虎门二桥坭洲水道桥钢箱梁架设关键技术分析

Analysis of Key Technologies for Erection of Steel Box Girder of Humen Second Bridge Nizhou Waterway Bridge

坭洲水道桥是虎门二桥工程两座超千米级悬索桥之一,为不对称双塔双跨连续钢箱梁悬索桥体系。全桥钢箱梁分11个类型,合计176片,吊装总重量达到4.7万t。结合主跨区、浅水区、近塔无索区及合拢段的水文地质条件、水深情况、航道关系等环境限制因素有针对性的采用跨缆吊机、可伸缩活动托架移梁、荡移法等关键技术进行钢箱梁的架设。通过新设备、新技术、新工艺等研发创新,在优化施工组织、特殊梁段专项管控、监控测量动态纠偏、各参与方高效协同的共同努力下,最大程度减小了吊梁过程中的海上交通、台风暴雨、潮汐水深、运梁定位等诸多不利因素综合影响,实现了70 d内完成全部176片钢箱梁的架梁任务,对类似工程具有一定的参考借鉴意义。

Nizhou Waterway Bridge is the longer suspension bridge of Second Humen Bridge Project,which consists of 2 suspension bridges with over 1000 m spans and expressway.The asymmetrical span arrangement of this two-pylon double-span continuous steel box.The total 176 pieces steel box girders with 47000 tons total lifting weight include 11 types.In terms of the hydrological and geological conditions,water depth,river channel and other environmental constraints in the main span area,shoal water area,cable-free area closed to pylon and the closure area,specific and targeted construction methods such as lifting with erection gantry,slipping beam with telescopic and movable bracket,swing lifting method are applied to erect the steel box girders.Through research and innovation of new equipment,new technologies,and new processes,also optimization of lifting construction organization,targeted control of specific beam segments,dynamic rectification of deviation with measurement and monitoring,the efficient and joint efforts of all parties,many disadvantageous affects including channel traffic,typhoon storm,tide and water depth,transport and position will be minimized.As a result,the erection task of 176 steel box girder segements was completed within 70 days,which can be a reference for similar projects.