武汉杨泗港长江大桥主桥施工关键技术  

Key Construction Techniques for Main Bridge of Yangsigang Changjiang River Bridge in Wuhan

作　　者：李兴华[1,2] 潘东发 LI Xing-hua;PAN Dong-fa(China Railway Major Bridge Engineering Group Co.,Ltd.,Wuhan 430050,China;State Key Laboratory for Health and Safety of Bridge Structures,Wuhan 430034,China)

机构地区：[1]中国中铁大桥局集团有限公司,湖北武汉430050 [2]桥梁结构健康与安全国家重点实验室,湖北武汉430034

出　　处：《桥梁建设》2020年第4期9-16,共8页Bridge Construction

基　　金：中国中铁股份有限公司科技开发计划项目(2015-重大-06-01)。

摘　　要：武汉杨泗港长江大桥主桥为主跨1700 m的单跨双层钢桁梁悬索桥。该桥2个桥塔均采用沉井基础,沉井下部为钢壳混凝土结构,上部为钢筋混凝土结构;锚碇采用外径98 m、壁厚1.5 m的圆形地下连续墙基础;桥塔为钢筋混凝土门式结构,1号和2号塔高分别为231.9 m和243.9 m,采用C60高性能混凝土浇筑;主缆采用直径6.2 mm、标准抗拉强度1960 MPa的锌铝合金镀层高强钢丝;加劲梁采用华伦式桁架全焊接结构。在该桥施工中,沉井隔舱区域硬塑黏土层采用搅吸机+高压射水取土的工艺施工,刃脚盲区采用爆破+斜向弯头吸泥机取土的工艺施工;地下连续墙采用液压成槽机和双轮铣槽机进行槽段成槽施工,内衬及填芯混凝土采用逆作法施工;桥塔采用液压爬模施工,通过优化混凝土配合比、选择高压输送泵将C60混凝土一泵到顶;主缆钢丝为国产新材料,按4个阶段组织生产;主缆采用索股混编,PPWS法架设,利用双线往复式牵引系统进行索股牵引;加劲梁采用整体节段制造、吊装技术施工,钢梁节段采用缆载吊机从跨中向桥塔方向逐段吊装。The main bridge of Yangsigang Changjiang River Bridge in Wuhan,which is a steel truss girder suspension bridge,has a single main span of 1 700 mand two layers of highway decks.The two towers are all supported by caisson foundations that comprise the lower steel shellconcrete structures and the upper reinforced concrete structures.Each anchor block is mounted on the circular diaphragm wall foundation with an external diameter of 98 mand wall thickness of 1.5 m.The towers,named towers No.1 and No.2,are reinforced concrete portal structures made of C60 high-strength concrete,measuring 231.9 ma nd 243.9 m in height,respectively.The main cables are formed of φ6.2 mm Zn-Al coated high-strength steel wires,with nominal tensile strength of 1 960 MPa.The stiffening girder is composed of fully-welded Warren trusses.During the construction process,the hard plastic clay in the chambers of the caisson was excavated and dredged using a cutter suction dredger and high-pressure water shooting method,while the clay under the cutting edges were treated by blasting and using the suction dredger with dredge swivel bend for soil discharge.Trenches for the diaphragm walls were dug and took form by using hydraulic tren-ching machine and two-wheel milling machine,with the linings and core concrete filled by top-down method.The towers were constructed by hydraulic climbing formwork,after optimization of the mixing proportion,the C60 concrete could be delivered to the top of the pylon by high-pressure pump with a one-off operation.The steel wires of the main cables are made of new domestic materials,manufactured in four stages.A main cable contains steel wires from two enterprises,erected by PPWS method,using a double-track to-and-from traction system.The stiffening girders were assembled from integral segments manufactured in the factory and hoisted into position at the bridge site,with the erection of segments one by one proceeding from the midspan towards the two towers using cable cranes.

关 键 词：悬索桥 沉井基础 锚碇基础 地下连续墙 高性能混凝土 主缆钢丝 钢桁梁 施工技术 

分 类 号：U448.25[建筑科学—桥梁与隧道工程] U445.4[交通运输工程—道路与铁道工程]