基坑开挖影响既有临近隧道变形与稳定性研究

发布时间：2018-02-28 08:27

本文关键词： 基坑开挖既有隧道变形特征有限元分析影响范围　出处：《西安科技大学》2017年硕士论文　论文类型：学位论文

【摘要】：随着国家经济的快速发展,地下管线、线路以及构筑物的增多,基坑开挖临近既有运营隧道的现象逐渐成为常态化,基坑工程施工使得周边土体发生变形,结构形式的不同以及两者之间距离的变化都会在不同程度上影响相邻隧道的稳定性,既有地铁隧道周边土体附加应力逐渐升高,使其产生不同程度的位偏移。隧道结构稳定性的破坏可能会对公共财产安全造成重大损失。是以对于基坑开挖影响既有隧道的情况应加以研究,制定合理安全的控制措施。文章通过有限元数值模拟软件MIDAS/GTS建立数据模型,基于临近郑州既有地铁地上工程的基坑开挖及其监测数据,模拟了基坑开挖在不同深度及不同水平位置对临近结构的影响,同时提出了相应的控制以及保护措施。参考国内及海外学者的学术成果,分析了不同条件下基坑工程施工所产生的影响及临近结构的变形特性。将两者之间的不同位置关系、控制土体变形的方案、工程施工顺序、排水措施等进行归纳分类。基于郑州地铁相邻建筑施工工程,利用有限元数值模拟软件建立工程模型,考虑整个工程的初始应力分析,得出临近隧道的变形曲线以及基坑开挖的影响范围与深度,从而提出保证地铁构造安全性的合理措施。通过所建立的工程数据模型,采用单一变量法,改变基坑与结构的相对位置关系以及相应的施工条件,分别模拟了两者之间的水平位置、正下方位置以及侧方向的位置等情况变化下,原有结构的偏移量以及所受到的不同应力。对基坑开挖临近既有隧道的保护方案进行比选与设计,通过不同施工措施和方案控制基坑变形与周边土体沉降,提出保证结构正常运行的合理施工方案。
[Abstract]:With the rapid development of the national economy, the increase of underground pipelines, lines and structures, the excavation near the existing tunnel phenomenon has become the norm, the construction of foundation pit engineering makes the surrounding soil deformation and stability between the different structural forms and their changes will affect the distance of the adjacent tunnel in different degrees, both there are additional stress of soil around the subway tunnel gradually increased, offset to produce different degrees. The structure stability of tunnel damage may cause heavy losses to public property. Based on the existing tunnel excavation influence situation should be studied, reasonable control measures of safety. The software MIDAS/GTS to establish data model through the finite element numerical simulation, near the Zhengzhou Metro ground engineering excavation and monitoring data based on simulated excavation in different Effect of different depth and the horizontal position of the adjacent structure, and put forward the corresponding control and protection measures. The reference of domestic and overseas scholars of academic achievements, analyzed the deformation characteristics of the impact of the foundation pit engineering construction under different conditions and different position of adjacent structures. The relationship between the two, the soil deformation control scheme, engineering the construction sequence, and drainage measures are summarized. The Zhengzhou Metro adjacent construction project based on the finite element numerical simulation software engineering model was established, considering the initial engineering stress analysis, the deformation curve near the tunnel and the excavation influence scope and depth, so as to put forward reasonable measures to ensure the safety of subway construction. According to the engineering data model is established by using a single variable method, changing the relative position between the foundation and structure and the corresponding construction conditions, The horizontal position between the two are simulated, such as location changes just below the position and side direction, the offset of the original structure and the different stress. To protect the scheme of foundation pit excavation near the existing tunnel is selected and designed, through different construction measures and schemes to control the deformation of foundation pit and the surrounding soil settlement, reasonable construction scheme is proposed to guarantee the normal operation of the structure.

【学位授予单位】：西安科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：U451

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