公路隧道开挖尺寸与支护措施优化研究

发布时间：2018-03-23 22:42

本文选题：隧道　切入点：开挖尺寸　出处：《重庆交通大学》2015年硕士论文

【摘要】：随着我国经济的迅速发展,公路隧道工程越来越多,隧道的形式、地质、水文、环境等条件的复杂多变,出现了风险事故更加多样,安全问题越发突出的情况,同时,在隧道的开挖施工及支护问题上,虽然依照新奥法,但施工过程中开挖的尺寸、支护的措施存在着不合理、不安全、不经济等问题。合理的施工开挖尺寸的确定和支护手段的优化是目前隧道工程施工急需研究的一个方面。本文以两车道四级围岩的公路隧道为研究对象,运用ANSYS有限元软件来模拟分析,计算出不同施工设计参数时的应力位移变化,分析围岩轴力弯矩、弹性抗力区、脱离区、应力应变关系等,对隧道开挖设计参数不同时的稳定性以及确定开挖尺寸时的有效支护问题进行了研究分析。主要工作如下：①运用弹塑性理论,研究分析了隧道初始地应力状态、开挖后的受力状态以及支护后的内力变化规律,对模型建立的几个影响因素进行了总结分析,确立了数值模拟参数的选取；②通过对隧道的开挖模拟,分析结构的应力位移变化情况,确定不同开挖尺寸时的结构稳定性系数,进而来确定一种合理的开挖尺寸设计；③运用ANSYS有限元分析软件,对工程施工进行精确适用的数值模拟分析,采用D-P理论,分析台阶法开挖时,不同的上台阶开挖高度情况下的结构稳定性及应力应变位移,通过对隧道抗力区、脱离区的分析,优化比选出较为合理的开挖设计；④对上台阶开挖高度为4m的开挖方案进行分析,根据围岩压力状态和抗力区、脱离区范围,对脱离区进行局部支护,施加一个支护抗力,通过改变支护抗力、泊松比、弹性模量的大小,计算不同情况下的安全系数,对围岩的支护要求进行合理的区间分析,得出较为安全的支护设计,改善围岩的应力情况。为隧道施工提供更好的设计依据和技术支持,保证工程的安全顺利进行。
[Abstract]:With the rapid development of China's economy, more and more highway tunnel engineering, tunnel, geological, hydrological, environmental and other conditions of the complex, the risk of accidents is more diverse, security issues become more prominent, at the same time, in the tunnel excavation and support issues, although in accordance with the new Austrian law, but in the process of excavation size, supporting measures are not reasonable, safe, economic and other issues. The excavation and support method for determining the size of the optimization is a research on construction of tunnel engineering. At present the urgent need to the two lane highway tunnel four grade rock as the research object. Simulation analysis using the finite element software ANSYS to calculate the design parameters for different construction stress analysis of surrounding rock displacement variation, axial force moment, elastic resistance zone, from the region, relation between stress and strain, and the design parameters of tunnel excavation Analyzed the stability and effective support to determine the size of the excavation supporting problem. The main work is as follows: the use of elastic-plastic theory, research and analysis of the initial stress state after the excavation of tunnel, the stress state and supporting internal force change rules and influence factors of the model are analyzed, the establishment of the parameters of numerical simulation; through the simulation on the tunnel excavation, analysis of structure change of stress and displacement, determine the structure stability coefficient of different excavation size, and to determine a reasonable excavation size design; the use of ANSYS finite element analysis software, numerical simulation and analysis of precision for engineering construction using D-P theory, analysis, bench excavation, different step excavation height and structure stability under the condition of stress strain and displacement, through the tunnel resistance area, detachment The analysis of excavation design optimization is selected more reasonable; the step excavation height of excavation scheme of 4m were analyzed, according to the state of surrounding rock pressure and resistance area, out of range, from local area to support, applying a supporting force, by changing the supporting force, Poisson ratio, elastic modulus size, calculation of safety coefficient under different conditions were analyzed, the reasonable range of surrounding rock support requirements, the safe support design, improve the surrounding rock stress. Provide better design basis and technical support for tunnel construction, to ensure the safety of the project smoothly.

【学位授予单位】：重庆交通大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U455

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