Study on the Deformation and Stability of Surrounding Rock

To rely on nuclear power plant water tunnel project, through the numerical simulation methods, we analysized the extent of rock deformation and stability of the process of excavation and supporting to reveal the deformation near the working face of rock tunnel.The research results show: When carrying out tunnel excavation, the plastic deformation zone in the horizontal direction perpendicular to the tunnel axis and the vertical downward direction are extended, the vault appears to sink, but also occurred in surface subsidence. Contrast the extent of tunnel excavation: The minimum extent is the tunnel axis perpendicular to the vertical downward, followed along the tunnel axis, the maximum extent is perpendicular to the direction of horizontal tunnel axis. Three kinds of excavation methods, a substantial volume reduction of sinking takes place in short steps and extra short steps excavation than the excavation of the top arch , and the surrounding area within the plastic is significantly reduced, which shows the smaller footage of the excavation the better control of the sinking of the crown.