武汉杨泗港长江大桥猫道设计

武汉杨泗港长江大桥为主跨1700 m的单跨双层钢桁梁悬索桥,猫道采用三跨连续式无抗风缆猫道结构体系,猫道中跨跨度1700 m。猫道主要结构包括猫道承重索、门架支承索、扶手索、猫道面层、猫道门架系统、横向天桥、猫道索转向系统以及锚固调节系统等。猫道面宽4.0 m;猫道承重索由10根?56 mm钢丝绳组成,通过精轧螺纹钢筋和钢丝绳锚固于锚碇前锚面处;门架支承索由2根?54 mm钢丝绳组成,通过散索鞍支墩门架锚固于锚碇前锚面处;猫道索通过塔顶转向鞍座、下拉装置实现竖向转向,通过横向变位刚架实现水平转向。猫道结构静力计算结果表明:猫道索安全系数及静力抗风稳定性满足规范要求。

Catwalk Design of Yangsigang Changjiang River Bridge in Wuhan

The Yangsigang Changjiang River Bridge in Wuhan is a steel truss girder suspension bridge with a single span of 1700 m,accommodating two levels of decks.During the construction of the bridge,the three-span continuous catwalk system without wind cables was used.With central span of 1700 m,the catwalk consists of main components of load bearing cables,portal supporting cables,hand ropes,4.0 m-wide floor,portal frame system,transverse overpass,cable deviation system and anchorage adjusting system.The load bearing cable,which is composed of 10,?56 m steel wires,is anchored to the front anchor surface of anchorage of the suspension bridge via finish rolled screw steel bars and steel wire ropes.The portal supporting cable is formed of 2 steel wire ropes each containing 2,?54 mm steel wires,which is anchored to the front anchor surface of anchorage of the suspension bridge via supporting portal frame of the splay saddle.The load bearing cables of the catwalk could be vertically steered via the pylon-top deviation saddle and downward pulling device and transversely steered via the transverse rigid deviation frame.The static calculation results of the catwalk structure indicate that the safety factor and static wind resistance of the load bearing cables could meet the code requirements.