摘要
双幅钢箱梁桥是工程实践中一种常用的大跨度连续梁桥型式,但并列双箱复杂的旋涡脱落和交互作用可能引发显著的涡激振动现象,影响结构的疲劳性能和行车舒适性。本文以某六边形双幅钢箱连续梁桥为工程背景,对大比例节段模型开展了测振、测压风洞试验,对比了双幅钢箱梁在不同间距下竖弯涡振全过程(涡振前、上升区、振幅极值点、下降区及涡振结束)的分布气动力演变特点,提出了有效控制双幅钢箱梁桥涡振的气动措施。研究表明,双幅钢箱梁桥涡振锁定区间长、振幅大,+3°为最不利攻角,涡激力的倍频效应与间距和双幅箱梁涡振的振幅均有关。在小间距及低风速时,上、下游梁背风侧的分布气动力对涡激振动起到增强作用;在大间距或较小间距且高风速时,开槽附近上表面和下游梁斜腹板位置的分布气动力对涡激力起主要增强作用,也是双幅钢箱梁产生大幅涡激振动的诱因。提出了槽间裙板与两端风嘴组合的综合气动控制措施,通过切断槽间涡的传播途径从而降低桥面处分布气动力对涡激力的贡献,该措施可有效减弱双幅钢箱梁桥的竖弯涡振。
The long-span continuous beam bridge with parallel twin steel box decks is common in engineering practice,but the complex vortex shedding and interaction of parallel twin steel box girders may cause significant vortex-induced vibration(VIV),af⁃fecting the fatigue performance of the structure,driving comfort,and possibly causing social panic.This paper takes parallel twin box girders as the research background,and a large-scale segment model vibration and pressure measurement wind tunnel test is carried out.The evolution characteristics of the distributed aerodynamic force in the entire vertical bending vortex vibration process(before the vortex vibration,the ascending zone,the amplitude extreme point,the descending zone,and the end of the vortex vi⁃bration)under different spacings are compared,and effective aerodynamic measures to control the vortex vibration of the parallel twin box girders are proposed.The study shows that the vortex-induced vibration lock-in regime of the parallel twin steel box gird⁃ers is long,the amplitude is large,+3°is the most unfavorable angle of attack(AOA)and the frequency multiplication effect of the vortex excitation force is related to the amplitude and the spacing between the box girders.When the spacing makes the interslot vortex fully developed,it significantly increases the pulsation of the aerodynamic force distributed near the slot.In the case of small spacing and low wind speed,the distributed aerodynamic force on the lee side of the upstream and downstream girders en⁃hances the vortex-induced vibration.At large or small spacing with high wind speed,the distributed aerodynamic force on the upper surface near the slot and the position of the inclined web of the downstream girder plays a major role in enhancing the vortex-in⁃duced force,which is the inducement of the large amplitude of vortex-induced vibration of the parallel twin box girders.A compre⁃hensive aerodynamic control measure of setting the apron between the slots and setting the wind fairing at both en
作者
徐胜乙
方根深
赵林
宋神友
葛耀君
XU Sheng-yi;FANG Gen-shen;ZHAO Lin;SONG Shen-you;GE Yao-jun(State Key Laboratory of Disaster Reduction in Civil Engineering,Tongji University,Shanghai 200092,China;Key Laboratory of Transport Industry of Wind Resistant Technology for Bridge Structures,Tongji University,Shanghai 200092,China;Shenzhen-Zhongshan Passageway Management Centre,Zhongshan 528400,China)
出处
《振动工程学报》
EI
CSCD
北大核心
2024年第7期1139-1150,共12页
Journal of Vibration Engineering
基金
国家自然科学基金资助项目(52108469,52278520)
中国科协青年人才托举工程资助项目(2023QNRC001)
上海市教育委员会晨光计划资助项目(22CGA21)
中央高校基本科研业务费专项资金资助项目(22120220577)。
关键词
桥梁抗风
双幅钢箱梁
涡激振动
风洞试验
分布气动力
气动措施
wind resistance of bridge
parallel twin steel box girders
vortex-induced vibration
wind tunnel test
distributed aerodynamic force
aerodynamic measures
