located in the left and right sides of the tunnel, the distribution of the shear strain increment is approximately like an oval with it's longer axis are parallel to the X-axis. Furthermore, the variation law of major principal stress, shear stress, displacements and shear strain increment of the surrounding rock at different lateral pressure coefficient were analyzes and obtained. The research results can be helpful to the study on the relationship between horizontal stress and cavern excavation; also, it can be useful on the selection of cross sectional shape of tunnel.