强渗流条件下山岭分离式隧道围岩变形分析

发布时间：2018-01-08 17:38

本文关键词：强渗流条件下山岭分离式隧道围岩变形分析　出处：《湘潭大学》2015年硕士论文　论文类型：学位论文

【摘要】：随着我国交通工程建设的不断发展完善,高速公路的建设逐渐从人口密度较大的平原地区向山岭重丘区开始延伸,而山岭隧道的建设越来越突显其重要性,并且在整个隧道工程建设中所占的比重越来越高。在山岭隧道修建工程中,山区条件的复杂性导致了岩(土)体结构条件与地质条件的多样性,使隧道施工过程中经常会出现拱顶塌方事故或大变形失稳等问题,这大大增加了资金投入与施工难度。目前,针对山岭隧道围岩变形的研究主要着重于围岩力学参数的降低对隧道施工产生的不利影响及相应施工控制措施,而对隧道围岩内部地下水渗流的力学影响,特别是针对强渗流条件下山岭隧道围岩变形分析的研究还不够深入。本文以贵州省毕都高速公路鸡公山隧道为背景,通过现场调研、监控量测和数值模拟等方法,对强渗流条件下山岭分离式隧道围岩变形进行了分析,主要研究成果如下:(1)从隧道渗流特征入手,对鸡公山隧道拱顶、拱底两侧和边墙渗漏水现象进行了分析,并对隧道围岩裂隙发育情况、边墙渗漏水频率进行了统计,结果表明,鸡公山隧道在地下水强渗流作用影响下出现的地质灾害问题较为严重。(2)针对鸡公山隧道围岩变形进行了现场监控量测,分析了该隧道开挖过程中不含水段、弱渗水段和强渗水段的隧道围岩竖向位移及水平位移规律,分析表明,隧道围岩稳定性与变形受强渗流作用的影响十分明显。(3)针对隧道渗流参数难以确定的现状,提出了一种符合山岭分离式隧道在强渗流条件下的围岩参数验证方法;通过设置多组参数(渗透系数和孔隙率)进行数值模拟,将模拟结果与现场实测数据进行对比验证,得到强渗流条件下隧道渗流参数平均值,并分析了不同渗透系数和孔隙率条件下山岭分离式隧道围岩的孔压分布、水平侧移和隧道沉降规律。(4)利用FLAC3D数值模拟软件,对鸡公山隧道开挖支护过程进行了渗流耦合模拟运算,并将数值分析结果与现场数据比对,应证了模型的可靠性,并在此基础上分析了强渗流作用下隧道开挖过程中围岩的竖向位移、水平位移变化规律以及不同参数条件下的隧道围岩变形规律。
[Abstract]:With the continuous development and perfection of traffic engineering construction in our country, the highway construction gradually extends from the high population density plain area to the mountain heavy hill area, and the mountain tunnel construction more and more highlights its importance. In the mountain tunnel construction project, the complexity of mountain conditions leads to the diversity of rock (soil) structure conditions and geological conditions. In the process of tunnel construction, there are often problems such as collapse of arch roof or instability of large deformation, which greatly increases the difficulty of capital investment and construction. The study of surrounding rock deformation in Shanling tunnel mainly focuses on the adverse effect of the reduction of surrounding rock mechanical parameters on tunnel construction and the corresponding construction control measures, and on the mechanical effect of underground water seepage in tunnel surrounding rock. Especially, the research on surrounding rock deformation analysis of mountain tunnel under strong seepage condition is not deep enough. This paper takes Jigongshan Tunnel of Bidu Expressway in Guizhou Province as the background, through field investigation. Monitoring measurements and numerical simulation methods are used to analyze the surrounding rock deformation of mountain separated tunnel under the condition of strong seepage. The main research results are as follows: 1) starting with the seepage characteristics of the tunnel, the arch roof of Jigongshan tunnel is analyzed. The phenomena of leakage on both sides of arch bottom and side wall are analyzed, and the development of cracks in surrounding rock of tunnel and the frequency of leakage of side wall are analyzed, the results show that. Jigongshan Tunnel under the influence of the strong seepage of groundwater, the geological hazard problem is more serious. 2) the deformation of surrounding rock of Jigongshan Tunnel is monitored and measured on the spot. The vertical displacement and horizontal displacement of surrounding rock of the tunnel in the process of excavation without water, weak seepage and strong seepage are analyzed. It is obvious that the stability and deformation of tunnel surrounding rock are affected by strong seepage. A method for verifying the surrounding rock parameters of the separated mountain tunnel under the condition of strong seepage is put forward. The numerical simulation is carried out by setting a number of parameters (permeability coefficient and porosity), and the simulation results are compared with the field measured data to get the average value of the tunnel seepage parameters under the condition of strong seepage. The distribution of pore pressure, horizontal lateral displacement and tunnel settlement under different permeability coefficient and porosity of the surrounding rock of mountain separated tunnel are analyzed. (4) the numerical simulation software of FLAC3D is used to simulate the distribution of pore pressure, horizontal lateral displacement and tunnel settlement. The seepage coupling simulation of the excavation and support process of Jigongshan Tunnel is carried out, and the reliability of the model is verified by comparing the numerical analysis results with the field data. On this basis, the vertical displacement, horizontal displacement and deformation of surrounding rock in the excavation process of tunnel under the action of strong seepage are analyzed.
【学位授予单位】：湘潭大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U451.2

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