黄土区浅埋大断面隧道围岩变形分析

发布时间：2018-05-03 17:24

本文选题：黄土 + 浅埋　；参考：《石家庄铁道大学》2015年硕士论文

【摘要】：黄土区隧道由于黄土本身特殊的工程性质较常规土质隧道的受力变形特点更为复杂。黄土区隧道施工断面较大时,由于围岩条件差,施工总是面临很多难题,常常发生失稳,尤其是在埋深较浅时,其建设难度更是不言而喻。为了研究黄土区浅埋大断面隧道的变形特性,以及不同因素影响下隧道开挖引起的围岩及支护结构的变形规律,本文通过建立三维的数值分析模型对隧道的施工进行了数值模拟,并结合现场监控量测对隧道施工进行研究。本文以陕西省合阳县的如意隧道为工程背景,基于隧道的工程地质情况及隧道的设计尺寸,首先运用有限元软件对试验段断面DK75+60~DK75+95建立3-D数值计算模型,对如意隧道采用三台阶七步开挖法施工进行了数值模拟。分析了在开挖过程中围岩与支护结构的应力应变形态,综合分析模拟结果得出如意隧道采用三台阶七步开挖法施工具有可行性;其次,对现场监控量测的数据进行了回归分析,并将拟合的结果与实测结果及数值模拟结果进行了对比分析,得出数值模拟结果能够反应围岩的变形趋势,隧道的实测数据作为判定围岩是否稳定的依据具有可靠性;最后,分别建立了有无系统锚杆时的数值模型,仰拱一次性进尺深度为1 m、2 m、3 m时的数值模型及隧道一次性开挖进尺为1 m、2 m、3 m时的数值模型。通过对上述情况进行数值模拟,分析了施工时锚杆、仰拱一次性进尺深度及隧道开挖进尺对围岩及支护结构变形的影响。
[Abstract]:Loess tunnel is more complicated than conventional soil tunnel because of its special engineering properties. When the construction section of the tunnel in loess area is larger, because of the poor surrounding rock condition, the construction is always faced with a lot of difficult problems, which often lead to instability, especially when the buried depth is shallow, the difficulty of construction is even more self-evident. In order to study the deformation characteristics of shallow large section tunnel in loess area and the deformation law of surrounding rock and supporting structure caused by tunnel excavation under different factors, In this paper, the numerical simulation of tunnel construction is carried out by establishing a three-dimensional numerical analysis model, and the tunnel construction is studied in combination with on-site monitoring and measurement. Based on the engineering background of Ruyi Tunnel in Heyang County, Shaanxi Province, and based on the engineering geology of the tunnel and the design size of the tunnel, the 3-D numerical model of section DK75 60~DK75 95 of the experimental section is established by using the finite element software. Numerical simulation was carried out for the construction of Ruyi tunnel by using three steps and seven steps excavation method. The stress-strain pattern of surrounding rock and supporting structure during excavation is analyzed. The comprehensive analysis and simulation results show that it is feasible to construct Ruyi tunnel with three-step and seven-step excavation method. Secondly, regression analysis is made to the data of field monitoring measurement. By comparing the fitting results with the measured results and the numerical simulation results, it is concluded that the numerical simulation results can reflect the deformation trend of the surrounding rock, and the measured data of the tunnel can be used as the basis for judging the stability of the surrounding rock. Finally, the numerical simulation results can reflect the deformation trend of the surrounding rock. The numerical models with or without systematic anchors are established. The numerical models are established when the one-off depth of the inverted arch is 1 m ~ 2 m ~ (3 m) and the tunnel excavation is 1 m ~ 2 m ~ (3 m). Through the numerical simulation of the above situation, the influence of anchor rod, inverted arch one-off advance depth and tunnel excavation advance on the deformation of surrounding rock and supporting structure is analyzed.
【学位授予单位】：石家庄铁道大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U451.2

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