盾构隧道施工对邻近地铁线路的扰动影响及防护措施研究

Shield Broussonetia Papyrifera Study on Disturbance Effects and Protective Measures of Tunnel Construction on Adjacent Subway Lines

摘要: 随着城市轨道交通网络密集化发展，盾构隧道近距离穿越邻近地铁线路的工程场景日益增多，施工扰动易导致地铁结构变形、轨道平顺性下降，威胁运营安全。为揭示扰动影响规律并提出针对性防护技术，本文通过理论分析、数值模拟与工程案例结合的方法开展研究：明确盾构施工扰动的核心机理(地层损失、应力重分布、地下水扰动)；系统分析地层条件、施工参数、邻近距离等关键影响因素；构建“源头优化–过程调控–工程防护”三级防护体系；结合某城市盾构隧道穿越地铁3号线工程案例验证措施有效性。研究表明：盾构施工对邻近地铁的最大沉降影响出现在掌子面通过后7~10天，净距≤3 D (D为盾构直径)时扰动显著加剧；采用“地层预处理 + 隔离桩防护 + 动态参数调控”复合措施后，地铁结构沉降量控制在3 mm以内，满足GB 50446-2017规范要求。本文成果可为盾构隧道近距离穿越地铁线路的施工设计与安全管控提供理论支撑和工程参考。

Abstract: With the intensive development of urban rail transit networks, engineering scenarios where shield tunnels cross adjacent metro lines at close distances have become increasingly common. Construction disturbance is prone to causing deformation of metro structures and a decline in track regularity, threatening operational safety. To reveal the law of disturbance impact and propose targeted prevention and control technologies, this study is conducted using a combination of theoretical analysis, numerical simulation, and engineering cases: the core mechanisms of shield construction disturbance (stratum loss, stress redistribution, groundwater disturbance) are clarified; key influencing factors such as stratum conditions, construction parameters, and adjacent clear distance are systematically analyzed; a three-level prevention and control system of “source optimization - process regulation - engineering protection” is established; the effectiveness of the measures is verified through an engineering case of a shield tunnel crossing Metro Line 3 in a certain city. The results show that the maximum settlement impact of shield construction on adjacent metro lines occurs 7~10 days after the tunnel face passes, and the disturbance intensifies significantly when the clear distance ≤ 3D (D is the shield diameter); after adopting the composite measures of “stratum pre-treatment + isolation pile protection + dynamic parameter regulation”, the settlement of the metro structure is controlled within 3 mm, which meets the requirements of GB 50446-2017 Code. The results of this study can provide theoretical support and engineering reference for the construction design and safety management and control of shield tunnels crossing metro lines at close distances.