Discussion on the Large Deformation Law of Muzhailing Tunnel in Lanhai Expressway

Abstract

Muzhailing tunnel is a key project of Weiwu section Lanhai Expressway. It is located in the northeastern margin of the Tibetan Plateau. The complex geological enviorments, such as high ground stress, large buried-depth, fault and fold development, soft and fragmented rock, leads to poor self-stabilizing ability. 2# inclined shaft of Muzhailing tunnel is the main object we studied in this paper. During the construction of the tunnel, large deformation, spalling and fall-block occured on the initial support. The accumulated dome sinking vale and peripheral convergence value are large, mainly presented by the vault sinking, wall squeezing, shotcrete spalling, fall-block, and steel arch twisting and so on. In this paper, the law of large deformation of the tunnel is discussed.