桥面粗糙度对桥梁节段模型涡振试验结果的影响

摘要

目的 研究桥面粗糙度对大跨度桥梁节段模型涡振试验结果的影响,从而为涡振试验参数模拟提供依据.方法 采用节段模型风洞试验,研究不同桥面粗糙度下的涡振性能,并分析不同桥面粗糙度对随风速变化的涡振振幅的影响.结果 当实桥桥面粗糙度由0mm增加到16.5 mm时,开口断面主梁的竖弯和扭转涡振振幅在某度风攻角下分别降低了35.8％和24.8％,闭口断面主梁的扭转涡振振幅在某度风攻角下降低了43.0％,竖弯涡振现象则消失.结论 桥面粗糙度是影响主梁节段模型涡振试验结果的重要因素,精确地模拟桥面粗糙度是保证主梁节段模型涡振试验结果高精度不可忽视的因素,模型桥面粗糙度模拟得越低,涡振试验结果偏差越大.%This paper presents the research on the effect of bridge deck roughness on vortex-induced vibration tests results of the long-span bridges section model, which provides the basis for vortex-induced vibration test parameters simulation. Section model wind tests are carried out so as to identify the vortex-induced vibration performance of the stiffening girder with different deck roughness and the impact of different bridge deck roughness on the vortex-induced vibration amplitude changed with wind speed. The results of the tests show that when the bridge deck roughness increases from 0 mm to 16.5 mm,the vertical and torsional vortex-induced vibration amplitudes of the stiffening girder with opening crossing-section decrease 35. 8% and 24. 8% respectively at certain attack angles, while for the closed crossing-section stiffening girder,the torsional vortex-induced vibration amplitude decreases 43. 0% and the vertical vortex-induced vibration phenomenon disappears. At last,it is verified that deck roughness is an important factor affecting the vortex vibration tests results of stiffening girder section model. It can't be ignored that accurately simulating bridge deck roughness in order to ensure the section model vortex vibration test results of high accuracy. The lower the model deck roughness is simulated,the greater the deviation of the vortex vibration test results is.