强风化页岩浅埋偏压隧道支护措施的优化与数值分析研究

发布时间：2018-02-02 08:56

本文关键词： 强风化页岩浅埋偏压支护结构优化 FLAC3D　出处：《江西理工大学》2015年硕士论文　论文类型：学位论文

【摘要】：近年来,高速公路逐年增多,它穿山越岭、行河跨湖,线路追求顺直、平缓,为了满足这些要求,使得行车更加方便,我们常常会用到隧道方案。浅埋偏压隧道是隧道工程中较常存在的一种形式,多出现在线路与地形等高线平行的地方,尤其在山岭河畔边,此时的地质环境一般比较差,围岩强度低,稳定性差,岩层节理裂隙较发育,还存在有一定程度的地表渗水。本文以龙山至永顺高速公路工程中的砂子坡隧道为依托工程,对隧道地处强风化页岩的洞口浅埋偏压段的支护结构进行优化设计和数值模拟分析,主要包括:(1)根据砂子坡隧道相关地质勘察报告和风险评估报告,阐述砂子坡隧道所处的地质地貌环境和软弱围岩区段,表明合理运用支护结构体系保障施工安全顺利的重要性,且在整体支护体系初步设计中选取相应的支护形式和支护参数对隧道进行支护。(2)收集概括不同支护结构在隧道围岩中的作用机理,分别概述超前支护、初期支护、二次衬砌在围岩中的支护效果并以此为基础对洞口段的支护做优化设计。(3)采用FLAC3D有限差分软件对强风化页岩洞口浅埋偏压段进行数值模拟验算,分别从围岩的应力场、位移场,支护结构的受力特点进行分析,并对比分析了天然状态和降雨状态隧道无支护措施的稳定性情况;全断面开挖法和CRD开挖法隧道支护措施的适用性情况。最后进行总结,所选用的支护措施在两种开挖方法中都有良好的适用性,能满足保证隧道稳定的要求。
[Abstract]:In recent years, the highway has increased year by year, it is crossing mountains, running rivers across lakes, the lines pursue smooth, smooth, in order to meet these requirements, make driving more convenient. We often use the tunnel scheme. Shallow buried bias tunnel is a more common form in tunnel engineering. It often appears in parallel with the terrain contour line, especially at the edge of the mountain and river. At this time, the geological environment is generally poor, the strength of surrounding rock is low, the stability is poor, and the fracture of rock layer is relatively developed. There is also a certain degree of surface seepage. This paper relies on the sand slope tunnel in the Longshan-Yongshun Expressway project. The optimum design and numerical simulation analysis of the support structure of the tunnel located at the shallow burying partial pressure section of the mouth of the strongly weathered shale are carried out, which mainly include: 1) according to the relevant geological investigation report and the risk assessment report of the sand slope tunnel. The geological and geomorphological environment and soft surrounding rock section of the sand slope tunnel are expounded, which indicates the importance of using the support structure system reasonably to ensure the construction safety and smooth. And in the preliminary design of the overall support system, select the corresponding support form and support parameters to support the tunnel.) collect and summarize the mechanism of different supporting structure in the surrounding rock of tunnel, and summarize the advance support respectively. Initial support. The supporting effect of secondary lining in surrounding rock and the optimum design of tunnel opening section based on it. The FLAC3D finite difference software is used to simulate and calculate the shallow buried bias section at the mouth of strongly weathered shale. The characteristics of stress field, displacement field and supporting structure of surrounding rock are analyzed respectively, and the stability of tunnel without supporting measures in natural state and rainfall state is compared and analyzed. The applicability of the full section excavation method and CRD excavation method tunnel support measures. Finally, the selection of supporting measures in the two excavation methods have good applicability. It can satisfy the requirement of tunnel stability.
【学位授予单位】：江西理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U455.7

【引证文献】