北京市某基坑开挖对邻近地铁隧道的影响分析

发布时间：2018-04-11 09:44

本文选题：基坑开挖 + 隧道变形　；参考：《河北工程大学》2017年硕士论文

【摘要】：基坑工程对周边环境影响较大,主要是会造成邻近建筑物、道路、管线等位移、变形甚至破坏。当基坑工程邻近既有地铁隧道时,更需要采取相应措施严格控制基坑支护结构和周围土体的变形量,降低隧道所受影响,确保地铁的安全运行。本文以北京市某邻近地铁隧道的基坑工程为例,通过数值模拟的方法研究分析了基坑开挖支护过程对邻近隧道的变形影响。主要内容和结论如下:(1)介绍了基坑支护结构变形、坑底隆起及地表沉降等基坑变形机理,以及变形的相关理论与计算方法。从基坑围护桩墙施工、基坑降水、基坑开挖等方面分析了基坑工程引起隧道变形的潜在原因,并且介绍了基坑开挖引起隧道变形的计算理论与方法。(2)使用理正深基坑软件对基坑支护方案进行设计、计算,并且验算了相关基坑稳定性安全系数与变形量,验证支护方案的安全性;然后使用FLAC3D软件对邻近地铁隧道的基坑剖面建立数值模型,模拟分析了施工过程中基坑的变形情况以及对邻近隧道的变形影响。(3)对比理正深基坑软件、FLAC3D软件与现场监测得到的基坑侧壁水平位移、地表沉降、坑底隆起等数据,分析了三者的差异,验证了所建模型的正确性。(4)经模拟计算得到,基坑开挖引起邻近隧道向基坑方向进行水平位移,最大水平位移量为3.31mm,同时造成隧道向地表方向上浮位移,最大竖向位移量为3.58mm,隧道位移量满足地铁安全运行的设计要求。本文的研究对类似工程的设计分析具有一定参考价值。
[Abstract]:Foundation pit works have a great impact on the surrounding environment, mainly resulting in the displacement, deformation and even destruction of adjacent buildings, roads, pipelines and so on.When the foundation pit works near the existing subway tunnel, it is more necessary to take corresponding measures to strictly control the deformation of the foundation pit supporting structure and surrounding soil, reduce the influence on the tunnel and ensure the safe operation of the subway.Taking the foundation pit engineering of a subway tunnel in Beijing as an example, the influence of excavation support process on the deformation of adjacent tunnel is studied by numerical simulation.The main contents and conclusions are as follows: (1) the deformation mechanism of foundation pit, such as foundation pit supporting structure deformation, pit bottom uplift and ground subsidence, as well as the relevant theory and calculation method of foundation pit deformation are introduced.The potential causes of tunnel deformation caused by foundation pit engineering are analyzed from the aspects of foundation pit retaining pile wall construction, foundation pit dewatering, foundation pit excavation and so on.This paper also introduces the calculation theory and method of tunnel deformation caused by foundation pit excavation. (2) the foundation pit support scheme is designed and calculated by using Lizheng deep foundation pit software, and the safety factor and deformation amount of foundation pit stability are checked and calculated.The security of the supporting scheme is verified, and then the numerical model of the foundation pit profile of the adjacent subway tunnel is established by using FLAC3D software.The deformation of foundation pit during construction and the influence of deformation on adjacent tunnel are simulated and analyzed.The differences among the three models are analyzed, and the correctness of the model is verified. The simulation results show that the excavation of foundation pit results in the horizontal displacement of the adjacent tunnel towards the foundation pit, and the maximum horizontal displacement is 3.31 mm, which results in the upward displacement of the tunnel towards the ground.The maximum vertical displacement is 3.58 mm, and the tunnel displacement can meet the design requirements of subway safe operation.The research in this paper has certain reference value for the design analysis of similar engineering.
【学位授予单位】：河北工程大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：U456.3;U231;TU753

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