大跨度三塔斜拉桥超长加劲平行斜拉索气弹模型风洞试验研究  

Wind Tunnel Test of Aeroelastic Model of Super-long Stiffening Parallel Stay Cables of Long-span Three-pylon Cable-stayed Bridge

作　　者：陈强 华旭刚[2] 冯丛 陈野 张艳梅 CHEN Qiang;HUA Xugang;FENG Cong;CHEN Ye;ZHANG Yanmei(Department of Science and Technology Information,Haolebaoji-Ji’an Railway Co Ltd,Beijing 100073,China;School of Civil Engineering,Hunan University,Changsha Hunan 410082,China;Department of Engineering Management,Haolebaoji-Ji’an Railway Co Ltd,Beijing 100073,China)

机构地区：[1]浩吉铁路股份有限公司科技信息部,北京100073 [2]湖南大学土木工程学院,湖南长沙410082 [3]浩吉铁路股份有限公司工程管理部,北京100073

出　　处：《中国铁路》2021年第9期110-117,共8页China Railway

基　　金：中国国家铁路集团有限公司科技研究开发计划项目(2003G001-B)。

摘　　要：为增加洞庭湖大桥(三塔斜拉桥)的中塔刚度,采用4组超长平行加劲斜拉索连接中塔顶部和边塔桥面中横梁部位。根据桥址处风场特性,结合超长加劲斜拉索的基本参数,分析超长加劲斜拉索的尾流驰振检验风速及风雨振制振最小阻尼比(不小于3.8%)。设计制作1∶60缩尺模型,分别对模型索和实桥索开展非线性有限元计算及动力特性参数测试,结果证明二者相似性良好。超长加劲斜拉索尾流驰振风洞试验结果表明,在-25°~25°风攻角时,超长加劲平行斜拉索的下游拉索均发生大幅度尾流驰振现象,且尾流驰振发生风速(最低为29.0 m/s)均低于相应的驰振检验风速(51.3 m/s)。为消除超长加劲斜拉索尾流驰振效应,除采用螺纹状拉索表面、设置外阻尼器使各拉索3 Hz以下模态的阻尼比大于0.4%(按Scruton数大于10的准则)外,尚需辅助安装一定数量刚性或柔性分割器以消除尾流驰振效应。气弹模型制振风洞试验表明,当1组加劲平行索的2根拉索(上、下游各1根)之间设置3道分隔器(刚性或柔性)时,下游超长加劲斜拉索在检验风速内均未观察到尾流驰振现象。基于风洞试验成果及时完善超长斜拉索的制振措施设计,增设3个刚性分隔器,有效消除了加劲斜拉索的尾流驰振效应。经过1年8个月各种环境下的安全运营,有效验证了刚性分割器措施的有效性。In order to increase the stiffness of the middle pylon of Dongting Lake three-pylon cable-stayed bridge,four sets of super-long stiffening parallel stay cables were used to connect the top of the middle tower and the middle beam of the side tower deck.In line with the wind field characteristics at the bridge site and the basic parameters of the superlong stiffening stayed cable,the test wind speed of the wake galloping and the minimum damping ratio(not less than 3.8%)of wind-rain induced vibration of the super-long stiffening stay cable were analysed.A 1∶60 scale model was designed and produced,and the nonlinear finite element calculation and dynamic characteristic parameter test of the model cable and the real bridge cable were carried out respectively,whose results showed the high similarity.The wind tunnel test results of wake galloping of super-long stiffening stay cables showed that the downstream cables of superlong stiffening parallel stay cables had a large wake galloping at an inclination angle-25°~25°of winds,and the wind speed of wake galloping(minimum 29.0 m/s)was lower than the corresponding wind speed(51.3 m/s)of galloping test.In order to eliminate the wake galloping effect of super-long stiffening stay cables,in addition to adopting threaded cable surfaces and setting external dampers to make the damping ratio of modes below 3 Hz of each stay cable greater than 0.4%(according to the criterion that the Scruton number was greater than 10),a certain number of rigid or flexible separators needed to be installed to eliminate the wake galloping effect.The wind tunnel test with vibration generated in aeroelastic model showed that when three separators(rigid or flexible)were set between two cables(one for upstream and downstream each)of a group of stiffening parallel cables,wake galloping was not observed in the test wind speed of the downstream super-long stiffening stay cables.Based on the wind tunnel test results,the design of vibration control measures for super-long stay cables was improved in ti

关 键 词：超长加劲斜拉索 尾流驰振 风洞试验 有限元分析 制振措施 

分 类 号：U446[建筑科学—桥梁与隧道工程]