3DEC Numerical Analysis of Failure Characteristics for Tunnel in Stratified Rock Masses

3DEC is used herein to study the stability of a circular tunnel opening in stratified rock mass. Numerical analysis indicated that the bedding planes can influence the damage process and the distribution of secondary cracks in rock masses, creating more damaged zones. The bedding planes lead to a nonuniform distribution of water pressure behind the lining. Such nonuniform water pressure may result in localized damage in the tunnel. Water leakage occurs mainly at the top of the tunnel and on both side of the walls. Tunnels situated in vertical bedding planes are more vulnerable to water, especially for underwater projects such as water diversion tunnels and undersea tunnels, where construction in vertical bedding planes should be avoided as much as possible. The maximum deformation of shotcrete occurs at the intersection with the bedding plane, and the displacement on the upper side is greater than that on the lower side.