Small Radius, The Slope Of Shield Tunneling Mechanical Properties Studied

Recently, the shield-driven tunnel has been constructed in the soft soil of cities, which bring forward some new problems at the same time.For example, special shield-driven tunnel need to be excavated on small radius curve and big gradient route. Based on the construction of NO.4 subway in Guangzhou, this paper adopted numerical calculation, theoretical analyses and relevant source in situ, focused on the mechanics characters of the two special conditions during the advancing process.The content of this paper will be concentrated on:1. According to the in situ-data of NO.4 subway in Guangzhou, some parameters that influence the shield-driven construction are summed up, including the driven velocity, moment, injecting pressure.2. The sensitivity of Parameters that influence the displacement of ground is analyzed by numerical simulation, and the result indicates that earth pressure, the efficiency of injecting effect it greatly.3. The difference of GAP between the beeline and the curve is compared by adopting numerical simulating, and mechanics characters of shield-tunnel on small radius route are analyzed through three aspects: displacement of the earth's surface, plastic scope of the excavation face and internal force of lining.3. Based on silo model, the expression of supports that maintain the equilibrium of excavation face on big gradient route is deduced. The supports under different gradient are compared by concrete example. At the same time, stress and displacement around excavation face are also discussed in simulation model.