摘要
针对某主跨为458m的分体式钝体双箱钢箱梁斜拉桥,通过缩尺比为1∶50的主梁节段模型风洞试验,研究桥梁的颤振和涡激共振性能。节段模型风洞试验结果表明,在0°和+3°两种风攻角下,该桥原始方案的颤振临界风速低于颤振检验风速,而且扭转涡激共振的振幅也超过了设计允许值。为了提高桥梁的颤振稳定性并抑制涡激共振,研究在分体式钝体双箱钢箱梁上游和下游两侧上方安装固定水平气动翼板的气动控制措施。气动翼板的宽度为0.043B(B:分体式钝体双箱钢箱梁的宽度),上游和下游两侧气动翼板质心之间的水平距离为1.02B,气动翼板质心至分体式钝体双箱钢箱梁顶面的竖向距离为0.45H(H:分体式钝体双箱钢箱梁的高度),两侧气动翼板单位长度的总质量为0.008meq(meq:单位长度分体式钝体双箱钢箱梁的等效质量)。节段模型风洞试验结果表明:安装固定水平气动翼板后,在0°和+3°两种风攻角下,该桥改进方案与原始方案相比颤振临界风速分别提高了24%和33%,均高于颤振检验风速,并且改进桥梁方案没有发生涡激共振现象。最后,通过分析不同风速下桥梁结构阻尼随风速的变化,结果发现:安装固定水平气动翼板后桥梁扭转运动的阻尼显著增加,从而提高了桥梁的颤振稳定性,同时有效抑制了桥梁的扭转涡激共振。
A series of 1∶50 scale sectional model wind tunnel tests were conducted to evaluate the flutter and vortex resonance performance of a cable-stayed bridge scheme with main span length of 458 m and separated bluff steel twin-box girder.The results of the sectional model wind tunnel tests show that at both 0° and +3° angle of attack cases for the original bridge scheme,the flutter critical wind speeds of the bridge are less than the flutter checking wind speed and that the amplitude peaks of torsional vortex resonance of the bridge exceed the design allowable value.In order to improve the aerodynamic stability and restrain the vortex resonance,a pair of stationary horizontal aerodynamic winglets installed on the leading and trailing edges of the separated bluff steel twin-box girder were studied by the above sectional model wind tunnel test.The width of the winglet is 0.043B(B:width of the twin-box girder),the horizontal distance between the center of mass of the two winglets is 1.02B,the vertical distance from the center of mass of the winglet to the top of the twin-box girder is 0.45H(H:height of the twin-box girder),and the mass per unit length of the two winglets is 0.008meq(meq:equivalent mass per unit length of the twin-box girder).Through the 1∶50 scale sectional model wind tunnel experiments of the separated bluff twin-box steel girder with stationary horizontal aerodynamic winglets,it is confirmed that at both 0° and +3° angle of attack cases for the improved bridge scheme,the flutter critical wind speeds increased by 24 and 33 percent compared with the corresponding cases of the original bridge scheme,respectively,and the lowest flutter critical wind speed are higher than the flutter checking wind speed,furthermore,the vortex shedding was not happened for the improved bridge scheme.Finally,based on the structural damping of the bridge with/without the stationary horizontal aerodynamic winglets at each wind speed of the sectional model wind tunnel experiments,it is found out that the torsional damping of the bridge increased greatly by installing stationary horizontal aerodynamic winglets,and thus both the aerodynamic stability and the torsional vortex shedding are effectively controlled.
出处
《土木工程学报》
EI
CSCD
北大核心
2010年第S2期49-54,共6页
China Civil Engineering Journal
基金
西部交通建设科技项目(200631849426)
国家863高技术研究发展计划课题(2007AA11Z101)
国家科技支持计划课题(2009BAG13A02)
关键词
斜拉桥
分体式钝体双箱钢箱梁
节段模型试验
固定水平气动翼板
颤振
涡激振动
阻尼
cable-stayed bridge
separated bluff steel twin-box girder
sectional model wind tunnel test
stationary horizontal aerodynamic winglets
flutter
vortex resonance
damping
