【作者】 曲世韡；

【导师】 张顶立；

【作者基本信息】 北京交通大学 ， 岩土工程， 2010， 硕士

【摘要】 隧道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,也会涌现出大量的岩土工程技术问题需要解决。在市区修建地铁隧道工程,施工所引起的地面沉陷将有可能危及周围建筑设施和地下管线等的安全,造成严重的经济损失和社会影响。因此,这些都为地铁隧道向深埋方向发展,已成为城市地铁工程建设中必须解决的一项重要课题。本文通过对城市地铁隧道开挖的数值模拟分析得出：①总结了北京典型地层条件下浅埋暗挖法隧道开挖引起的地层变形的机理和规律,对地层变形的整个过程进行了详细的描述,总结了浅埋暗挖法的施工原理。并总结了地层变形控制原理的原理,以及技术措施。②过数值模拟,研究了埋深对地表沉降槽等相关参数的影响。得出地表最大沉降值、地层损失率和地表沉降槽反弯点距离随埋深变化的规律。③地铁隧道深埋将减小施工对地面及地层环境的影响,其中对减小地表沉降有着很大的作用。而要界定地铁隧道深浅埋,找出压力拱则是较为清晰有效的方法。本文讨论了压力拱的形成原理、定义以及压力拱的形成规律。并分别讨论了影响压力拱形成规律的几种因素,埋深、围岩力学参数、隧道跨度等。继而讨论了单一围岩条件下和分层围岩条件下压力拱的形成规律。最后以压力拱形成与否作为参照,研究浅埋隧道的分界方法。更多还原

【Abstract】 It is predicted that a great deal of urban metro engineering will be constructed at early-middle period in the 21st century based on flourish metro engineering foreground nowadays, and at one time many geotechnical problems will also come forth. Large land subsidence value induced by metro tunneling can lead to that road surface, buried pipelines and buildings and so on are damaged. Furthermore, bad economic loss and social effect can be brought about. As a result, it is an urgent realistic problem that land subsidence induced by urban underground engineering is forecasted and controlled so as to ensure the safety of close-by building and buried pipeline.By the method of probability statistical analysis and numerical calculation about Beijin metro engineering:①Base on the typical formation conditions of Beijng, the mechanism and the law of strata deformation caused by Shallow Mining Method are summarized. At the same time, the whole process of ground deformation is described in detail. The Principle of Shallow Mining Method is concluded, and the feathers and the method of support design are described in this paper;②By the probability statistical analysis on field monitoring measurement data of Beijin metro line 5 and line 10 in detail, the reasonable control standards of the ground settlement are given, which changes the situation of the single contol standards 30mm in Beijin metro engineering in the past.At the same time, based on the site construction monitor data of running tunnels and subway stations constructed by Mining Method, the curves of surface settlement troughs are fitted and the feather of formation loss rate and trough width parameter are deeply researched,which gives some relevant conclusions;③By the measure numerical simulation, the influence of the buried depth for the related parameters of surface settlement troughs are studied. The changing law of the surface maximum settlement value、the formation loss rate and the trough width parameter with increasing buried depth is given. Find the critical depth below which the influence for the ground surface caused by the construction of standard section interval tunnel by Shallow Mining Method is negligibly small.At the same time, the effect of primary support structure stress with increasing buried depth is researched and some important laws are found, then the range of buried depth below which it is considered that the formation can form the stable arch structure by itself is given. Finally, the positions of the formation arch structure in different buried depths and the changing rules of the position with increasing buried depth are given by the further study of the characteristics of formation settlement curves below different burid depths;更多还原