黄土隧道一次模筑混凝土衬砌的预支护及综合施工技术研究

发布时间：2018-10-15 16:49

【摘要】：黄土是一种具有独特工程特性的土,因此黄土隧道的施工面临许多重要的问题,其中很多隧道在洞口或者洞身段围岩软弱,大多数隧道开挖时掌子面周围的岩体自稳能力很差,需要对其进行预加固即超前支护,而注浆小导管作为众多超前支护中施工工艺简单、加固效果明显、经济性强的方法之一在工程实践中得到越来越多的应用;同时为了能更有效、安全、快速的施工,应对预支护和综合施工技术进行了研究。本文以“连霍高速”的定远2#隧道为依托,以黄土隧道V级围岩段的工程施工为分析要点,对以上两个问题进行研究。论文的完成的主要工作如下:(1)通过定远隧道现场监控量测数据分析围岩的变形情况以及支护受力的特点。系统分析两者之间的变化关系,分析结果表明,围岩变形持续时间长、初期变形速率快。(2)对超前小导管的注浆加固机理及作用效应进行系统分析,然后对超前小导管预支护的各项参数进行一个简单论述,用MIDAS/GTS软件进行数值计算模拟,分析注浆小导管管径、环向间距、管长和注浆长度等因素对加固效果的影响。(3)有针对性的提出了不同的变形控制措施,通过模拟计算对二台阶环形开挖预留核心土的工法在不同台阶高度、台阶长度以及开挖进尺的情况下进行逐个分析。并最终优选最适合的控制措施来抑制围岩的变形。(4)对比分析采用不同开挖形式,人工费和油耗费在总支出上所占比重最大。油耗费是随机械化的程度改变的,使用的机械设备越多机械化水平越高油耗的费用也随之增大。但相比昂贵的人工费,总支出会降低。所以在选择设备时应尽量选取工作利用率高的配套机械。
[Abstract]:Loess is a kind of soil with special engineering characteristics, so the construction of loess tunnel is faced with many important problems, many of which are weak in the surrounding rock at the entrance or section of the hole, and the rock mass around the face of most tunnels is poor in self-stability when excavating. It needs to be pre-strengthened, that is, advance support, and grouting small pipe as a large number of lead support construction technology is simple, the reinforcement effect is obvious, one of the strong economic methods in engineering practice has been more and more applied; At the same time, in order to be more effective, safe and rapid construction, we should study the pre-support and comprehensive construction technology. Based on the Dingyuan2# tunnel of "Lianghuo high speed" and the engineering construction of V-class surrounding rock section of loess tunnel, the above two problems are studied in this paper. The main work of this paper is as follows: (1) the deformation of surrounding rock and the characteristics of supporting force are analyzed by monitoring and measuring data of Dingyuan tunnel. The results show that the deformation duration of surrounding rock is long and the initial deformation rate is fast. (2) the mechanism of grouting reinforcement and the effect of grouting on small lead ducts are systematically analyzed. Then, the parameters of pre-support for leading small ducts are simply discussed, and the numerical calculation and simulation are carried out with MIDAS/GTS software, and the diameter and circumferential spacing of grouting small ducts are analyzed. The influence of pipe length and grouting length on reinforcement effect. (3) different deformation control measures are put forward. The step length and the excavation advance are analyzed one by one. Finally, the most suitable control measures are selected to restrain the deformation of surrounding rock. (4) by comparing and analyzing the different excavation forms, the labor cost and fuel consumption cost account for the largest proportion in the total expenditure. The cost of oil consumption varies with the degree of mechanization, and the higher the level of mechanization, the higher the cost of oil consumption. But compared with expensive labor costs, total spending will be reduced. Therefore, the selection of equipment should be as high as possible to select the working efficiency of the supporting machinery.
【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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