【作者】 宋英学；

【导师】 李彰明；

【作者基本信息】 广东工业大学 ， 岩土工程， 2012， 硕士

【摘要】 近年来,随着我国交通运输建设事业的高速发展以及隧道与地下工程施工技术水平的不断提高,国内已经成功修建了一些复杂的浅埋大跨隧道。但是,目前对隧道力学行为的研究一般局限于开挖过程,如隧道开挖地表沉降控制、施工工序、隧道的稳定性、中隔墙的加固措施等。在施工过程中临时支撑的拆除时机,方法以及拆除的步长,对隧道结构的安全性与围岩的稳定性具有很大的影响。本文正是基于这点而展开研究。论文以深圳麒麟山隧道重要工程为背景,着重分析影响隧道临时支护拆除的因素,即：拆除过程所引起的位移沉降,拆除过程中的衬砌应力分布,剩余钢架的安全稳定性等,并对这些因素进行分析,找出他们之间的内在联系和规律。在不同的方案当中,运用位移相对比较法,辅之以安全稳定性原则,应力分布的情况来确定合理的拆撑步长。主要研究内容包括以下三个方面：(1)采用有限元法对大跨复杂隧道在浅埋软弱围岩地段的施工方案进行数值分析,对临时支护的拆除拟定了四种拆除顺序,对每种拆除顺序所引起的位移沉降,衬砌应力分布,剩余临时钢架的稳定性进行了分析比较,采用李彰明教授提出的相对比较法确定出了先横撑后竖撑,左洞先左侧后右侧,右洞先右侧后左侧的拆除顺序。(2)通过三维空间有限元模型采用二维分析中所得合理的拆除的顺序对隧道临时支护的拆除过程进行模拟,分别拟定四种拆撑步长,一次性分别拆除临时支撑6m、9m、12m与15m。对每种拆撑步长所引起的位移沉降,衬砌应力分布情况,剩余临时钢架的安全稳定性进行分析,采用数值对比分析的方法来确定方案中的最佳方案,提出纵向一次性拆除支撑的合理步长。(3)对隧道施工期间的现场原位监测结果分析,分析隧道开挖期间围岩收敛变形,并与数值模拟进行对比分析,为隧道安全施工和支护参数的调整提供理论依据和技术指导。更多还原

【Abstract】 In recent years, with the rapid development of China’s transportation construction and the increasing levels of the underground engineering technology, we have successfully built a complex of shallow large span tunnels。However, the mechanical behavior of the tunnel is generally limited to the excavation process, such as controlling the tunnel surface subsidence in the excavating, theconstruction process, the stability of the tunnel and the reinforcement measures.The timing of removing the temporary support, and the step of the dismantling, do a large impact on the safety of the tunnel structure and the stability of the surrounding rock in the process of constructing. This article is based on this to expand the study.In the background of Shenzhen Qilin Mountain Tunnel project, this paper analyzes the factors which impact the removing of the tunnel temporary support. and then analyze the main factors to find out the intrinsic link and laws between the main factors. The research topics include the following two aspects:(1) Using the finite element method to simulate the constructing program of the complex large cross-plane tunnels in the shallow soft surrounding rock and then put forward the reasonable order of the removing of temporary support by the plane strain model.(2) Using the three-dimensional finite element model to simulate the constructive process of removing the temporary support and then put forward a reasonable step for removing the temporary support one time after comparing analysis.(3) Analyzing the site monitoring results and the deformation of the rock convergence during the tunnel construction and then comparing the results with the results of the numerical simulation, to provide a theoretical basis and technical guidance for the safety and support parameters of the adjustment of tunnel constructing.更多还原