【作者】 史继尧；

【导师】 刘招伟； 余永强；

【作者基本信息】 河南理工大学 ， 工程力学， 2009， 硕士

【摘要】 本文简要的叙述了工程背景和国内外的研究现状并提出了研究的问题;介绍了目前地铁车站常用的施工方法,以及PBA(Pile-Beam-Arch)工法的施工工艺,并对此工法对地表沉降影响的规律及其地表变形的控制措施进行了分析;以青年大街车站为背景,建立了FLAC3D三维数值模型,分析了车站PBA工法动态开挖过程对地表沉降的影响。PBA工法是一个将传统的框架结构施工方法和暗挖法进行有机结合起来的新型方法,是在提前施作好的边桩、中桩和拱部初支的保护下,暗挖土体并施作二衬等结构的一种施工方法。在暗挖地铁车站的众多的施工方法中,PBA工法以其施工灵活、能较好的控制地表沉降、满足城市复杂的工程环境的要求等优点越来越为工程师所青睐。导洞的开挖是PBA工法中很重要的一个工序,由于导洞的开挖对地表沉降的影响具有非线性的路径相关性,即不同开挖顺序以及开挖进尺对周围环境的影响是不一样的,因此,本文依托沈阳青年大街地铁车站为工程背景,运用FLAC3D有限元数值计算软件,建立力学和计算模型,分析了采用不同开挖顺序下的六种施工方案分别在不同开挖进尺下对地表沉降影响的规律,对比模拟结果,从而得出对周围环境影响最小的施工方案。并通过将数值模拟结果和现场实测数据进行对比分析,总结出PBA工法不同施工阶段对地表沉降产生的影响规律。从而得出一些结论,对以后类似工程的设计和施工具有一定的指导意义。更多还原

【Abstract】 This paper reviewed the engineering background and the domestic and oversea present situation of research, and introduced conventional construction methods of PBA , analyzed the ground settlement law caused by PBA construction and discussed surface deformation control measures. Combined youth street subway station and construct FLAC3D numerical model and analyzed the dynamic excavation process effect of PBA method on ground settlement and make a comparative analysis of numerical simulation and monitoring result in practice.PBA construction method is a new method combining traditional frame construction method with undermining method, which undermine soil and construct second staining under the care of slope stake, center stake and arch prefabricated. PBA construction method is remarkable for easy application, settlement controlled effectively and meeting complex city engineering environment, so this construction method is more popular within engineers than many other construction methods.Pilot tunnel excavation is an important working procedure, and is nonlinearity route relative to ground settlement induced by excavated that different excavation sequences and footages bring about the different effect on the surrounding environment. The paper used numerical simulation software FLAC3D, constructing mathematical mechanics model and further analyzed different excavation footage effect on ground settlement on the condition of different excavation sequences of 6 types of construction methods. Through comparing numerical simulation results, the construction plan that is minimal effect on the surrounding environment can be determined. Through comparative analysis between real data and numerical simulation results, the influence laws of ground settlement caused by different construction stage of the PBA construction method are summarized. It is important to guide similar projects design and construction for these laws.更多还原