地铁盾构区间隧道近接下穿综合管廊影响研究

Analysis on Influence of Metro Shield Section Passing under Utility Tunnel

地铁盾构区间隧道施工下穿既有综合管廊时,周围土体产生扰动,引起周围土体的变形,会使既有综合管廊产生附加应力和变形,威胁结构安全。为了研究盾构隧道下穿过程中对既有综合管廊的影响,探索不同穿越交角下既有管廊的变形规律,采用三维有限差分法进行模拟,分析盾构隧道施工过程中既有综合管廊的沉降变形规律、地基加固对管廊沉降的控制效果及不同下穿交角对既有综合管廊沉降的影响。计算结果表明:既有综合管廊在盾构机附近主要产生纵向上的不均匀沉降,随着盾构掘进,沉降逐渐增大,进行地基加固后能够有效减小既有管廊的沉降变形。当下穿交角较小时,既有综合管廊沉降变形增大。通过本文的研究,可以为类似工程提供指导。

When the tunnel construction of metro shield section passes under the existing utility tunnel,the surrounding soil is inevitably disturbed,which will cause the deformation of surrounding soil,and will make the existing utility tunnel cause the additional stress and deformation,and threaten the safety of structure.In order to analyze the influence on the existing utility tunnel in the shield tunneling process,the deformation law of existing utility tunnel at the different crossing angles is explored.The three-dimensional finite difference method is used to simulate and analyze the settlement and deformation laws of the existing utility tunnel,the control effect of ground reinforcement to settlement of utility tunnel,and the influence of different crossing angles on settlement of existing utility tunnel in the process of shield tunneling.The calculation results show that the longitudinal uneven settlement of existing utility tunnel mainly occurs near the shied tunneling machine.With the shield tunneling,the settlement increases gradually.The ground reinforcement can effectively decrease the settlement and deformation of the existing utility tunnel.When the downward crossing angle is small,the settlement deformation of existing utility tunnel increases.The study result can provide the guidance for similar projects.