盖挖逆作法施工地铁车站叠合墙综合防水体系

Comprehensive Waterproof System for Composite Walls in Metro Station Constructed by Cover-excavation Reverse Method

目的:盖挖逆作法施工地铁车站叠合墙中无法铺设柔性防水层,一旦发生渗漏水不仅影响结构耐久性,同时也会增加后期封堵费用,因此叠合墙结构防水是地铁车站工程施工的重点和难点,需进行针对性研究。方法:分析了叠合墙的地下连续墙、内衬墙及其他关键位置发生渗漏水的原因;以长沙地铁6号线朝阳村站工程为依托,介绍了叠合墙综合防水体系的多道防水技术,包括围护结构防水、防水涂料防水、渗漏点预处理、内衬墙防水和预埋注浆管防水;介绍了各道防水技术实施过程中所采用的新技术和新装置,并提出了相应的保障措施和注意事项。结果及结论:长沙地铁6号线朝阳村站自工程完工后的3年使用期间未发生渗漏水现象,表明所提出的叠合墙综合防水体系防水效果良好。

Objective:Flexible waterproof layers cannot be installed in composite walls of metro stations constructed by cover-excavation reverse method,because once water leakage occurs,it not only affects the structural durability,but also increases the cost of later sealing.Therefore,waterproofing for composite wall structure is a crucial and difficult aspect in metro station engineering construction,requiring targeted research.Method:The reasons for water leakage in diaphragm walls,inner linings and other critical locations of the composite walls are analyzed.Based on Changsha Metro Line 6 Chaoyangcun Station project,multiple waterproofing techniques in composite wall comprehensive waterproof system are introduced,including retaining structure waterproofing,waterproof coating,pre-treatment of leakage points,inner lining waterproofing,and pre-embedded grouting pipe waterproofing.New technologies and devices used in the implementation of each waterproofing technique are presented,along with corresponding safeguard measures and precautions.Result&Conclusion:During the three years of usage after the completion of Changsha Metro Line 6 Chaoyangcun Station,no water leakage occurred,indicating that the proposed composite wall comprehensive waterproof system performs well.