宁波中兴大桥主桥钢梁架设关键技术

Key Erection Techniques for Steel Girder of Main Bridge of Ningbo Zhongxing Bridge

摘要:

宁波中兴大桥受建设条件限制，主桥设计为主跨400 m矮塔斜拉桥。主梁采用混合梁结构。钢梁架设采用“边跨梁段滑移+中跨梁段桥面吊机悬拼”的总体方案，设中跨合龙口。边跨梁段利用浮吊起吊，采用曲线滑移法就位安装；中跨有索区钢梁采用悬臂拼装，无索区钢梁扣索辅助悬拼；中跨合龙采用配切合龙法。实践结果表明：大桥梁段工业化生产与滑移、液压提升等架设技术的结合，有效保障了主梁结构整体性和施工安全性。

Abstract:

Subject to the constraints of the construction conditions, the main bridge of Ningbo Zhongxing Bridge is designed as a low-pylon cable-stayed bridge with main span of 400 m. The girder is a composite structural girder. The steel girder is erected by an overall scheme of “sliding of the side span beam segment + cantilever assembly of the middle span beam segment by crane on the bridge deck” with a mid-span closure joint. The side-span beam segments are hoisted by a floating crane and erected in place by the curved sliding method. For the mid-span, the steel girders in the cable area are assembled by cantilever, and the steel girder in the cable-free area is assisted in cantilever assembly with the use of clamps. The mid-span closure is achieved through the cut-to-fit method. Practical results demonstrate that the integration of industrialized production of bridge segments with the erection techniques such as sliding and hydraulic lifting effectively ensures the structural integrity and construction safety of the girders.