Construction Technology Study On Underground Passage Just Over The Operational Metro

摘要

This article Deals with the construction of metro passage leading to the first-story basement of Shanghai City Planning Exhibition Hall. Its construction condition is very unfavourable, because the passage is just over the operational metro, with the nearest distance between it and the metro tunnel being only 180mm. In addition, its surrounding is buried with a lot of pipes and just on the top of the passage, there is a 110Kv cable crossing it. In order to overcome these difficulties, up-to-down construction method is adopted----open cut at both ends of the passage, while concealed operation in the middle. The passage construction is done successfully by taking a series of technical measures, such as backfilling, time-space-effect excavation, bracing plus prestressing, informationized construction and so on. During the whole process of construction, the deformation of tunnel is only 1.05mm, the safety of metro tunnel, its surrounding pipes and buildings being well guaranteed.