The Research On Preliminary Support Of The Pipe Roof Technology And Its Effect On Tunnel Under The Highway

Pipe roof pre-support technology can limit the sink of surface and maintain the stratum stab1.Especially in the tunnels or other underground engineerings which pass cross-below the existing highways, railways and other structures,Pipe Roof Method was been widely applied because it has long pre-reinforced distance, high reliability, short construction period and other relative advantages. The project of XiongDong Wan tunnel under the highway is adopted as the example. On the basis of the theory of beam on elastic foundation and set up the double parameters of pipe roof beam on elastic foundation model, to analysis the stress and deformation of the pipe roof. Using three dimensional finite difference software FLAC3D to simulate the pipe roof and the interaction of tunnel excavation, Analysis in Pipe Roof Advance Support case, with the excavation, pipe roof deformation and surface subsidence of the tunnel. On the basis of theoretical analysis, numerical simulation, and presented some Suggestions for design and construction. The main research is as follows:1. Introducing development and application of pipe roof bolting technology at home and abroad, and summarying the research theory on pipe shed advance support;2. Combined with XiongDongWan tunnel design and construction of pipe shed, research the preliminary support of the pipe roof effect mechanism,analysis commonly used pipe roof mechanics model;3. Using FLAC3D numerical analysis software to wear cotton under XiongDongWan Tunnel high-speed wide segment forepoling excavation conducted under simulated, analysis in Pipe Roof Advance Support case, with the excavation, pipe roof deformation and surface subsidence of the tunnel. Meanwhile simulated pipe roof under no circumstances, analysis in Pipe Roof Advance Support case, with the excavation, pipe roof deformation and surface subsidence of the tunnel;4. Through theoretical calculation, numerical simulation method to analyze the deformation of shed pipe tunnel excavation engineering, and the analysis results are applied to practice.