珠江入海口超深淤泥层大型围堰设计与施工  

Design and Construction of Large Cofferdam in Deep Silty Soils at Pearl River Estuary

作　　者：周平 ZHOU Ping(Shenjiang Command Center of Xiamen Shenzhen Railway Guangdong Co.,Ltd.,Jiangmen 529000,China)

机构地区：[1]厦深铁路广东有限公司深江指挥部,广东江门529000

出　　处：《世界桥梁》2025年第1期29-34,共6页World Bridges

摘　　要：深江铁路洪奇沥水道公铁大桥主桥为主跨808 m的双塔双索面混凝土-钢箱桁混合组合梁斜拉桥。49号桥塔基础位于珠江入海口超深流塑状淤泥层地带,围堰最大开挖深度超过14 m,开挖方量达3.6万方。该围堰采用“锁口钢管桩围堰+干挖法施工”的工艺,围堰平面尺寸59.92 m×43.87 m,总高33 m,锁口钢管桩采用∅820 mm×14 mm钢管焊接而成,围堰内设3层内支撑,采用CT锁扣形式;计算结果显示围堰变形、应力、嵌固深度、抗倾覆和坑底抗隆起的验算结果均满足要求。施工过程中,锁口钢管桩现场接长,采用DZ180振动锤由围堰上游角桩开始分2个方向插打至下游对角管桩处合龙;围堰基坑采取快速干挖施工,随基坑开挖深度增加逐层整体下放安装圈梁并依次安装内支撑;采用围堰智能监测平台,对关键指标数据进行自动采集。采用以上技术实现了超深淤泥层大型锁口钢管桩围堰的干挖施工,大幅提高了工效,同时减少了泥浆污染。The main bridge of Hongqili Waterway Rail-cum-Road Bridge carrying a section of the Shenzhen-Jiangmen Railway is a two-pylon cable-stayed bridge with a main span of 808 m.The superstructure is a hybrid structure of concrete panels,steel box girders and steel trusses.The foundation of the pylon No.49 stands in the deep flow plastic silty soils at the Pearl River estuary,where the maximum excavation depth of the cofferdam exceeded 14 m and the excavation volume reached 36000 m 3.The cofferdam,measuring 59.92 m by 43.87 m by 33 m(height),consists of interlocking steel pipe piles(∅820 mm×14 mm,CT clamps),and the foundation pit was excavated in dry condition,inside which,three layers of inner supports are installed.The calculations demonstrate that the parameters of the cofferdam,including deformation,stresses,embedding depth,anti-overturning performance,and the pit-bottom anti-humping performance,met the requirements.During the construction,the interlocking steel pipe piles were prolonged on site,and driven one by one by the DZ180 vibration hammers,starting from the upstream corner piles,progressing towards two directions and being closed at the downstream diagonal corner piles.The foundation pit was excavated by a rapid dry excavation method,as the excavation depth increases,the ring beams were integrally installed layer by layer,and followed the installation the layer-by-layer installation of inner supports.An intelligent monitoring platform was built up to automatically collect the key data.The construction efficiency of the cofferdam was greatly improved while keeping the slurry pollution under control.

关 键 词：斜拉桥 超深淤泥层 锁口钢管桩围堰 干挖法 结构设计 施工技术 

分 类 号：U448.27[建筑科学—桥梁与隧道工程] U443.162[交通运输工程—道路与铁道工程]