为解决目前国内区间盾构施工和车站施工工期矛盾的问题，寻求盾构法在我国地铁工程中大规模应用的突破口，本文在对国外相关资料和工程实例大量查阅和分析的基础上，结合国内目前的经济和技术水平，提出了一种新型的解决盾构过站问题的车站施工方法：6．14m外径区间盾构先行贯通车站行车隧道的条件下，结合明挖法或暗挖法建造地铁车站。这是一个具有重要现实意义和非常紧迫的课题，在我国将有着广阔的应用前景。围绕该新型工法，采用数值模拟、模型试验和理论分析等多种研究手段，从新型车站结构方案设计、关键施工工艺、车站施工过程的模型试验和数值模拟研究及风险分析等方面进行了比较系统全面的研究，为今后盾构法在我国的大规模应用提供了技术储备。主要的工作和研究成果如下：（1）综合国内外相关资料和多位相关专家的意见，首先对盾构先行条件下拓展地铁车站这样一种新型的车站结构形式的设计原则进行了归纳总结；在此基础上提出了明挖拓展地铁车站和暗挖拓展地铁车站两种方案的共7种结构形式的设计构思，找到了适合北京地层的车站结构形式；对结构设计中的关键技术问题：盾构管片的设计原则、拼装方式和拼装位置及盾构管片与主体结构的连接节点设计等进行了详细的讨论分析。确保了结构方案能够满足国内目前的车站功能要求、建筑结构设计规范和技术经济要求。（2）盾构先行条件下拓展地铁车站施工技术中最为关键和最为特殊的、也即最为不利的一种工况是部分盾构管片的拆除，管片拆除过程中对开口环管片的保护措施决定了该新型工法的成败。在对国内外相关施工工艺大量搜集和整理的基础上，找到了解决该关键工艺的核心技术——盾构隧道外侧挡土隔离桩（Pile）+盾构隧道内临时钢管柱支撑（Column）+盾构管片纵向上的预应力（Pre-stress）共同组成的支撑体系（Support System），并完成了该新型支撑体系（简称桩-柱-预应力支撑体系或PCPrSS）的方案设计和施工工艺研究。研究表明该支撑体系在现有的技术和经济条件下是可以实现的。（3）借助1：10大比尺模型试验的手段，对本文提出的暗挖拓展的塔柱式车站的施工过程进行了详细的试验方案设计和实施，比较真实地再现了车站的施工过程。获得了盾构管片应变、预应力钢索应变和隧道内临时钢管柱支撑应变、盾构管片的收敛变形、车站洞周土体压力和地层变位等指标，随车站开挖的一般性的变化规律。分析认为在模型地层构造和地应力的条件下，试验开挖方案和支护方案能够保证车站洞室在整个施工过程中的安全稳定，且开挖过程中车站洞室周边未出现明显的开裂和变形突变，由此证明了本文提出的新型车站施工方法在施工工艺上是可行的。同时，借助FLAC3D有限差分法软件，对盾构先行条件下暗挖拓展的塔柱式车站进行了施工过程数值模拟研究，并将数值模拟结果和模型试验结果进行了比较分析。总体上看，两者所反映的车站拓展过程中的定性规律是一致的。进一步验证了本文提出的新型车站施工技术是可行的。（4）采用借鉴国外类似的工程经验资料统计、本文的研究成果、组织有经验或有资历的专家进行讨论、走访大量具有丰富工程经验的专家等多种识别方法，对本文提出的明挖拓展的立柱式车站和暗挖拓展的塔柱式车站分别进行了施工过程特殊风险源的识别和分析，并提出了应对风险的对策。
工业羊毛毡
In order to solve the contradiction of construction time limit for running tunnel constructed by shield method and station in domestic, and to seek for the breach of large-scale application for shield method in domestic subway engineering, a new-style station construction method has been brought forward in this paper based on large numbers of overseas project examples and domestic economy and technology level. The new-style station construction method is that the station will be constructed by shield method and tunneling method （or cut and cover method） under the condition of shield running tunnel. This is a very important and urgent research problem and has a wide application prospect.Surrounding the new-style station construction method, structural schemes and crucial construction technologies and model test and numerical simulation of station construction process and risk analysis have been researched roundly in this paper. The research methods include numerical simulation and model test and theoretical analysis and etc. The main work and the achievement are as follows:（1） Based on overseas literature information and advices of pertinent experts, structural design principle of the new-style station and seven conceptive structural forms have been conceived, and fit structural scheme for Beijing stratum conditions have been recommended. Crucial technologies which include the design principle and the assembled fashion and the assembled position of shield segments and also the connective node design of shield segment and structural main body have been discussed in detail. These study achievements insure that the structural schemes satisfy desired station function and code for design of building structure and domestic technology and economic level.（2） During the course of new-style station construction, the most crucial and the most especial and the most adverse step is dismantlement of partial shield segments, so the protection to the split ring segments decides the success or failure of the new-style station construction method. Based on the collection of relevant information about construction technics, A new support system which is made up of pile outside the shield tunnel and steel-tube column in the shield tunnel and prestress （for short PCPrSS）, has been commended. And the scheme design and the technics of PCPrSS have been discussed in detail. （3） In virtue of 1:10 large-scale model test, detailed experimentation scheme has been designed and implemented for the construction process of pylon shaft station. The variational rules of strain on the shield segments and the prestressed tightwires and the transient steel tube supports, and at the same time the variational rules of convergence of shield segments and soil pressure and displacement around the station tunnel have been achieved accordingly. It has been proved that the construction scheme is feasible under the condition of model stratum.At the same time, by dint of FLAC3D software, numerical simulation has been implemented for the construction process of pylon shaft station. As compared with the results of model test, the results of numerical simulation have showed the analogous qualitative rules. Therefore it is proved again that the new construction scheme is feasible.（4） By adopting many discriminating means, for example analogous engineering experience and study achievement of this paper and advice of pertinent experts, especial construction risks have identified and countermeasures to answer these risks have been also brought forward for the vertical shaft station and the pylon shaft station.