关键词: 零跨距, 立体交叉隧道, 变形, 折减系数

Abstract: This paper presents a case history of an actual operating of a zero-distance interchange tunnel. The numerical method is adopted to carry out simulation of the entire cross integrated tunnel construction process at different span distances to explore the deformation characteristics of the zero-distance interchange tunnel. The results show that: (1) Span length changes have a significant impact on the deformation of the surrounding rock mass. The deformation process of the mid-rock mass in the three-dimensional cross-area is presented a three stage changes: a sharp increase-reduced displacement-gradual stable; (2) The span length reduction of the first level transfer of the opposing body’s cross area has a significant effect, and the final stage displacement and changes in different parts of different parts are large. (3) The deformation of the tunnel’s left opening and the bottom of the oblique shaft is the most sensitive to changes to the discount coefficient. The zero distance interchange tunnel has sufficient safety backups, and the surrounding rock mass and the initial support are within the allowable range.

Key words: Zero Span, Interchange Tunnel, Deformation, Reduction Coefficient ,  ,