摘要
湖北燕矶长江大桥为主跨1860 m的内外缆不同垂度四主缆体系双层钢桁梁悬索桥,具有高低四缆、双缆窄距、小垂跨比、超大跨度、并联索鞍等特点,该桥猫道横向布置困难、索力大、布索空间小、过塔困难、抗风复杂。针对上述问题,提出一种三跨连续式非对称猫道设计方案。猫道采用等宽非对称断面布置,保证猫道面层、天桥施工效率的同时解决了双缆窄距带来的猫道横向布置难题;猫道承重索采用Φ60 mm标准抗拉强度2160 MPa高强度钢丝绳,减少承重索数量,结合双层承重索受力体系,有效解决了索力大及布索空间小的难题;猫道承重索采用穿塔方案,消除了并联索鞍带来的过塔难题;内、外缆猫道之间设置横向阻尼抗风装置及制振索,大幅降低了内、外缆猫道之间碰撞风险,提升了猫道使用的安全性与舒适性。
The Yanji Changjiang River Bridge in Hubei Province is a suspension bridge with a main span of 1860 m,featuring the steel truss superstructure accommodating two levels of decks as well as the four main cables,where the sag ratio of the two outer main cables is different from that of the two inner main cables.Multiple characteristics of the bridge limit the installation of the catwalks and demand large cable tensions,however,the space for main cable installation is small,the catwalk is difficult to pass through the towers,and the wind environments on the bridge are complex.A three-continuous-span asymmetric catwalk design was proposed.The catwalk is characterized by the constant-width asymmetric cross-section,ensuring the installation efficiency of the floor beams of the catwalk and the elevated trestle,as well as facilitating the transverse distribution of the catwalks,as the narrow spacing between the main cables imposed challenges for the installation of the catwalks.The load-bearing ropes of the catwalks consist of∅60 mm high-strength steel wires with a standard tensile strength of 2160 MPa,so as to reduce the number of load bearing ropes,together with the load bearing system of the two layers of load bearing ropes,to lower the main cable tension and facilitate the erection of main cables in a limited space.The load bearing cables of the catwalk were threaded through the tower,to ease the challenges imposed by the tandem saddles.Between the catwalks suspended by the inner and outer main cables,transverse damping wind-resistant devices and vibration suppressing cables were installed,to significantly reduce the collision risk of the catwalks suspended by the inner and outer main cables,and improve the traveling safety and comfort of the catwalk.
作者
赵全成
张栋
蒋本俊
ZHAO Quancheng;ZHANG Dong;JIANG Benjun(China Railway Major Bridge Engineering Group Co.,Ltd.,Wuhan 430050,China)
出处
《桥梁建设》
北大核心
2025年第4期10-17,共8页
Bridge Construction
基金
中国中铁股份有限公司科技研究开发计划课题(2022-专项-03)。
关键词
悬索桥
不同垂度四主缆
猫道
等宽非对称断面
双层承重索
穿塔方案
抗风措施
结构设计
suspension bridge
four main cables with different sag ratio
catwalk
constant-width asymmetric cross-section
double-layer load bearing cable
passing through tower
wind resistant measure
structural design
