基坑开挖对侧方地铁盾构隧道的变形影响及控制措施研究

发布时间：2018-01-08 03:07

本文关键词：基坑开挖对侧方地铁盾构隧道的变形影响及控制措施研究　出处：《华南理工大学》2014年硕士论文　论文类型：学位论文

【摘要】：地铁沿线高强度、高密度的物业开发，必然会产生大量的深基坑工程，邻近地铁侧方深基坑开挖便是其中最常见的一种外部作业形式。由于开挖卸荷量大，使得周边土体的位移场和应力场变化较大，加之所处工程地质条件的复杂性，施工过程中极易诱发盾构隧道管片开裂、渗漏水、接缝张开等病害，从而影响地铁的结构安全及正常运营。目前关于基坑开挖对侧方地铁隧道的影响多针对单一工程实例展开，且以盾构隧道变形量为控制目标的基坑变形控制研究还不够完善，因此，研究基坑施工对邻近盾构隧道的变形影响规律，并根据盾构隧道保护标准采取针对性的基坑变形控制措施，是有效实现地铁隧道安全保护的关键。本文采用有限元数值分析方法，系统地研究了基坑开挖对侧方盾构隧道的变形影响，并分析了控制地铁隧道变形的相关措施及其工程应用。具体作了如下方面的研究：（1）调研了广州地铁侧方基坑开挖对既有盾构隧道影响的工程实例，分析了盾构隧道的横向变形及纵向变形特征，总结了基于Mindlin解和Winkler地基梁理论求解盾构隧道纵向变形的方法。（2）基于有限元法模拟分析了基坑开挖全过程对侧方盾构隧道的影响，重点分析了支护结构的变形及受力变化、隧道的横向变形、纵向变形特点及受力变化情况。（3）分析了侧方地铁盾构隧道变形的相关影响因素，并研究了基坑水平净距、盾构隧道埋深变化、基坑开挖深度、基坑支护体系刚度、基坑方位及尺寸变化、逆作法施工的影响；研究了开挖卸荷下不同影响因素对侧方盾构隧道的变形影响规律。（4）提出了地铁隧道侧方基坑变形控制值的确定流程，并在本文算例基础上计算特定条件（水平净距、埋深等）下对应的基坑变形控制值。最后，，总结并分析了地铁盾构隧道侧方基坑的变形控制措施及其工程应用情况。
[Abstract]:High intensity and high density property development along the subway will inevitably produce a large number of deep foundation pit projects, adjacent to the subway side deep foundation pit excavation is one of the most common form of external operation, because of the large amount of excavation unloading. The displacement field and stress field of surrounding soil are changed greatly, in addition to the complexity of the engineering geological conditions, the shield tunnel segment cracking, water leakage, joint opening and other diseases are easily induced in the construction process. Thus affecting the subway structure safety and normal operation. At present, the influence of foundation pit excavation on lateral subway tunnel is mostly focused on a single engineering case, and the research on foundation pit deformation control with shield tunnel deformation as the control target is not perfect, so. It is the key to effectively realize the safety protection of subway tunnel to study the influence of foundation pit construction on the deformation of adjacent shield tunnel and to take appropriate measures to control the deformation of foundation pit according to the protection standard of shield tunnel. In this paper, the influence of excavation on the deformation of side shield tunnel is systematically studied by using finite element numerical analysis method. The paper also analyzes the relative measures of controlling the deformation of subway tunnel and its engineering application. 1) an engineering example of the influence of excavation on the existing shield tunnel is investigated, and the characteristics of transverse and longitudinal deformation of shield tunnel are analyzed. The method of calculating longitudinal deformation of shield tunnel based on Mindlin solution and Winkler foundation beam theory is summarized. 2) based on finite element method, the influence of excavation process on lateral shield tunnel is simulated, and the deformation and stress change of supporting structure and transverse deformation of tunnel are analyzed emphatically. Longitudinal deformation characteristics and mechanical changes. This paper analyzes the influence factors of the deformation of shield tunnel in lateral subway, and studies the horizontal net distance of foundation pit, the change of buried depth of shield tunnel, the excavation depth of foundation pit, and the stiffness of foundation pit support system. The change of orientation and size of foundation pit and the influence of reverse construction; The influence of different factors on the deformation of side shield tunnel under excavation unloading is studied. (4) the flow of determining the deformation control value of tunnel lateral foundation pit is put forward, and the corresponding deformation control value of foundation pit under certain conditions (horizontal net distance, buried depth, etc.) is calculated on the basis of an example in this paper. Finally. This paper summarizes and analyzes the deformation control measures and engineering application of the side foundation pit of shield tunnel.
【学位授予单位】：华南理工大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U455.43;U231.3

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