基坑开挖对既有地铁隧道的变形影响研究

发布时间：2018-03-19 02:31

本文选题：深基坑　切入点：既有隧道　出处：《中国地质大学(北京)》2015年硕士论文　论文类型：学位论文

【摘要】：随着我国城市化进程的发展,地下空间的开发与利用越来越受到重视,由此产生的大量位于城市繁华地段的基坑工程。而城市基坑工程周围往往存在通信线路、地下水管线、地铁隧道等其他市政设施,施工环境非常复杂。这类基坑的开挖不仅涉及到基坑本身的安全与稳定,同时还可能对临近的建筑物、构筑物造成影响。地铁隧道有严格的变形限制,而基坑开挖势必造成周围土体的变形,如果施工不当,则会影响邻近地铁隧道的运行甚至造成安全问题。本文以理论分析为指导,采用数值模拟的方法,对基坑开挖引起邻近既有隧道的变形问题做了分析,主要内容及成果如下:1、介绍了基坑开挖对临近隧道变形的研究现状,总结了基坑与隧道变形的理论、影响因素以及相关的理论计算方法。2、运用单一变量法,保持基坑与隧道的竖向相位置不变,改变水平相对位置,用FLAC3D软件进行基坑开挖全过程的模拟与分析,研究了隧道水平、竖向变形与两者水平位置的关系。结果表明:随着隧道与基坑相对距离的减小,隧道的水平变形和竖向变形逐渐增大;在本文工程的地质条件下,2m位置为隧道变形临界位置,若小于该值,则隧道的变形不满足规范要求,需要采取特殊施工方法或是对基坑及隧道进行加固处理。3、运用单一变量法,保持基坑与隧道的水平相对位置不变,分别在基坑位于隧道侧方与正下方时,改变两者的竖向相对位置,用FLAC3D进行了模拟与分析,研究了隧道水平、竖向变形与两者竖向位置的关系。结果表明:随着两者相对距离的减小,隧道的水平变形和竖向变形均逐渐增大,且水平变形小于竖向变形;隧道位于基坑正下方时,由于土体隆起导致隧道的竖向变形较大;本文工程中4m位置为临界位置;当相对距离大于10m时,基坑开挖对隧道的变形影响很小。
[Abstract]:With the development of urbanization in China, more and more attention has been paid to the development and utilization of underground space. Other municipal facilities, such as subway tunnels, are constructed in a very complex environment. Such excavation involves not only the safety and stability of the foundation pit itself, but also the adjacent buildings. The subway tunnel has strict deformation limit, and the excavation of foundation pit is bound to cause the deformation of surrounding soil, if the construction is not proper, Based on the theoretical analysis and numerical simulation method, the deformation of adjacent existing tunnels caused by foundation pit excavation is analyzed. The main contents and results are as follows: 1. This paper introduces the research status of the deformation of the adjacent tunnel in foundation pit excavation, summarizes the theory of foundation pit and tunnel deformation, the influencing factors and the related theoretical calculation method .2. the single variable method is used. In order to keep the vertical phase position of foundation pit and tunnel unchanged and change the relative position of level, the whole excavation process of foundation pit is simulated and analyzed by FLAC3D software, and the tunnel level is studied. The results show that with the decrease of the relative distance between the tunnel and the foundation pit, the horizontal and vertical deformation of the tunnel increases gradually, and the 2 m position is the critical position of the tunnel deformation under the geological conditions in this paper. If the value is less than this value, the deformation of the tunnel does not meet the requirements of the code, so it is necessary to adopt special construction methods or reinforce the foundation pit and tunnel. The single variable method is used to keep the horizontal position of the foundation pit and tunnel unchanged. When the foundation pit is located on the side and directly below the tunnel, the vertical relative position of the two is changed, and the tunnel level is studied and simulated by FLAC3D. The results show that with the decrease of the relative distance between them, the horizontal and vertical deformation of the tunnel increases gradually, and the horizontal deformation is smaller than the vertical deformation, and the tunnel is located directly below the foundation pit. The vertical deformation of the tunnel caused by the uplift of the soil mass is larger; the critical position is 4m in this paper; when the relative distance is more than 10m, the excavation of foundation pit has little effect on the deformation of the tunnel.
【学位授予单位】：中国地质大学(北京)
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U231;U456.3;TU753

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