分体式钢箱梁涡激振动控制试验

Investigation on the Vortex-Induced Vibration of a Twin Box Bridge Section

目的以分体式钢箱梁断面为研究对象,研究涡激振动控制措施,提出一新型的控制涡激振种动的格栅板形式.方法采用大尺度节段模型风洞试验,研究成桥状态该桥的涡激振动特性,并分析不同格栅板样式和空隙率对随风速变化的涡振振幅的影响.结果中央开槽断面的涡振性能较差,成桥状态涡振最大振幅达31.2 cm,加设50%空隙率格栅板后,涡振的振幅降低到10 cm以下.格栅板是一种有效的控制涡激振动的措施,格栅板的空隙率越小,抑制涡振的效果越好.结论空隙率相同时,顺桥向格栅和交叉格栅的抑振效果差不多,顺桥向格栅板抑制效果略好.

The vortex shedding response of a twin box bridge has been investigated with the objective of finding suitable method that can mitigate the vibration.A new grating that can mitigate the vibration is put forward.By means of wind tunnel test of a big scale sectional model,the mode of vortex excitation of the bridge is identified.Based on the result of the test,the mode and the penetration of the grating that will influence the mitigation efficiency are also studied.The test results indicate that a twin box bridge girder deck has a bad performance of vortex-induced vibration.However,the amplitude of the vibration decreased signifi-cantly from 32.1 cm to below 10cm after adding the grating.The grating is one of the effective methods to mitigate the vortex shedding.The smaller the void radio of the grating is,the better the grating can mitigate the vibration.When the void radio is the same,longitudinal and intersectant gratings have almost the same effect of mitigating the vortex shedding and the longitudinal grating is a little better.