双开槽箱梁断面悬索桥的抗风性能及气动措施研究  

Wind resistance performance of a double-slotting suspension bridge and its aerodynamic control measures

作　　者：夏锦林 曹丰产[1] 葛耀君[1] 

机构地区：[1]同济大学土木工程防灾国家重点实验室,上海200092

出　　处：《振动与冲击》2017年第10期69-75,共7页Journal of Vibration and Shock

基　　金：土木工程防灾国家重点实验室"973计划"项目(2013CB036301)

摘　　要：为研究双开槽箱梁断面桥梁的抗风性能,并提出合理的颤振和涡振气动控制措施,本文以拟建的某钢箱梁悬索桥为研究对象,开展了一系列节段模型风洞试验,并结合二维三自由度方法和CFD数值模拟分别分析了不同措施下颤振和涡振机理的改变。研究表明:相比于单箱梁断面,双开槽断面能有效的改善颤振性能;防撞栏杆基座的有无,对该类桥的颤振临界风速影响显著;中央稳定板作为改善颤振稳定性的常用手段,对提高双开槽断面颤振临界风速同样适用,且在一定范围内,临界风速与稳定板高度正相关;二维三自由度分析结果显示,中央稳定板和较优形式的栏杆均能减缓气动阻尼随风速的变化趋势。针对开槽引起涡振的问题,尝试采用各种控制措施,试验证明,均匀间隔的纵向格栅能有效的抑制涡振。结合CFD模拟,其根本原因为纵向格栅明显改变了流场绕流特性,阻碍了大规模涡脱的形成。To understand the flutter and vortex-induced vibration(VIV) performance of the bridge deck with double-slot and to propose feasible control measures,a sectional wind tunnel test was carried out on a steel-box suspension bridge being planned.An analysis based on a 2 dimension-3DOF(2D-3DOF) model and a CFD simulation were introduced respectively to understand the flutter and VIV mechanisms.The results show that,the double-slotting is an effective method to improve the flutter performance of the steel-box deck.The type of railings,i.e.,with or without pedestal,influences the critical wind speed significantly.Besides,the central stabilizer,as a conventional control alternative,also has a positive impact on the bridge's stability.In a certain range,the height of the stabilizing plate has positive correlation with the stability.As shown by the 2D-3DOF method,both the central stabilizer and optimized railing can slow down the changing tendency of aerodynamic damping with the changing of wind speed.Since the VIV often occurs on a slotting deck,various measures have been taken into account in the test,while the equidistant grating is proved to be more efficacious.By the CFD simulation,it is found,the essential mechanism is that the grating changes the flow field notably so as to avoid the large-scale vortex shedding.

关 键 词：双开槽箱梁 颤振 气动措施 风洞试验 

分 类 号：U441.3[建筑科学—桥梁与隧道工程] V211.7[交通运输工程—道路与铁道工程]