沿街城市浅埋隧道的三维施工效应分析

采用三维有限元方法动态模拟了城市地下沿街浅埋隧道的施工过程,分析和探讨了在此过程中引起的地层应力、地面沉降、地表超前沉降和隧道围岩变形特征,并与实测值进行比较。研究结果表明:在掌子面向前推进时,拱顶沉降受其影响的墙后距离约为2.5B (B为隧道净宽);拱顶产生的最大沉降量随开挖面的推进在逐渐增大;有限元模拟结果与实测值相吻合,由于没有考虑地下水等因素的影响其小于实测值。其分析结果具有一定的理论和实际意义,为相似工程提供了借鉴和指导。

3D Simulation and Analysis on Effect of Construction Process of Urban Shallow Tunnel

By using 3D finite element method to simulate the construction process of urban underground street tunnel, the stratum displacement, ground settlement, advance settlement of ground and the tunnel deformation are analyzed and discussed, and also compared with their measured values. The results show that: in the developing of tunnel face, the influencing region from vault settlement is about 2.5B (B is tunnel clearance ); the largest settlement of vault produced gradually and increased with the excavation face advance; finite element simulation results are identical with the measured values, because without considering the influence of groundwater, leading to that the results are smaller than the measured value. Analysis results have certain theoretical and practical significance for similar project and provide reference and guidance in their work.