摘要
针对暮坪湘江特大桥主墩基础所在位置埋深大、覆盖层浅、水位深的特点,设计PLC工法桩围堰,作为基础施工时的挡水与围护结构。通过钢板桩与钢管桩组合的方式增强了锁口止水效果,节约了钢材用量,降低了施工成本。结合地层岩性与岩石抗压强度低的特点,选用旋挖钻机高效完成围堰刻槽施工,通过不同直径钻孔咬合的方式提高刻槽质量,减小刻槽盲区。考虑到中风化泥质粉砂岩遇水易崩解软化的特征,通过在已成槽内回填砂的方式防止槽壁塌陷。为保证封底质量,采用气举反循环法进行围堰吹砂施工。主墩基础施工效果较好,表明PLC工法桩适用于深水浅覆盖地层。
According to the characteristics of large buried depth,shallow overburden and deep water level of the main pier foundation for Muping Xiangjiang Specially Long Span Bridge,the PLC piles cofferdam is designed as the water retaining and retaining structure during foundation construction.Through the combination of steel sheet piles and steel pipe piles,the water stop effect of preliminary shaft is enhanced,the amount of steel is saved and the construction cost is reduced.Combined with the characteristics of formation lithology and low rock compressive strength,rotary drilling rig is selected to efficiently complete the cofferdam grooving construction.The groove quality is improved and the groove blind area is reduced by drilling with different diameters.Considering the characteristics that the moderately weathered argillaceous siltstone is easy to disintegrate and soften in case of water,the tank wall collapse is prevented by backfilling sand in the formed tank.In order to ensure the quality of bottom sealing,the air lift reverse circulation method is used for sand blasting construction of the cofferdam.The construction effect of the main pier foundation is good,which shows that PLC piles are suitable for deep water and shallow overburden stratum.
作者
杨金龙
曾华新
韩珂
YANG Jinlong;ZENG Huaxin;HAN Ke(CCCC Second Harbor Engineering Co.,Ltd.,Hubei 430040,China;Changsha Construction&Development Group Co.,Ltd.,Changsha,Hunan 410100,China)
出处
《施工技术（中英文）》
CAS
2022年第9期75-79,共5页
Construction Technology
基金
中交第二航务工程局有限公司科技研发项目:分幅式钢箱梁无托架顶推施工关键技术研究(EHYF-2021-B-05-037)。
关键词
桥梁
基础
围堰
PLC工法桩
有限元分析
施工技术
bridges
foundation
cofferdam
PLC piles
finite element analysis
construction
