斜风作用下桥塔对大跨度斜拉桥主梁静风荷载特性的影响  

Influence of Pylon on Static Wind Load Characteristics of Main Girder of Long-span Cable-stayed Bridge under Action of Oblique Wind

作　　者：曾加东 李明水[2] 张志田[1] 李少鹏 李志国[2] ZENG Jia-dong;LI Ming-shui;ZHANG Zhi-tian;LI Shao-peng;LI Zhi-guo(School of Civil Engineering and Architecture,Hainan University,Haikou Hainan 570228,China;Key Laboratory of Wind Engineering of Sichuan Province,Southwest Jiaotong University,Chengdu Sichuan 610031,China;School of Civil Engineering,Chongqing University,Chongqing 400045,China)

机构地区：[1]海南大学土木建筑工程学院,海南海口570228 [2]西南交通大学风工程四川省重点实验室,四川成都610031 [3]重庆大学土木工程学院,重庆400045

出　　处：《公路交通科技》2021年第11期52-58,共7页Journal of Highway and Transportation Research and Development

基　　金：国家自然科学基金项目(52068020,51938012);海南省自然科学基金项目(519QN191,520RC545)。

摘　　要：为有效评估斜风作用下桥塔对大跨度斜拉桥的干扰效应,及其对桥塔区域局部风环境和加劲梁静力风荷载特性的具体影响,以某730 m跨径斜拉桥为工程背景,采用自主设计的气动刚性模型测力系统、节段模型试验和CFD数值模拟计算相结合的研究方法,获得了某大跨度斜拉桥在不同来流风向下不同主梁位置处的流场分布和三分力系数结果。通过气动刚性模型测力系统测取斜风-桥塔工况下的主梁静力系数,可有效实现对斜风-桥塔联合干扰效应的研究,相比节段模型试验更符合实际情况。将气动刚性模型试验结果与节段模型、数值模拟及斜风分解理论计算结果进行对比,量化分析了斜风-桥塔联合干扰效应在评估斜拉桥主梁静力风荷载中的影响。结果表明:斜风作用下桥塔对其附近风场的干扰更为显著,存在较明显的风速放大或突降区,加劲梁在桥塔两侧的受扰区域宽度约为塔高的1/5;斜风-桥塔联合干扰作用对受扰区域内加劲梁静风荷载特性的影响不容忽视,可能导致主梁局部位置气动力较大幅度增大的不利情况;斜风分解法理论结果与气动刚性模型试验结果基本一致,但在斜风-桥塔联合干扰区域内可能得到偏不安全的结果,其适用性还有待于进一步完善。To accurately effectively evaluate the interference effect of bridge pylon on long-span cable-stayed bridge under the action of oblique wind,and its specific influence on the local wind field in the pylon area and the static wind load characteristics of the stiffening beam,taking a 730 m span cable-stayed bridge as the engineering background,by using the self-designed aerodynamic rigid model force measurement system,segment model test and CFD numerical simulation,the flow field distribution and three-component force coefficients of a long-span cable-stayed bridge at different positions of main girder under different incoming winds are obtained.The static coefficient of the main girder under the inclined wind-pylon condition can be measured by the aerodynamic rigid model force measurement system,it can effectively realize the research on the joint interference effect on inclined wind and bridge pylon,which is more in line with the actual situation than the segment model test.Through the comparison of aerodynamic stiffness model test result with the results of segment model,numerical simulation and theoretical calculation of oblique wind decomposition,the influence of the combined interference effect of the inclined wind-pylon on the evaluation of the static wind load of the main girder of the cable-stayed bridge is quantitatively analyzed.The result shows that(1)the interference of the pylon to the nearby wind field is more significant under the action of oblique wind,there is a more obvious wind speed acceleration or abrupt drop area,and the width of the disturbed area of the stiffening beam on both sides of the pylon is about 1/5 of the pylon height;(2)the influence of joint interference of the oblique wind-pylon on the static wind load characteristics of the stiffened beam in the disturbed area cannot be ignored,it may cause the disadvantage of a large increase in the aerodynamic force at the local position of main girder;(3)although the theoretical result of the oblique wind decomposition method is basically c

关 键 词：桥梁工程 斜风 测力试验 静风荷载 桥塔 

分 类 号：U441.2[建筑科学—桥梁与隧道工程]