导流板对大跨桥梁风振响应影响的流场机理  

Flow Field Mechanism of Wind Induced Vibration Response of Large Span Bridge Influenced by Guide Vanes

作　　者：张伟[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：《中国公路学报》2009年第3期52-57,共6页China Journal of Highway and Transport

基　　金：国家高技术研究发展计划("八六三"计划)项目(2006AA11Z108);国家自然科学基金重点项目(50538050);国家自然科学基金项目(50608059)

摘　　要：为了分析导流板对桥梁风振响应的影响原理,在同济大学TJ-4风洞实验室,采用粒子图像测速系统(PIV)获得了丹麦大带东桥主桥断面在多种风速下的结构周围流场,并采用激光位移计记录了结构在相应风速下的位移响应,进而对流场进行了分析和比较。结果表明:在低风速下梁底存在旋涡,而导流板的设置能够消除旋涡;在高风速下,导流板不会对梁底的流场造成显著的改变,但会改变尾迹区旋涡的分布状态;结构稳定性即将丧失的重要特点是尾迹区正涡量旋涡对结构的支配性升力作用转变为正、负涡量旋涡对结构的交替性气动驱动作用。In order to analyze the mechanism of effects of the guide vane on the wind induced vibration response of large span bridge decks, using particle image velocimetry （PIV） system, two groups of experiments on Great Belt Bridge decks, including cases with and without guide vanes were carried out in TJ-4 wind tunnel lab. At the same time, the displacement responses of the deck were also obtained by laser displacement detector. The results show that there exist vortices with the low wind speed under the bridge deck. After the guide vanes are installed, no vortices can be found at the same place. In the cases of high wind speed, no obvious changes influenced by guide vanes are found under the bridge deck. However, the guide vane makes the vortices in downstream of the deck change a lot. The feature of mechanism for critical status is changing from the dominant lift action rooted in vortices with the vorticity being positive to the driving action rooted in both vortices with the vorticity being positive and negative.

关 键 词：桥梁工程 大跨桥梁风振 风洞试验 导流板 粒子图像测速 流场机理 

分 类 号：U446.1[建筑科学—桥梁与隧道工程]