Abstract: This paper presents a case history of a new socket-type water supply pipe and sewage pipe long-distance culvert excavation project above the No.1 rail transit line of Nantong City. A three-dimensional finite element model was established based on the relative position relationship and structural characteristics between the pipeline and the tunnel. The influence of culvert excavation mode and the length of excavation culvert section on the deformation and disturbance of the rail transit tunnel was simulated and analyzed. The analytical results show that, compared with the sloped open excavation, steel sheet pile supported vertical excavation for long-distance pipeline culvert can significantly reduce the deformation and the disturbance to the lower active tunnel. The deformation of the lower tunnel increases with the length of excavation culvert section. Space-time effect must be considered in the culvert construction. Fast earthwork excavation and backfilling can shorten the exposure time of culvert. The perched water can be excavated with drainage to avoid the overlap of adverse effects of upper unloading and precipitation on the rail transit tunnel. The evaluation results provide an useful reference for construction design of municipal pipeline adjacent to rail transit.

Key words: Rail Transit, Tunnel Deformation, Pipeline Culverts, Numerical Simulation