【作者】 吕娉霏；

【导师】 陈志新；

【作者基本信息】 长安大学 ， 防灾减灾工程及防护工程， 2011， 硕士

【摘要】 我国大城市交通紧张状况在改革开放初期就已呈现出来。目前各大城市道路交通条件严重恶化,车均道路面积每年以10%-15%的速度下跌。因此,发展城市快速轨道交通,在市中心区建地下铁道,以代替地面汽车交通,不仅可以缓解地面道路阻塞和居民乘车难的问题,还可以节约能源和土地资源,有利于城市环境保护。但是,随着经济的发展,市中心区地下空间也越来越紧张,各种地下管线,地下构筑物,特别是高楼大厦的地下室和基础正在不断地占领地下空间,导致地下铁道建设空间不足,为了解决这一问题,设计人员不断更新地铁车站和区间结构形式,相应的施工技术不断进步,新的施工方法随之出现并以较快的速度发展,浅埋暗挖洞桩法就是其中很有代表性的一种工法。这种工法在传统浅埋暗挖分部法的基础上综合了盖挖法的特点,并且灵活多变,适应性很强。目前这种施工方法在北京、沈阳等地的地铁建设中广泛应用,并且得到了迅速的发展,这些工程实例充分证明,在软岩或土质地层条件的情况下进行浅埋大断面开挖,采用PBA工法是有效可行的,并且值得深入研究和广泛推广。但是,目前针对这一工法的理论研究还不够深入,对于它的工作机理以及适用条件的理论分析还不够详细。这对于该工法的进一步发展和推广是非常不利的。本文主要是依据目前地下结构设计及计算理论中的地层结构法,以有限差分法为计算手段,借助MIDAS/GTS数值计算模拟软件,针对浅埋暗挖洞桩法的自身工法特点进行了施工过程模拟。通过对计算结果的处理和分析得出了各主要施工阶段,地层的位移变化规律,地层应力变化规律,并且与实际的监测数据进行对比,得出各施工阶段地层位移对地下管线的影响。本研究的结论可对今后浅埋暗挖洞桩法设计与施工具有一定的理论指导意义。更多还原

【Abstract】 The big city traffic tension problem has appeared in the early reform and opening up days.Currently, the traffic condition of big cities are getting worse, the average road areas of cars are falling down by the speed of 10%-15% per year.Therefore,develop the city fast railway transportation,build the underground railway in the downtown area, in replace of the ground automobile traffic,it can not only ease the ground road obstruction and the residents transportation problem,but also can save energy and land resources,and also be benefit for the city environmental protection.But,with the economic development,the underground space in the downtown area are getting less and less,many kinds of underground pipelines, underground structures,especially the basement and the foundations of the high buildings and large mansions are occupying the underground space,which brings about the insufficient space problem of the underground railway construction.In order to solve this problem,the designers are updating the structure form of the subway stations and the subway intervals, improve the corresponding technology appeared and developed with a high speed.The PBA method is a representative one. This method synthesized the cover excavation method’s characteristics in basis of the traditional shallow buried excavation method, which is not only agile and changeable but also adaptable.At present,this construction technology is widely used in the construction of the Beijing and Shenyang underground railway,and developed with a high speed.These engineering examples sufficiently proof the truth that in the condition of soft rock or soil strata,the PBA technology is effective and feasible for the shallow buried and large section excavation.It is worth in-depth research and widely promoted.But at present,the theoretical research of its working mechanism and applicable condition is not detailed,which is adverse for the development and promotion of this construction technology.This article is mainly according to the strata structure method which is among the present underground structure design and calculation theory,at the means of finite difference method, with the numerical simulation the construction process which is aiming at the PBA method’s characteristic. Through the processing and analysis of the calculation results, we can conclude the stratigraphic displacement change rule,the stratigraphic stress change rule,then contrast with the actual testing data which can get the conclusion of the influence of underground pipeline which caused by the construction stage.The conclusion of this research may become a theoretical guidance of the design and construction of the PBA technology.更多还原