地铁隧道盾构施工力学行为及破坏接近度评价方法研究

发布时间：2018-07-20 20:55

【摘要】：目前针对合肥市区地质条件及周边环境的地铁隧道盾构施工,暂无相应成熟工程经验借鉴。鉴于此,本论文选取合肥轨道交通1号线盾构施工过程中的两个典型工况,即下穿南—环城市隧道及下穿南淝河,开展地铁盾构施工过程的动态数值仿真分析。研究了施工过程中地表变形及地层变形受力情况,运用破坏接近度指标评价隧道周围区域岩土体的稳定性程度,研究典型工况下合肥地铁盾构施工的安全问题,对以后合肥地区的地铁盾构施工具有一定的理论和工程指导价值。本文主要完成的工作有：(1)通过查阅大量国内外文献,总结了国内外学者在盾构施工方面的研究成果,根据研究的背景及目的,阐述了本文的主要研究内容；(2)简要地介绍了盾构施工引起地层变形、流固耦合等基本理论,并且引入了破坏接近度指标,介绍了相关基本理论;(3)针对盾构下穿南一环既有城市隧道施工存在的安全风险,运用FLAC3D实现了隧道盾构开挖的模拟,分析了盾构推进过程中既有城市隧道结构以及在建隧道应力应变分布规律；(4)针对盾构下穿南淝河施工存在的安全风险,运用FLAC3D进行了隧道盾构下穿河流开挖过程的模拟,对比分析了相同条件下的流固耦合和弹塑性计算结果,阐述了水的渗流影响在盾构下穿河流施工稳定性分析中是必须考虑的因素；(5)基于破坏接近度对盾构隧道开挖过程中隧道周边岩土体稳定性进行分析。通过破坏接近度指标可以正确评价隧道周围各区域岩土体的稳定性程度,破坏接近度分布及演化规律对研究施工中应采取的预防措施具有重要的指导意义。
[Abstract]:At present, there is no relevant mature engineering experience for shield tunneling construction of metro tunnel in accordance with the geological conditions and surrounding environment in Hefei. In view of this, this paper selects two typical working conditions of shield tunneling in Hefei Rail Transit Line 1, that is, through the Nanhuan City Tunnel and the Nanfeihe River, to carry out the dynamic numerical simulation analysis of the subway shield construction process. The ground deformation and ground deformation during construction are studied, the stability of rock and soil around the tunnel is evaluated by using the damage proximity index, and the safety problems of shield construction in Hefei metro under typical working conditions are studied. It has certain theoretical and engineering guiding value for the shield tunneling construction in Hefei area. The main works of this paper are as follows: (1) through consulting a large number of domestic and foreign literature, summarized the domestic and foreign scholars in shield construction research results, according to the background and purpose of the study, elaborated the main research content of this paper; (2) the basic theories of ground deformation and fluid-solid coupling caused by shield tunneling are briefly introduced, and the damage proximity index is introduced, and the relevant basic theories are introduced. (3) in view of the safety risks existing in the construction of existing urban tunnels under shield tunneling, The simulation of shield excavation is realized by FLAC3D, and the distribution of stress and strain in the existing city tunnel structure and the tunnel under construction are analyzed. (4) the safety risk of tunneling through Nanfeihe River under shield tunneling is analyzed. FLAC3D is used to simulate the excavation process of river under shield tunneling, and the results of fluid-solid coupling and elastic-plastic calculation under the same conditions are compared and analyzed. The influence of water seepage on the stability analysis of river under shield tunneling is discussed. (5) the stability of surrounding rock and soil in shield tunnel excavation is analyzed based on the degree of damage proximity. The stability degree of rock and soil around the tunnel can be correctly evaluated by the damage proximity index. The distribution of failure proximity and the law of evolution have important guiding significance for the study of preventive measures to be taken in construction.
【学位授予单位】：合肥工业大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：U455.43;U231.3

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