沪通长江大桥天生港专用航道桥主桁关键节点制造技术

Manufacturing Techniques for Key Main Truss Panel Points for Tianshenggang Navigational Channel Bridge of Hutong Changjiang River Bridge

沪通长江大桥天生港专用航道桥为(140+336+140)m钢桁拱桥,其中主墩支座处的加劲弦节点杆件为Q500qE钢,采用栓焊结合的整体节点构造,结构形式和连接关系复杂、焊缝密集,制造难度大。制造过程中,采用"正装法"解决了复杂结构的空间几何关系精度控制和磨光顶紧难题;试验比选确定了不同部位合理的焊接工艺,解决了新材料Q500qE钢焊接难题;通过预变形、自约束、它约束相结合的技术措施,实现了对焊接变形的有效控制;采用大型数控钻床制孔工艺,确保了孔群的空间关系精度;采用大型落地镗床均温加工方法,确保了超大底板平面度的高精度要求。

The Tianshenggang Navigational Channel Bridge is a steel truss arch bridge with span arrangement of 140 m+336 m+140 m.The members of the stiffening chord panel point at the bearings of main piers are made of Q500qE steel,creating an integral panel point structure formed by the combined use of bolting and welding.The structure poses great challenges to manufacture,due to its complex structural form and connecting relations as well as the densely distributed welds.During the manufacturing process,the way of installation in regular order was adopted aiming to overcome the difficulties in accuracy control of the spatial and geometrical relation of the complex structure as well as resolving the finishing and tightening problems.By the comparison of different tests,the rational welding techniques for different structural parts were determined and the welding of the Q500qE steel was resolved.The effective control of the deformation of butt joint was realized via the combination of pre-deformation,self constraint and external constraint.The large numerical control drilling machine was used to drill holes,with the intension of ensuring the spatial relation accuracy of the hole groups.The large floor boring machine was used to the constant temperature manufacturing,to ensure the high accuracy demand of the flatness of the over large base plate.