【作者】 丁祖德；

【导师】 吴从师；

【作者基本信息】 长沙理工大学 ， 岩土工程， 2008， 硕士

【摘要】 连拱隧道具有占地面积少,线形顺畅和桥隧衔接好等优点,在实际工程中得到了广泛应用。但是,连拱隧道跨度大,高跨比小,施工工序繁多,对围岩多次扰动,隧道受力特性复杂。因此,全面了解和掌握连拱隧道动态施工力学特性,优化连拱隧道动态施工效应,对连拱隧道的设计和施工具有重要意义。本文依托陈家桥隧道工程,结合当前国内外对连拱隧道的研究特点以及连拱隧道施工方法现状,应用有限元软件MIDAS/GTS对不同围岩条件和不同施工方法下连拱隧道的施工力学过程进行三维有限元分析,并结合隧道施工现场的监控量测,研究复杂工序下连拱隧道的受力特性,并对施工过程进行优化分析。主要研究内容包括:1.分别建立了连拱隧道Ⅲ级围岩段中导洞-上下台阶法和中导洞-全断面法,Ⅳ、Ⅴ级围岩段三导洞法开挖的三维动态施工全过程弹塑性模型,研究了不同围岩条件下典型开挖阶段围岩及支护结构受力特性。2.对陈家桥隧道的现场监控量测资料进行了分析,并与开挖模拟的数据进行了对比,验证了数值模拟的可靠性。3.分析了Ⅲ级围岩条件下隧道掌子面与初次支护结构的合理距离问题,进一步探讨了不同围岩条件下单洞开挖过程中的空间效应以及左右洞相互影响问题,得出单洞工作面间的合理间距以及左右洞工作面间的合理间距。更多还原

【Abstract】 Multi-arch tunnel is widely used in practice because of its advantages of small area of project, the flowing line and good connection between the tunnel and bridge. However, owing to its large span, small ratio of its altitude and span, complicated procedure of construction and repeated disturbance to surrouding rock, its characteristics are very complex during the different excavating stages. Therefore, it is significant to know and understand the mechanical characteristics of excavating and supporting as well as to optimize the process of construction for the design and construction of the multi-arch tunnel.Relying on Chenjiaqiao tunnel project, the construction process of tunnel under different surronding rock conditions and various construction methods has been analyzed with 3D FEM analysis of MIDAS/GTS program, combined with the study of the characteristics and the current construction methods of multi-arch tunnel in dometic and abroad.The mechanic behavior problems under complex construction process has been studied. The construction process has also been optimized by the analysis of the monitoring measured data. The main contents of the research in this paper as follows:1. The 3D elastoplastic model of multi-arch tunnel has been set up, which contains gradeⅢ,ⅣandⅤsurrouding rock, in gradeⅢsurrouding rock with such two methods as middle-pilot-and-half-section and middle-pilot-and-full-section, in gradeⅣandⅤsurrouding rock with such a method as three-pilot. The stress of the surrouding rock and supporting structure in typical excavation stage under these three excavation methods has been simulated and analyzed.2. The monitoring data in Chenjiaqiao tunnel has been analyzed and it has been compared with the simulated data.The results show that the numerical simulation is reliable.3. The reasonable distance between preliminary support and excavation face in gradeⅢsurrouding rock has been analyzed. The space effect during the tunnel construction and the transaction between the left hole and the right hole have also been analyzed. In the end, the reasonable distance of working face in one hole and between the left hole and right hole has been listed.更多还原