车站附属结构平顶直墙施工措施及控制要点

Construction Measures and Control Points for Flat Top Straight Walls of Station Ancillary Structures

地铁车站位于城市繁华地段,出入口设置于两侧人行道,受地下管线的影响,及周边环境影响,洲石路站过街通道采用浅埋暗挖施工。附属出入口基坑开挖施工过程中,出现越来越多的平顶直墙结构,平顶直墙结构二衬施工时,临时支撑处理措施分两种形式:一是在二衬施工前更换支护;二是在二衬砌施工后更换支撑。通过总结以往施工经验,依托深圳地铁12号线工程洲石路站过街通道工程实践,研究形成一套暗挖平顶直墙断面后拆撑二衬施工工艺,操作简便、安全性高、节约成本、质量可靠、节约工期,总结相应的施工工法和关键技术。

The subway station is located in a bustling urban area,with entrances and exits set on sidewalks on both sides.Due to the influence of underground pipelines and surrounding environment,the pedestrian passage at Zhoushi Road Station is constructed using shallow buried and concealed excavation.During the excavation and construction process of the foundation pit at the affiliated entrance and exit,more and more flat top straight wall structures have emerged.When constructing the second lining of a flat top straight wall structure,temporary support measures can be taken in two forms:one is to replace the support before the construction of the second lining,and the other is to replace the support after the construction of the second lining.By summarizing past construction experience and relying on the practice of the Zhoushi Road Station Street Crossing Project of Shenzhen Metro Line 12,a set of construction techniques for dismantling and supporting the secondary lining after the formation of a hidden excavation flat top straight wall section are studied.It has the advantages of simple operation,high safety,cost saving,reliable quality,and time saving.At the same time,corresponding construction methods and key technologies are summarized.