公路软岩隧道小型拱形塌方腔体稳定性及处治措施研究

发布时间：2018-06-02 10:05

本文选题：隧道工程 + 塌方　；参考：《长安大学》2014年硕士论文

【摘要】：塌方是隧道施工中最常见的灾害现象之一。目前，隧道塌方问题的研究主要集中于原因分析及处治措施，对塌方腔体周边围岩稳定性尚未有系统的分析。一般情况下，，隧道塌方处治主要针对大、中型塌方事故，对小型塌方受关注较少，但工程实践中，大部分的大、中型塌方都是小型塌方没能得到及时治理而造成的；同时隧道塌方事故中小型塌方所占的比例较大。因此，开展小型塌方腔体周边围岩稳定性与处治措施研究对保障施工安全具有着重要的指导性意义。本文基于软弱围岩隧道塌方的特点，采用统计分析、理论分析与数值模拟相结合的方法，对自重应力场作用下公路隧道塌方腔体周边围岩稳定性及处治措施进行深入的研究。论文主要工作如下： 1.对无支护条件下与有支护条件下隧道塌方事故进行了分类统计，统计分析的内容主要有塌方腔体形状、位置、时间节点、原因以及塌方处治方法。 2.基于统计分析，对无支护条件下隧道拱形塌方进行了数值模拟，分析了塌方腔体周边围岩的位移场、应力场以及围岩塑性区。 3.基于统计分析，对有支护条件下隧道拱形塌方进行了数值模拟，分析了塌方腔体周边围岩的位移场、应力场、围岩塑性区以及支护结构受力特征。 4.在无支护条件下与有支护条件下隧道拱形塌方数值模拟分析结果的基础上，分别依据塌方腔体周边围岩塑性区位置或应力松弛最严重部位，对两种条件下的隧道塌方提出了处治方案，进行了数值模拟分析，得到了不同施工阶段下隧道各个部位的位移变化规律、围岩塑性区变化情况、以及支护结构受力特征，并进行了对比分析，对处治方案的处治效果作出评价。
[Abstract]:Collapse is one of the most common disasters in tunnel construction. At present, the study of tunnel collapse mainly focuses on the cause analysis and treatment measures, and there is no systematic analysis on the stability of surrounding rock around the cavern. Generally speaking, the treatment of tunnel collapse is mainly aimed at the large and medium collapse accidents, and less attention is paid to the small collapse, but in engineering practice, most of the large and medium-sized landslides are caused by the failure to get timely treatment of the small landslides. At the same time, the proportion of small and medium-sized landslides in tunnel collapse accidents is larger. Therefore, the research on surrounding rock stability and treatment measures of small cave-in cavity is of important guiding significance to ensure construction safety. Based on the characteristics of soft surrounding rock tunnel collapse, the stability and treatment measures of surrounding rock surrounding tunnel cave-in cavity of highway tunnel under the action of self-gravity stress field are studied in this paper by means of statistical analysis, theoretical analysis and numerical simulation. The main work of the thesis is as follows: 1. In this paper, the tunnel collapse accidents without and with support are classified and counted. The main contents of statistical analysis are the shape, position, time node, cause and treatment method of collapse cavity. 2. Based on statistical analysis, the numerical simulation of tunnel arch collapse is carried out under the condition of no support, and the displacement field, stress field and plastic zone of surrounding rock around cave-in cavity are analyzed. 3. Based on the statistical analysis, the numerical simulation of tunnel arch collapse under the condition of supporting is carried out, and the displacement field, stress field, plastic zone of surrounding rock and the mechanical characteristics of supporting structure are analyzed. 4. On the basis of the numerical simulation results of tunnel arch collapse under the condition of no support and with support, the plastic zone around the cavern or the most serious part of stress relaxation are obtained, respectively. The treatment scheme of tunnel collapse under two kinds of conditions is put forward and the numerical simulation analysis is carried out. The displacement variation law, the plastic zone change of surrounding rock and the mechanical characteristics of supporting structure are obtained under different construction stages. A comparative analysis was made to evaluate the effect of the treatment scheme.
【学位授予单位】：长安大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U459.2;U457

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