既有地铁枢纽车站大规模节点换乘改造关键施工技术

Key Construction Techniques for Large-Scale Transfer Nodes Renovation of Existing Metro Hub Stations

为解决既有地铁车站节点换乘改造涉及的空间受力转换、拆建方案、既有车站保护等多方面难题,依托深圳地铁黄木岗站综合交通枢纽改造工程,通过工程类比、模拟计算、现场验证等方式,梳理既有地铁车站大规模节点换乘改造所面临的施工重难点和针对性措施,形成一套完整的关键施工技术。研究结果表明:1)为确保既有车站正常运营及结构安全,改造应遵循“先支撑、后拆除,跳仓分序、先柱后梁,逐次实现受力转换”的原则;2)设置抗倾覆措施的临时支撑体系,采用自动伺服系统自动补偿临时钢立柱与结构板之间的空隙,顺利完成临时柱到永久柱的结构受力体系转换,可确保变形可控;3)采用型钢骨架+吸音棉+防火消音板制作的新型多功能围挡,可有效降低改造施工对车站运营的影响;4)围护结构建议采用人工手持风镐破除,主体结构可根据拆除部位及是否保留钢筋分别采用人工破除、金刚石绳锯切割及高压水射流破碎法分序跳仓破除;5)施工过程中应重点做好抗浮、防水与监测工作,严控结构变形、不均匀沉降及差异沉降。

Large-scale transfer nodes renovation of the existing metro hub stations involves many issues such as space stress conversion,demolition and construction scheme,and existing station protection.Relying on the comprehensive transportation hub transformation project of the Huangmugang station of Shenzhen metro,the construction difficulties and corresponding countermeasures faced in large-scale transfer nodes renovation of the existing metro stations are summarized using engineering analogy,simulation calculation,and construction verification,obtaining a complete set of key construction techniques.The research results reveal the following:(1)To ensure the normal operation and structural safety of the existing stations,a renovation principle,supporting first,then dismantling,sectional construction,and columns before beams,is established to gradually achieve force conversion.(2)A temporary support system with antioverturning measures is arranged,and an automatic servo system is used to automatically compensate for the gap between the temporary steel column and the structural plate,successfully achieving the structural stress system conversion from temporary column to permanent column,and ensuring controllable deformation.(3)A novel multifunctional enclosure composed of steel skeleton,sound-absorbing cotton,and fire-resistant and sound-absorbing boards effectively minimize the impact of renovation construction on station operation.(4)Manual hand-held air picks are recommended to use to break down the enclosure structure,and manual breaking,diamond rope saw cutting,and high-pressure water jet crushing methods can be used for main structure according to specific requirements.(5)During construction,key measures such as anti-floating,waterproofing,and monitoring should be employed to strictly control structural deformation,uneven settlement,and differential settlement.