偏转风场下方形截面超高层建筑风致响应与气弹效应研究  

Investigation on wind-induced responses and aeroelastic effect of a square-sectional super high-rise building under twisted wind flow

作　　者：唐龙飞 刘昭 郑朝荣[3,4] 武岳[3,4] TANG Longfei;LIU Zhao;ZHENG Chaorong;WU Yue(School of Civil Engineering,Harbin Institute of Technology,Harbin 150090,China;China Construction Second Engineering Bureau Ltd.,Beijing 100071,China;Key Lab of Structures Dynamic Behavior and Control of the Ministry of Education,Harbin Institute of Technology,Harbin 150090,China;Key Lab of Smart Prevention and Mitigation of Civil Engineering Disasters of the Ministry of Industry and Information Technology,Harbin Institute of Technology,Harbin 150090,China)

机构地区：[1]哈尔滨工业大学土木工程学院,黑龙江哈尔滨150090 [2]中国建筑第二工程局有限公司,北京100071 [3]哈尔滨工业大学结构工程灾变与控制教育部重点实验室,黑龙江哈尔滨150090 [4]哈尔滨工业大学土木工程智能防灾减灾工业和信息化部重点实验室,黑龙江哈尔滨150090

出　　处：《建筑结构学报》2022年第12期20-30,共11页Journal of Building Structures

基　　金：黑龙江省自然科学基金资助项目(LH2019E050);中国建筑股份有限公司科研基金(CSCEC-2020-Z-58-2);国家自然科学基金项目(52078163)。

摘　　要：超高层建筑具有轻质高柔的特点,强风作用下其气弹效应明显;且水平风向角沿高度偏转,导致超高层建筑的风荷载和风致响应与不考虑风向偏转时有明显不同。为此,完成了风向偏转角为25°的偏转风场及其无偏等效风场下一方形截面千米级超高层建筑的气弹模型试验,基于试验所得的模型顶点加速度时程,结合Hilbert-Huang变换方法和改进的随机减量法识别了气动阻尼比,对比分析了风向角、折减风速和有无风向偏转对气动阻尼比、极值加速度、涡激共振临界风速和锁定区的影响规律,探究了偏转风作用下千米级超高层建筑的风致响应、气弹效应和涡激振动等特性。研究结果表明:风向角对气动阻尼比和极值加速度影响较大,会显著改变其变化规律和涡激共振临界风速;基于频域分析所得的涡激共振临界风速小于由气动阻尼比或极值加速度确定的涡激共振临界风速,表明后者所反映的涡激共振特性具有滞后性,将导致结构不安全;相比无偏等效风作用,偏转风作用下水平向气动阻尼比较大,结构的顶点极值加速度较小,角部极值加速度的最大降幅可达38.3%。The aeroelastic effect is very significant for super high-rise buildings under the action of strong winds, due to their lightweight nature and high flexibility. The angle of horizontal winds varies with the height, which leads to significant changes to the wind loads and wind-induced responses of super high-rise buildings. Therefore, aeroelastic model tests of a square-sectional thousand-meter-scale super high-rise building under twisted wind flow with a total wind twist angle of 25° and the equivalent straight wind flow were conducted in a boundary wind tunnel. Based on the experimental time history of the top acceleration of the aeroelastic model, the aerodynamic damping ratio was identified by using the Hilbert-Huang transform and the revised random decrement technique. The effects of the wind direction angle, reduced wind speed and wind twist angle on the aerodynamic damping ratio, extreme acceleration, critical wind speed of the wind-induced resonance and lock-in region were comparatively analyzed, and the characteristics of the wind-induced responses, aeroelastic effect and vortex-induced vibration of the thousand-meter-scale super high-rise building under twisted wind flow were investigated. The results show that, the effects of the wind direction angle on the aerodynamic damping ratio and extreme acceleration are very obvious, and it can significantly change the influencing law of these results and the critical wind speed of the wind-induced resonance. The critical wind speed based on the frequency analysis is less than that determined by the aerodynamic damping ratio or the extreme acceleration, suggesting that the vortex-induced resonance characteristic reflected by the latter two methods shows a wind speed lag and may lead to the unsafety of structures. Compared to those under straight wind flow, the horizontal aerodynamic damping ratios under twisted wind flow are larger and the extreme top acceleration is less. The maximum reduction of the extreme top corner acceleration can reach 38.3%.

关 键 词：超高层建筑 偏转风 气弹模型试验 风致响应 气动阻尼比 锁定区 

分 类 号：TU973.213[建筑科学—结构工程]