某新建地铁隧道近接下穿既有线车站力学响应分析及沉降模拟研究

发布时间：2018-06-24 22:44

本文选题：地铁隧道 + 车站　；参考：《兰州交通大学》2015年硕士论文

【摘要】：随着我国城市地下空间开发利用的广泛兴起,特别是城市地铁隧道规划建设的快速推进,不可避免的会遇到越来越复杂的近接工程问题。为了确保近接工程的顺利进行,就必须保证邻近既有建(构)筑物的结构安全及正常使用功能;那么在施工过程中采取何种施工技术及辅助工法,以及在设计施工中如何有效预测和避免沉降、塌陷的发生,使对既有建(构)筑物及地下管线的影响降到最低,并确保施工安全,同时实现较高的经济效益,是目前急需研究解决的问题。本文以深圳市地铁7号线密贴下穿既有4号线车站工程为背景,采取理论研究、有限元数值分析及基于数值模拟分析沉降监测等方法,利用ADINA有限元分析软件建立计算模型,对全断面注浆加固和CRD平顶直墙暗挖下穿既有线车站施工方案进行了模拟研究。通过分析量化了施工过程中存在的各类风险要点,为工程的顺利实施以及类似工程开展提供理论依据和合理的预测分析。论文主要工作内容如下:1.针对论文选题中的实际工程仍处于施工初期阶段,且缺乏实测资料等情况,本文重点对工程近接下穿施工方案、工程难点及相关要素进行了理论评估和预测分析,制定了相应的对策措施,并结合现场工程地质勘查资料,利用工程类比方法确定各类材料参数,通过ADINA有限元软件模拟计算证明取值是合理的。2.在大量查阅关于沉降机理的相关数值解析方法理论及研究成果的基础上,并充分考虑了加固区相关参数的选取及对应措施,通过数值模拟方法进行了近接下穿开挖施工对既有线隧道的各类响应分析。3.按照Peck经验公式及相关理论,得知隧道开挖引起的横向地层沉降规律,即横向沉降槽曲线可以用正态分布曲线来表示;纵向地表沉降会随着隧道的开挖掘进逐渐趋于稳定,该理论可作为模拟检测数据的合理性判据。4.通过有限元分析软件ADINA对论文中近接下穿工程CRD开挖施工方案进行了模拟分析,按照施工方案明确的开挖顺序进行了施工步序的生死单元定义,通过不同的开挖步,对开挖引起的既有线车站结构沉降变形及安全运营等影响因素进行了分析预测,模拟计算得知既有线车站地板最大竖向变形为0.45mm小于控制值,而且初衬顶板最大收敛值为0.80mm小于控制值,均满足精度要求,同时发现计算值存在偏小的问题,应存在一定误差,但从模拟结果来看总的响应规律是比较符合理论实际的。
[Abstract]:With the development and utilization of urban underground space in China, especially the rapid development of urban subway tunnel planning and construction, it is inevitable to meet more and more complex problems of proximity engineering. In order to ensure the smooth progress of the adjacent construction, it is necessary to ensure the structural safety and normal use function of the adjacent existing buildings, and then what construction techniques and auxiliary methods should be adopted in the construction process, And how to effectively predict and avoid settlement and collapse in design and construction, so as to minimize the influence on existing buildings and underground pipelines, and to ensure the safety of construction, and to achieve higher economic benefits. At present, it is urgent to study and solve the problem. In this paper, based on the project of Shenzhen Metro Line 7, the method of theoretical research, finite element numerical analysis and settlement monitoring based on numerical simulation is adopted to establish the calculation model by using Adina finite element analysis software. The construction scheme of full section grouting reinforcement and CRD flat roof straight wall tunneling through existing railway station is simulated and studied. By analyzing and quantifying all kinds of risk points in the construction process, this paper provides theoretical basis and reasonable forecast analysis for the smooth implementation of the project and the development of similar projects. The main contents of the thesis are as follows: 1: 1. In view of the fact that the actual project is still in the initial stage of construction, and lack of the measured data, this paper focuses on the theoretical evaluation and prediction of the construction scheme, engineering difficulties and related elements of the project. The corresponding countermeasures and measures are worked out, combined with the field engineering geological survey data, various material parameters are determined by using the engineering analogy method, and the value is proved to be reasonable by using Adina finite element software simulation calculation. On the basis of a large number of related numerical analytical methods and research results on settlement mechanism, the selection of relevant parameters and corresponding measures in the reinforcement area are fully considered. Through numerical simulation method, various kinds of response analysis of the tunnel under the close connection are carried out. 3. According to Peck empirical formula and related theory, it is known that the law of lateral ground settlement caused by tunnel excavation, that is, the curve of transverse settlement trough can be expressed by normal distribution curve, and the longitudinal surface settlement will gradually become stable with the excavation of tunnel. This theory can be used as the rationality criterion of simulated test data. Through the finite element analysis software Adina, the paper simulates and analyzes the construction scheme of CRD excavation in the near connection project, defines the birth and death unit of the construction step according to the definite excavation sequence of the construction plan, and through different excavation steps. The influence factors such as settlement deformation and safe operation of the existing railway station structure caused by excavation are analyzed and forecasted. The simulation results show that the maximum vertical deformation of the existing railway station floor is less than the control value of 0.45mm. Moreover, the maximum convergence value of the initial liner is smaller than the control value, which satisfies the precision requirement. At the same time, it is found that the calculation value is small, and there should be some errors. But from the simulation results, the overall response law is more in line with the theory and practice.
【学位授予单位】：兰州交通大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U231.3;U455.4

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