盾构隧道下穿施工对既有桥梁桩基础的影响及其控制技术研究
发布时间：2018-12-17 00:19
【摘要】：近年来地下交通的极大发展使得地铁线路日益网络化、规模化,地铁线路与既有公路桥梁交叉的情况愈发常见。目前,国内外尚缺乏盾构隧道下穿桩基础工程的相关技术规范,相关学者虽已对盾构隧道下穿既有桥梁桩基础工程问题开展了大量研究工作,但由于盾构施工技术工艺、穿越形式和地质条件的复杂性以及现有研究水平的局限性,取得的研究成果尚不系统,有待进一步研究。论文依托广佛环线沙堤隧道下穿佛开高速公路汾江大桥实体工程,采用资料调研、理论分析与数值仿真计算等方法研究盾构隧道下穿施工对地层变形和既有桥梁桩基础承载特性、受力与变形特性的影响,在此基础上,建立系统的盾构隧道下穿既有桥梁桩基础施工影响控制技术体系。主要成果如下:1)探明了盾构隧道下穿施工对地层及既有桥梁桩基础的影响机理。盾构隧道下穿既有桥梁桩基础过程中,盾构隧道、地层与既有桥梁桩基础处于一个共同作用的体系,隧道施工是扰动来源,地层变形是扰动媒介,既有桥梁桩基础是扰动对象。控制盾构隧道下穿施工对既有桥梁桩基础影响的关键是有效限制盾构隧道施工引起的地层变形。2)对盾构掘进过程进行数值仿真计算,全面分析盾构施工不同掘进阶段、盾构隧道与既有桩基础相对位置、隧道围岩条件等因素影响下地层变形以及既有桥梁桩基础附加变形与附加内力等方面的规律,得到以下结论:(1)地层距盾构隧道越近受到的扰动越强,反之越弱。(2)地层中桩基础的存在对盾构隧道施工扰动的传递起到一定的遮蔽作用。(3)盾构隧道从既有桩基础正下方穿过或从其一侧穿过且隧道顶与桩底平齐时对既有桩基础影响最大;盾构隧道与既有桩基础水平间距超过3倍隧道直径或既有桩基础桩端位于盾构隧道轴线以下时,既有桩基础受盾构施工扰动较小。(4)随着盾构隧道围岩条件的降低,地层沉降槽整体沉降以及既有桩基础的附加沉降、附加水平位移、附加弯矩呈增大趋势。3)根据实施对象的不同,选取针对盾构隧道下穿既有桥梁桩基础工程中的扰动来源(隧道施工)、扰动媒介(地层变形)和扰动对象(既有桩基础)的施工影响控制技术措施,建立了盾构隧道下穿既有桥梁桩基础施工影响控制技术体系。论文研究成果可为今后类似盾构隧道下穿既有桥梁桩基础工程的设计和施工提供指导,具有一定的理论和工程实用价值。
[Abstract]:With the rapid development of underground traffic, subway lines become more and more networked and large-scale, and the intersection between subway lines and existing highway bridges becomes more and more common. At present, there is still a lack of relevant technical specifications for tunneling pile foundation engineering under shield tunnel at home and abroad. Although scholars have carried out a lot of research work on pile foundation engineering of existing bridges under shield tunnel, but due to the technical technology of shield tunneling construction, The complexity of the traversing form and geological conditions and the limitations of the existing research level, the research results obtained are not systematic and need further study. Based on the solid project of Fen River Bridge under the tunnel of sand dike of Guangfo Ring Line, the paper adopts data investigation, Theoretical analysis and numerical simulation are used to study the influence of underpass construction of shield tunnel on ground deformation, bearing characteristics, bearing force and deformation characteristics of existing bridge pile foundation. A systematic control system for the influence of the construction of the existing bridge pile foundation under the shield tunnel is established. The main results are as follows: 1) the influence mechanism of shield tunnel underpass construction on stratum and existing bridge pile foundation is investigated. In the process of tunneling under shield tunnel through existing bridge pile foundation, shield tunnel, stratum and existing bridge pile foundation are in a system of common action. Tunnel construction is the source of disturbance, stratum deformation is disturbance medium, and existing bridge pile foundation is disturbance object. The key to control the influence of tunneling under shield tunneling on existing bridge pile foundation is to effectively limit the formation deformation caused by shield tunnel construction. 2) the numerical simulation calculation of shield tunneling process is carried out, and the different tunneling stages of shield tunneling are comprehensively analyzed. The relative position of shield tunnel and existing pile foundation, the law of ground deformation under the influence of tunnel surrounding rock condition and the additional deformation and additional internal force of existing bridge pile foundation, etc. The following conclusions are obtained: (1) the closer the stratum is to the shield tunnel, the stronger the disturbance is. The contrary is weaker. (2) the existence of pile foundation in stratum has a certain shielding effect on the transmission of shield tunnel construction disturbance. (3) the shield tunnel passes directly under the existing pile foundation or through one side of it and the tunnel top and pile When the bottom is horizontal, it has the greatest influence on the existing pile foundation; When the horizontal distance between shield tunnel and existing pile foundation is more than 3 times the diameter of tunnel or the pile end of existing pile foundation is below the axis of shield tunnel, the disturbance of existing pile foundation by shield construction is small. (4) with the decrease of surrounding rock condition of shield tunnel, The whole settlement of the ground settlement trough and the additional settlement of the existing pile foundation, the additional horizontal displacement and the additional bending moment show an increasing trend. 3) according to the different objects of implementation, This paper selects the construction influence control measures for the disturbance source (tunnel construction), disturbance medium (stratum deformation) and disturbance object (existing pile foundation) in shield tunneling through existing bridge pile foundation engineering. The construction influence control system of the existing bridge pile foundation under shield tunnel is established. The research results of this paper can provide guidance for the design and construction of similar shield tunneling under the existing bridge pile foundation in the future, and have certain theoretical and engineering practical value.
【学位授予单位】：长安大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U455.43;U443.15
本文编号：2383303
[Abstract]:With the rapid development of underground traffic, subway lines become more and more networked and large-scale, and the intersection between subway lines and existing highway bridges becomes more and more common. At present, there is still a lack of relevant technical specifications for tunneling pile foundation engineering under shield tunnel at home and abroad. Although scholars have carried out a lot of research work on pile foundation engineering of existing bridges under shield tunnel, but due to the technical technology of shield tunneling construction, The complexity of the traversing form and geological conditions and the limitations of the existing research level, the research results obtained are not systematic and need further study. Based on the solid project of Fen River Bridge under the tunnel of sand dike of Guangfo Ring Line, the paper adopts data investigation, Theoretical analysis and numerical simulation are used to study the influence of underpass construction of shield tunnel on ground deformation, bearing characteristics, bearing force and deformation characteristics of existing bridge pile foundation. A systematic control system for the influence of the construction of the existing bridge pile foundation under the shield tunnel is established. The main results are as follows: 1) the influence mechanism of shield tunnel underpass construction on stratum and existing bridge pile foundation is investigated. In the process of tunneling under shield tunnel through existing bridge pile foundation, shield tunnel, stratum and existing bridge pile foundation are in a system of common action. Tunnel construction is the source of disturbance, stratum deformation is disturbance medium, and existing bridge pile foundation is disturbance object. The key to control the influence of tunneling under shield tunneling on existing bridge pile foundation is to effectively limit the formation deformation caused by shield tunnel construction. 2) the numerical simulation calculation of shield tunneling process is carried out, and the different tunneling stages of shield tunneling are comprehensively analyzed. The relative position of shield tunnel and existing pile foundation, the law of ground deformation under the influence of tunnel surrounding rock condition and the additional deformation and additional internal force of existing bridge pile foundation, etc. The following conclusions are obtained: (1) the closer the stratum is to the shield tunnel, the stronger the disturbance is. The contrary is weaker. (2) the existence of pile foundation in stratum has a certain shielding effect on the transmission of shield tunnel construction disturbance. (3) the shield tunnel passes directly under the existing pile foundation or through one side of it and the tunnel top and pile When the bottom is horizontal, it has the greatest influence on the existing pile foundation; When the horizontal distance between shield tunnel and existing pile foundation is more than 3 times the diameter of tunnel or the pile end of existing pile foundation is below the axis of shield tunnel, the disturbance of existing pile foundation by shield construction is small. (4) with the decrease of surrounding rock condition of shield tunnel, The whole settlement of the ground settlement trough and the additional settlement of the existing pile foundation, the additional horizontal displacement and the additional bending moment show an increasing trend. 3) according to the different objects of implementation, This paper selects the construction influence control measures for the disturbance source (tunnel construction), disturbance medium (stratum deformation) and disturbance object (existing pile foundation) in shield tunneling through existing bridge pile foundation engineering. The construction influence control system of the existing bridge pile foundation under shield tunnel is established. The research results of this paper can provide guidance for the design and construction of similar shield tunneling under the existing bridge pile foundation in the future, and have certain theoretical and engineering practical value.
【学位授予单位】：长安大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U455.43;U443.15
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相关期刊论文 前2条
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，本文编号：2383303
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