小宽高比钢桁架悬索桥颤振稳定气动措施的试验研究

以某主跨730m、宽高比小于4的钢桁架加劲梁悬索桥为研究对象，通过风洞试验考察了上中央稳定板、下中央稳定板、下横梁稳定板、导流板、双中央稳定板、双下稳定板等气动措施对主梁颤振临界风速的影响。结果表明：选取一定的尺寸（或角度），上中央稳定板能大幅提高0°和3°迎角下的颤振临界风速；下中央稳定板能大幅提高0°和-3°迎角下的颤振临界风速；下横梁稳定板对颤振临界风速的影响较小；主梁两侧栏杆上的稳定板能在一定程度上提高颤振临界风速；在桥面上下同时安装中央稳定板对于各个迎角均能大幅提高颤振临界风速；在下横梁上布置双稳定板，能在一定程度上提高0°和-3°迎角下的颤振临界风速，但同时降低3°迎角下的颤振临界风速。

Experimental study on aerodynamic measures for flutter stability of suspension bridge with small aspect ratio steel truss girder

Taking a suspension bridge with steel truss girder of which main span is 730m and aspect ratio is less than 4 as research object, effects of some aerodynamic measures on flutter critcal wind speed of main girder were investigated through wind tunnel tests. These aerodynamic measures include up-central stabilizing plate, down-central stabilizing plate, down-cross girder stabilizing plate, deflector, double-central stabilizing plate, double-down stabilizing plate. The experimental results show that up-central stabilizing plate with proper dimension can greatly increase flutter critical wind speeds at 0° and 3° angles of attack. Down-central stabilizing plate with proper dimension can greatly increase flutter critical wind speeds at 0° and -3°angles of attack. Down-cross girder stabilizing plate has little effect on flutter critical wind speed. Deflector in- stalled on handrails can increase flutter critical wind speed to a certain extent. Double-central sta bilizing plate can dramatically increase flutter critical wind speeds at all angles of attack. Doubledown stabilizing plate can slightly increase flutter critical wind speed at 0° and -3° angles of attack, but decrease flutter critical wind speed at 3° angle of attack at the same time.