大断面黄土隧道开挖变形监测研究及施工过程分析

发布时间：2018-05-04 06:59

本文选题：黄土隧道 + 监测数据　；参考：《兰州交通大学》2017年硕士论文

【摘要】：近年因为来国家各类方针政策的施行,西部各省份交通运输行业得到迅速发展,越来越多的公路、铁路将穿越黄土区域。我国黄土隧道设计和施工并没有系统的理论体系,大多数都是以工程类比法为主。本文以塘家塬黄土隧道为依托,主要采用现场监测量控、围岩压力理论计算及数值模拟计算三种方法相结合的手段,研究黄土隧道围岩变化规律和应力分布规律,为以后的黄土隧道工程进行指导和借鉴。主要研究内容如下:⑴.介绍了黄土隧道的四种施工工法,分别为:中隔壁开挖法(CD法)、双侧壁导坑法、交叉中隔壁法(CRD法)及三台阶法。对比分析四种工法,评价其优劣性。⑵.根据现场实测数据得出:黄土隧道围岩变形一般经历三个阶段“急剧变化—缓慢变化—基本稳定”。仰拱封闭以前变形量约占总变形量90%以上,所以基本稳定阶段一般发生在仰拱施作完成后。根据《公路隧道施工技术规范》规定得出:二次衬砌施作的最佳时间为隧道开挖后的第18天。⑶.采用现有的六种围岩压力计算方法和七种隧道深浅埋判断法计算得出,泰沙基理论计算结果和实测结果能很好的吻合,推荐使用泰沙基理论为塘家塬大断面黄土隧道的围岩计算理论,建议采用47m为塘家塬黄土隧道的深浅埋分界标准。⑷.通过数值模拟研究在同样的支护设计参数下,中隔壁开挖法(CD法),双侧壁导坑法及三台阶法的围岩变形规律、应力分布规律及塑性区分布规律,得出结论如下:双侧壁导坑法对于大断面黄土隧道的开挖稳定性以及安全性有较好的保障,能够更有效地控制围岩变形,建议在围岩较差段采用双侧壁导坑法。
[Abstract]:In recent years, due to the implementation of various national policies, the transportation industry in the western provinces has developed rapidly, and more and more roads and railways will pass through the loess region. There is no systematic theoretical system in the design and construction of loess tunnel in China, most of which are based on engineering analogy. Based on the Tangjiayuan Loess Tunnel, this paper studies the variation law and stress distribution law of the surrounding rock of the loess tunnel by means of the combination of three methods: field monitoring and control, theoretical calculation of surrounding rock pressure and numerical simulation calculation. For the future loess tunnel engineering guidance and reference. The main research contents are as follows: 1. This paper introduces four construction methods of loess tunnel, which are: middle next door excavation method, double side wall guide pit method, cross middle next door method and CRD method, and three stage method. Compare and analyze the four methods and evaluate their merits and demerits. 2. According to the field measured data, it is concluded that the deformation of surrounding rock in loess tunnel generally goes through three stages: rapid change, slow change and basic stability. The deformation amount of the inverted arch is about 90% of the total deformation before closure, so the basic stable stage usually occurs after the completion of the inverted arch construction. According to "Technical Specification for Highway Tunnel Construction", it is concluded that the best time for secondary lining construction is the 18th day after tunnel excavation. By using the existing six kinds of surrounding rock pressure calculation methods and seven tunnel depth and shallow burying judgment methods, it is concluded that the calculated results of Teshaji theory are in good agreement with the measured results. It is recommended to use the theory of Taishaji as the calculation theory of surrounding rock of large section loess tunnel in Tangjiayuan, and to adopt 47m as the standard of deep and shallow buried boundary of Tangjiayuan loess tunnel. Under the same supporting design parameters, the deformation law, stress distribution law and plastic zone distribution law of surrounding rock in the middle adjacent excavation method, double side wall guide pit method and three step method are studied by numerical simulation. The conclusion is as follows: the method of double-side wall guide pit has a good guarantee for the stability and safety of large section loess tunnel excavation and can control the deformation of surrounding rock more effectively. It is suggested that the double-side wall tunnel method should be used in the poor section of surrounding rock.
【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】：U456.3

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