湛江调顺跨海特大桥桥塔牌匾抗风性能研究  

Study of Wind Resistance of Signboards in Pylons of Tiaoshun Sea-Crossing Bridge in Zhanjiang

作　　者：郭文华 刘安兴 孙向东 张天翼 GUO Wen-hua;LIU An-xing;SUN Xiang-dong;ZHANG Tian-yi(Guangdong Communication Planning&Design Institute Group Co.,Ltd.,Guangzhou 510507,China;Research Center for Wind Engineering,Southwest Jiaotong University,Chengdu 610031,China)

机构地区：[1]广东省交通规划设计研究院集团股份有限公司,广东广州510507 [2]西南交通大学风工程试验研究中心,四川成都610031

出　　处：《世界桥梁》2021年第4期62-68,共7页World Bridges

基　　金：四川省科技计划资助项目(2020YJ0306);广东省交通规划设计研究院集团股份有限公司科技计划项目(粤交院[2021]研发YF-019)。

摘　　要：湛江调顺跨海特大桥主桥为(147.5+296+147.5)m钢箱组合梁斜拉桥,门形桥塔高136.916 m,塔顶设高约13 m装饰性牌匾,牌匾左、右侧各设置9道竖向装饰立柱。立柱为气动外形较钝的柔性结构,为确保桥塔牌匾在运营期的抗风安全性,首先采用有限元法分析牌匾的动力特性,然后进行缩尺比1∶10的牌匾气动弹性模型风洞试验,分析“H”形和矩形断面立柱在不同风偏角下的涡激振动和驰振性能。结果表明:“H”形断面立柱振动频率低,在常遇风速下发生了明显的涡激振动,立柱底部应力幅大,会影响牌匾抗疲劳性能;2种断面立柱均未发生驰振,与“H”形断面立柱相比,矩形断面立柱振动频率明显提高,在试验风速内虽然发生了涡激振动,但应力幅小,满足抗疲劳要求;优化后的矩形断面宽度由中部0.24 m渐变到端部0.35 m,一阶侧弯涡激振动起振风速提高至37.51 m/s,抗风安全性大幅提高,桥塔牌匾竖向装饰立柱采用优化后的矩形断面。The main bridge of Tiaoshun Sea-Crossing Bridge Zhanjiang is a steel box composite girder cable-stayed bridge with a main span of 296 m and two side spans of 147.5 m.The portal-framed pylons rise 136.916 m.A 13 m-tall decorative signboard is installed on the top of each pylon,and a number of 9 vertical decorative columns are arranged on both the left and right sides of the signboard.The columns are flexible structures of blunt aerodynamic shape.To guarantee the wind resistant safety of the signboards in the service period,the dynamic property of the signboards was first analyzed by finite element method,and then,a 1∶10 scale mockup of the signboard was prepared for the wind tunnel test.The vortex-induced vibration and galloping of the columns with H-shaped and rectangular cross-sections under different wind yaw angles were analyzed.The results show that the vibration frequencies of the columns with H-shaped cross-section were low,obvious vortex-induced vibrations were observed at regular wind speeds,the stress amplitude of the column base was big,which would influence the fatigue performance of the signboards.Neither the column with H-shaped cross-section nor the column with rectangular cross-section showed signs of galloping.Compared with the column with H-shaped cross-section,the vibration frequency of the column with rectangular cross-section was significantly improved,though vortex-induced vibration still existed within the testing wind speeds,but the stress amplitude was small,indicating it met the fatigue resistance requirements.After optimization,the width of the rectangular cross-section varies from 0.24 m at the center to 0.35 m at the ends.The critical wind speed that caused the first-mode lateral bending vortex-induced vibration was enhanced to 37.51 m/s,and the wind resistant safety of the signboards was greatly improved.The columns with optimized rectangular cross-section were finally chosen.

关 键 词：斜拉桥 桥塔牌匾 气动弹性模型 抗风性能 涡激振动 驰振 有限元法 风洞试验 

分 类 号：U448.27[建筑科学—桥梁与隧道工程] U443.38[交通运输工程—道路与铁道工程]