地下铁道SCB法扩挖双层车站结构与施工方案

为了统筹地铁区间隧道和车站施工,减少盾构施工中的非推进作业,提出在区间盾构隧道基础上扩挖双层地铁车站的结构施作方案( shield tunnel, cross-channel braced-frame, SCB),主要包括盾构隧道、横通道及框支结构等施作过程。以北京地铁实际工程为背景,对该工法的施工特点及结构特性进行了分析,对车站行车隧道几何关系、盾构衬砌的分块设计及基坑支护等关键技术进行了研究,并将其施工工期及造价与原工程施工方案进行了对比分析。研究结果表明,采用SCB法修建的车站结构及施工方案可行,并可减少投入盾构机数量,提高盾构机的使用效率,有显著的工期优势与经济效益。

Double-storey Station Structure and Its Construction Scheme With SCB Method for Subways

In order to plan the subway station structure construction and the interval tunnel construction as a whole, and to reduce non-promoting operation of the shield machine, an innovative subway station structure and its construction scheme named as SCB method, including several construction processes such as shield tunnels, cross-channel, braced-frame and etc. , was developed based on the interval shield tunneling. Taking a practical engineering of Beijing Subway as the background, the construction features and the structure characteristics with SCB method were analyzed. Several key techniques, such as the geometrical relationship between the running tunnel and the station structure, the segment design of the shield tunnel lining and the retaining structure of the foundation pit, were researched and developed. The construction period and cost with SCB method was compared with that by the original construction scheme. The study shows that the station structure and construction scheme with SCB method is feasible, the number of the shield machine to be equipped is reduced and the service efficiency of the shield machine is improved, and the structure and construction scheme with SCB method will have significant advantages in the construction period and cost.