地铁盾构施工对既有桥隧影响的力学行为模拟研究

发布时间：2018-03-10 06:57

本文选题：地铁隧道　切入点：盾构　出处：《合肥工业大学》2015年硕士论文　论文类型：学位论文

【摘要】：目前国内外关于地铁隧道同时下穿高架桥桩和城市下穿隧道的工程较少,地铁隧道在复杂条件下设计与施工面临新的挑战。因此对于同时具有市政高架和城市下穿隧道环境下盾构施工对周边建构物影响的研究具有积极的意义。本文针对合肥地铁1#线盾构近距侧穿城市高架桥桩和下穿城市既有隧道施工存在的巨大安全隐患,采用数值模拟和现场监测对比相结合的方法,分析盾构推进过程中不同工况下城市下穿隧道和桥桩结构受力、变形及地层沉降的变化规律。探讨了桩实体单元弯矩、剪力计算方法的可行性。研究成果表明：(1)掘进过程中,盾构机从盾头进入下穿隧道影响区到盾尾离开下穿影响区过程中,盾构掘进对下穿隧道结构的变形和应力的影响较大。且双线开挖,既有建构筑物的变形和应力在盾构的影响下有叠加效应。(2)通过对实体桥桩离散监控点位移的监控拟合,计算出盾构穿越时高架桥桩的弯矩和剪力的方法是可行的。(3)近距离盾构施工对高架桥桩的影响较小,桥桩外提前设置的钢套筒对桥桩起到了较理想的保护作用。(4)在盾构施工的影响下,城市下穿隧道会对距离较近的高架桥桩的应力与变形起到一定的约束作用。(5)桩基、承台及下穿隧道的存在,能一定程度上控制地表沉降。(6)通过对计算结果和监测结果得出的结论对工程实际施工提出一些建议和措施。
[Abstract]:At present, there are few projects at home and abroad about the subway tunnel passing through the viaduct pile and the city tunnel at the same time. The design and construction of subway tunnel under complex conditions are facing new challenges. Therefore, it is of positive significance to study the influence of shield construction on the surrounding construction under both municipal elevated and urban underpass tunnel environment. There are huge hidden dangers in the construction of the shield tunnel in Hefei subway line, which can penetrate the city viaduct pile at short distance and the existing tunnel under the city. Using the method of numerical simulation and field monitoring and contrast, this paper analyzes the changing law of force, deformation and ground settlement of tunnel and bridge pile structure under different working conditions during shield tunneling, and discusses the bending moment of solid element of pile. The feasibility of shear calculation method. The research results show that during the tunneling process, the shield machine enters the tunnel influence area from the shield head into the tunnel, and the shield tail leaves the influence area. The effect of shield tunneling on the deformation and stress of the tunnel structure is great, and the deformation and stress of the existing building structure have superposition effect under the influence of shield tunneling, and the displacement of discrete monitoring points of solid bridge pile is monitored and fitted by double-line excavation. It is feasible to calculate the bending moment and shear force of the viaduct pile when the shield is crossing. 3) the influence of the short distance shield construction on the viaduct pile is less. Under the influence of shield construction, the tunnel under the city will restrain the stress and deformation of the nearby viaduct pile to a certain extent. The existence of cap and underpass tunnel can control the ground subsidence to a certain extent) some suggestions and measures are put forward through the conclusion of calculation and monitoring results.
【学位授予单位】：合肥工业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U455.43;U231.3

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