Research On Construction Technology Of Puhuangyu Station Under Beijing Subway No.5 Line

Beijing five line of subway is an important south-north track in the traffic network of Beijing subways. Puhuangyu station lie in the crowded road of Puhuangyu, with more surface buildings. The station is excavated in the span of 22.6m and the height of 16.3m, wit the single arch-post and double-layer structure. The station is divided into twelve parts to excavate, each wide 7.5m and high 4m, with the protection of over-length pipe-shield. The wide passway has a large connection with the station and it is deeper and wider. The new working range opens here, with various working transform styles, more complicated space form strength and more difficult constructing organization. The application of CRD will be used in the construction with the principle of "small parts, short steps, becoming rings early, ring by ring". After the completion of excavating and the protection in initial stages, some reinforcing concrete, two sticks and middle baffles will be used in the structure in order to form frame structure.By the analysis of the two pre-protection methods, such as over-length pipe-shield and little-pipe note thick liquid, we have compared these two schemes from the perspectives of security, economy, time limit, technology, and determine to take the over-length pipe-shield scheme. We choose the rigs through calculating the strength of canopy back to towing bassoon. By testing the over-length pipe-shield, we determine the important technologies of back tow, mud system, making reservations and leading system, noting thick liquid by pipe-shield, staffing and efficiency, etc., in different soil layers, in order to lay a solid foundation for constructing concretely. Summarize the construction technology of utilizing unexcavate technology constructing of over-length pipe-shield. It will provide the basis of consulting for the subway construction in the future.To the project needing to be controlled strictly while constructing, monitor is designed. Scientific managements are necessary to guarantee construction security and process, according to the characteristics of the project. The sink and vault sink monitoring data are analyzed and predicted. According to these results, the rationality of the scheme of constructing has verified.