地铁隧道围岩力学参数反演及稳定性预测分析

发布时间：2018-06-04 23:48

本文选题：有限元强度折减法 + 力学参数反演　；参考：《山东科技大学》2017年硕士论文

【摘要】：随着城市现代化步伐的加快,交通拥堵问题逐渐受到人们关注。青岛这座城市也不例外,道路窄、车辆多是青岛交通现在面临的主要问题,因此地下交通的开发被提上日程。城市地下轨道交通的建设,能够在很大程度上缓解地面拥堵问题,而且能够减少当前城市普遍面临的噪声污染、城市美观等问题。大量地铁隧道的建设,对其安全稳定性及围岩性质分析预测能力提出了更高要求。本文基于有限元强度折减法以及反演围岩力学参数,分析预测了城市地铁隧道围岩稳定性,研究如下:(1)本文首先对比分析了有限元强度折减法的计算优势,并采用有限元强度折减法研究了青岛上覆分层岩土浅埋地铁隧道围岩稳定性。分析了浅埋双线隧道围岩失稳破坏机理,运用有限元软件ANSYS,建立了三维数值模型,模拟计算了围岩的塑性区发展以及破坏面位置。研究表明,浅埋双线隧道破坏首先从两隧道中间岩体拱脚处开始,而拱顶应力较小,破坏时中间岩体塑性区贯通,将塑性应变最大点连接即为围岩破坏面。(2)文中考虑多种因素分析验证了稳定性结论的可靠性。分别考虑了不同隧道埋深、不同双线隧道间距对隧道稳定性影响;分析了隧道在不同埋深、所处不同围岩类别条件下围岩安全系数变化规律。研究了隧道稳定性对围岩各个力学参数的敏感度,得到了一系列结论。(3)提出了将最小安全系数法及相对位移法结合反演计算围岩力学参数的改进方法,验证了改进后的方法在反演力学参数方面的可行性。并以青岛地铁隧道工程为背景,采用新方法反演了青岛地铁隧道围岩力学参数,并验证了计算参数精确性。论文最后基于改进后的反演方法计算得到的围岩力学参数,结合有限元数值模拟计算,分析预测了青岛地区拟开挖隧道围岩稳定性,预测结论为地铁隧道的安全施工提供了依据。
[Abstract]:With the acceleration of the pace of urban modernization, traffic congestion has gradually attracted people's attention. Qingdao this city is no exception, the road is narrow, the vehicle is the main problem that Qingdao traffic faces now, so the development of underground traffic is put on the agenda. The construction of urban underground rail transit can alleviate the problem of ground congestion to a great extent and reduce the problems of noise pollution and urban aesthetics. With the construction of a large number of subway tunnels, higher requirements are put forward for their safety and stability and the ability to analyze and predict the surrounding rock properties. Based on the finite element strength reduction method and the inversion of the mechanical parameters of surrounding rock, the stability of surrounding rock of urban subway tunnel is analyzed and forecasted in this paper. The stability of surrounding rock of Qingdao overlying stratified rock and soil shallow buried subway tunnel is studied by using finite element strength reduction method. In this paper, the failure mechanism of surrounding rock in shallow double-line tunnel is analyzed, and a three-dimensional numerical model is established by using finite element software ANSYS.The development of plastic zone and the location of failure surface of surrounding rock are simulated and calculated. The results show that the failure of shallow double track tunnel begins at the arch of the middle rock mass of the two tunnels, and the stress of the arch top is small, so the plastic zone of the intermediate rock mass is broken through. In this paper, the reliability of the stability conclusion is verified by considering a variety of factors. The influence of different tunnel depth and double tunnel spacing on tunnel stability is considered, and the variation law of surrounding rock safety factor is analyzed under different buried depth and different surrounding rock types. In this paper, the sensitivity of tunnel stability to the mechanical parameters of surrounding rock is studied, and a series of conclusions are obtained. An improved method is proposed to inverse calculate the mechanical parameters of surrounding rock by combining the minimum safety factor method with the relative displacement method. The feasibility of the improved method in inversion of mechanical parameters is verified. Taking Qingdao subway tunnel project as the background, the mechanical parameters of surrounding rock of Qingdao subway tunnel are inversed by a new method, and the accuracy of calculation parameters is verified. Finally, based on the mechanical parameters of surrounding rock calculated by improved inversion method, combined with finite element numerical simulation, the stability of surrounding rock of excavated tunnel in Qingdao area is analyzed and forecasted. The prediction results provide the basis for the safe construction of subway tunnel.
【学位授予单位】：山东科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：U451.2

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