Excavation Analysis of Sheshui River Long Pipe-Jacking Tunnel for Gas Transmission Using Numerical Simulation

As one of the types of trenchless excavation, pipe-jacking tunnel is being popularly adopted in the fields of municipal pipeline projects and others'. However, it is rare that the technology of pipe-jacking tunnel is used in petroleum and gas transmission engineering. Taking Sheshui River Pipe-jacking Tunnel that is part of Second West-East Gas Transmission Pipeline Project as example, the Plaxis 3D finite element software was utilized to analyze the stress distribution around the tunnel and settlement features after excavation, which would be useful to guide the safety control of construction. The results showed that the lining structures of pipe sections can generally meet the needs of construction in three different buried depths (13m, 18m and 20m), but the maximum settlement displacement would reach to 1.5–2.0 cm even 2.5 cm in some simulation zones, which called for the enhancement of settlement monitoring.