兰州地铁饱和黄土大跨区间隧道施工数值模拟研究

发布时间：2018-06-08 21:24

本文选题：浅埋暗挖 + 饱和黄土　；参考：《兰州交通大学》2017年硕士论文

【摘要】：在我国各大城市高速建设的同时,交通拥堵、城市交通基础设施建设滞后、城市交通抗灾害能力不足等问题也逐渐显现出来,并对城市的进一步发展起到了反作用。城市轨道交通系统是缓解大城市交通拥堵状况、改善城市生态环境、保证城市发展持续稳定的最优方式之一,具有绿色、节能、环保、快捷等特点,符合可持续发展的原则。同我国其他各大城市一样,兰州市也面临着类似的问题,因此希望通过建设兰州地铁工程来解决。作为在西部地区黄土地层修建、兰州市的第一条地铁工程,其面临着一系列问题。本文以兰州地铁一号线一期TJⅢ-16工区东岗站后配线段的大跨区间隧道为依托工程,针对兰州地区饱和黄土地层中大跨区间隧道的施工过程中围岩变形进行研究。在本文中,以三维仿真数值模拟为手段,对比研究在考虑流固耦合效应和不考虑流固耦合效应两种情况下,饱和黄土围岩的应力场、地表沉降、拱部下沉、周边收敛、支护结构受力的变化情况。根据本文研究项目施工现场的施工设计参数、围岩地质条件、实际施工措施,分别建立CRD法、双侧壁导坑法模型对开挖支护阶段进行了全过程分析,并以双侧壁导坑法为基础,在考虑流固耦合的条件下,通过对双侧壁导坑法的施工进行优化,以期找到最优的施工方法。本文主要的研究成果有:(1)通过对比分析可知,基于流固耦合计算模式求解得到的结果,与不考虑耦合效应时两者的结果有较大差异。因此,对于饱和黄土的模拟,应考虑土中水的作用,否则将对结果造成较大影响;(2)对比CRD法与双侧壁导坑法的分析结果,在饱和黄土隧道中,同等条件下六部CRD对于地表沉降、围岩变形的控制效果要优于双侧壁导坑法。通过喷射混凝土封闭掌子面后,双侧壁导坑法对于围岩土体变形的控制效果略优于六部CRD法;(3)通过对比双侧壁导坑法的不同优化结果,双侧壁导坑法预留核心土相对于其他情况,对于控制地表沉降、拱部下沉效果最好;当核心土的长度为1m时,控制变形相对而言最好。综上所述,文章以实际工程为依托对象,对浅埋大跨度饱和黄土区间隧道进行了数值模拟分析,对施工方法提出合理性建议,可以为后续地铁浅埋暗挖隧道施工提供参考和指导。
[Abstract]:At the same time, the traffic congestion, the lagged construction of urban traffic infrastructure and the insufficient ability of urban traffic to resist disasters have gradually appeared in the high-speed construction of major cities in China, and have played a counterproductive role in the further development of cities. Urban rail transit system is one of the best ways to alleviate traffic congestion, improve urban ecological environment and ensure sustainable and stable urban development. It has the characteristics of green, energy saving, environmental protection, quick and so on, and conforms to the principle of sustainable development. Like other major cities in China, Lanzhou is faced with similar problems, so it is hoped to solve the problem through the construction of Lanzhou Metro Project. As the first subway project in Lanzhou, which is built in the west of China, it faces a series of problems. Based on the large-span inter-area tunnel in the rear distribution section of Donggang Station in the first phase of Lanzhou Metro Line 1, this paper studies the deformation of surrounding rock in the construction process of the large-span inter-zone tunnel in saturated loess layer in Lanzhou area. In this paper, the stress field, ground subsidence, arch subsidence and circumference convergence of saturated loess surrounding rock are studied by means of three-dimensional simulation numerical simulation, considering the fluid-solid coupling effect and the fluid-solid coupling effect. The change of the force on the supporting structure. According to the construction design parameters, surrounding rock geological conditions and actual construction measures of the construction site of the project, the CRD method and the double-side wall guide pit method model are established respectively to analyze the whole process of excavation support stage, and based on the double-side wall guide pit method. Under the condition of fluid-solid coupling, the construction of double-sidewall guide pit method is optimized in order to find the best construction method. The main research results in this paper are as follows: (1) by comparison and analysis, we can see that the results obtained based on the fluid-solid coupling model are quite different from those obtained without considering the coupling effect. Therefore, for the simulation of saturated loess, the effect of water in soil should be considered, otherwise it will have a great influence on the results. Compared with the analysis results of CRD method and double-sidewall guide pit method, in the saturated loess tunnel, the six CRDs are used for ground subsidence under the same conditions. The control effect of surrounding rock deformation is better than that of double side wall guide pit method. After spraying concrete closed face, the control effect of double-side wall guide pit method on the deformation of surrounding rock soil is slightly better than that of six-part CRD method / 3) by comparing the different optimization results of double-side wall guide pit method. Compared with other conditions, the method of double side wall guide pit reserving core soil has the best effect on controlling surface subsidence, and when the length of core soil is 1 m, the control deformation is the best. To sum up, based on the actual project, the paper carries out numerical simulation analysis on the shallow buried large-span saturated loess section tunnel, and puts forward some reasonable suggestions to the construction method. It can provide reference and guidance for the construction of shallow-buried underground tunnel.
【学位授予单位】：兰州交通大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：U455.4

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