【作者】 琚国全；

【导师】 漆泰岳；

【作者基本信息】 西南交通大学 ， 桥梁与隧道工程， 2009， 硕士

【摘要】 随着城市地铁工程在我国的蓬勃发展,预计21世纪初至中叶将是我国大规模建设地铁的年代。与此相关,必然会涌现出大量的岩土工程技术问题需要解决,如群洞施工、大断面隧道施工等。无论采用何种方法在城市中修建地下工程,都不可避免对周边环境造成一定的影响,引起地表沉陷,危及周边建筑物和地下管线的安全,严重的引起工程事故,造成严重的经济损失和人员伤亡。因此如何在施工中保证施工安全和有效控制地表沉降已经成为城市地铁建设工程中一个亟待解决的重要课题。论文以广州地铁六号线东湖站暗挖段为工程背景,主要进行了以下几个方面的工作:1.通过总结前人的研究和经验,简要阐述了大跨度隧道的施工方法、受力特性及引起地表沉降的原因,为东湖站暗挖段大跨隧道施工提供理论支撑。2.通过工程类比,初步提出几种适合东湖站暗挖段隧道施工方法。根据暗挖段车站结构的要求,确定以中洞法施工为基础,侧壁采用导坑或者台阶法施工。运用FLAC^3D有限差分软件,模拟不同施工方法对围岩应力重分布、地表沉降、初期支护受力的影响,确定中洞加双侧壁导坑法为初选施工方法。在此基础上,应用模型试验对所选施工方法从围岩应力分布、地表及地层沉降控制的方面验证,确保施工安全和对周边环境的影响减小到许可的范围。3.通过对施工过程中监控量测返回的数据分析,验证了三维数值模拟和模型试验的合理性,为以后类似工程提供经验。论文针对广州地铁东湖站的特点,通过数值模拟和模型试验提出了切实可行的施工方案。广州地铁六号线东湖站大跨扁平隧道成功修建证明,在城市软弱围岩中修建大断面扁平隧道,通过将大断面隧道转化为几步合理的小断面开挖和控制爆破技术,不仅能保证施工的安全,而且能有效的控制地表沉降,减小对周边环境的影响。实践证明,这些方法对于城市地铁大跨度隧道都是行之有效的。更多还原

【Abstract】 It can be predicted that a great deal of urban metro engineering projects will be constructed in the early-middle 21st century based on flourish metro engineering foreground nowadays. But at the same time many geotechnical problems will also come forth, such as the construction of multi-tunnels, the construction of large span tunnel, etc. At present whatever methods are adopted, it is still impossibe to avoid some bad influences on the related environment, for instance, causing surface subsidence, endangering the surrounding buildings and underground pipeline safety, some of which will bring serious financial losses or even heavy casualties. Therefore, how to ensure the security of the construction and control the surface subsidence effectively is an important issu in the urban metro construction areas.Based on the East Lake station taken by shallow tunneling method of Guangzhou Metro 6th Line, the paper mainly includs the following aspects:1. Expounding the large span tunnel construction methods, mechanical properties and the reason of surface subsidence by summing up the past experience and research. And all of these provided theoretical support for the shallow tunneling large span East Lake Station.2. Giving some suggestion on several kinds of tunnel construction methods which are suitable for the wide-span East Lake shallow tunneling Station preliminary by contrasting the similar projects. In order to meet the needs of the station construction, three-dimensional numerical simulation and model test are employed to ensure the security of construction and reduce the impact on the surrounding environment.3. Proving the rationality of three-dimensional numerical simulation and model testing through analying the returned monitoring data, which will provid the experience for later similar projects.According to the characteristics of East Lake station, the paper gives a reasonable construction method by numerical simulation and model test. The sucefull practice on the large span East Lake station proved that preceding pilot tunnels, large-volume excavation divided into small ones, excavation of flank before that of center, upper before lower, arch before wall, is a good method which could effiectivel reduce surface subsidecne and its adverse effect on djacent buildings, in addition, some other measures are also taken to lessen vlast-induced vibration in the ground and surrounding structures. In a word, all methodes and steps mentioned above have already proved efficiency and practicalness in projects..更多还原