低净空下盖挖法地铁施工关键技术及安全管控措施

Key Technologies and Safety Control Measures for Subway Construction by Cover-excavation Method under Low Headroom Conditions

摘要:

以新建福州某地铁车站工程为例，对地铁车站盖挖法施工中所面临的地面交通改移、低净空下超深地下连续墙施工、换乘车站基坑开挖以及特殊施工缝的防水施工等关键技术进行分析总结，并提出了应对方案。采用“借一还一”的交通改移方案、低净空下成槽机改制及钢筋笼分节吊装技术、合理的基坑开挖组织以及特殊施工缝多重防水工艺，同时，针对盖挖法提出了照明通风的专项安全管控措施。实践表明，通过以上关键技术及安全管控措施，有效地保障了地铁车站施工期间无安全事故，并确保了周边既有建筑与运营地铁的结构安全，可为类似低净空下盖挖法地铁建设提供参考。

Abstract:

Taking a subway station project in Fuzhou as an example, the key technologies encountered in the construction of subway stations by cover-excavation method, such as ground traffic diversion, construction of ultra-deep diaphragm walls under low headroom conditions, foundation pit excavation for transfer stations and waterproofing of special construction joints are analyzed and summarized. And the corresponding solutions are proposed, such as the "borrow-one-return-one" traffic diversion scheme, modification of trenching machines and segmented hoisting technology for reinforcement cages under low headroom, rational organization of foundation pit excavation and a multiple waterproofing process for special construction joints. Additionally, the specific safety control measures for lighting and ventilation in the cover-excavation method are put forward. The practice shows that these key technologies and safety control measures can effectively ensure zero safety accidents during the construction of subway stations and guarantee the structural safety of surrounding existing buildings and operational subway lines, which can provide a reference for similar subway constructions by the cover-excavation method under low headroom conditions.