广州西塔风致响应和气弹效应的试验研究
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摘要
随着社会的发展、科学技术的进步和城市化进程的加快,高层、超高层建筑得到了迅猛地发展。由使用新材料、新工艺和新的施工技术建造起来的超高层建筑通常是轻质高柔性结构,这类建筑对于风环境特别敏感,风荷载已成为超高层建筑的重要控制荷载。
大量实验表明,超高层建筑的横风向动力响应通常要比顺风向的大。在工程应用中,横风向的等效静态风荷载有时甚至起到了决定性的作用。对一些高柔轻质建筑而言,其结构与风之间的相互作用,有时会使结构响应急剧放大而导致结构不稳定乃至破坏,影响结构使用和安全。因此,需要对此类结构进行气动弹性效应影响的研究。
在建的432m广州珠江新城西塔为典型的高柔性结构,本文以此为原型,设计制作了气动弹性模型,考察这一重要工程结构的气动弹性效应。首先通过静力拉伸法测量并估算结构阻尼,发现了模型结构阻尼随响应振幅的增加而增加的规律。通过一系列风洞试验,运用随机减量技术(RDT)识别出了结构的动力响应参数,分析了结构的气动阻尼特性。结果表明:西塔的横风向气动阻尼基本上均为正数,在低风速段随风速的增加而增加,在梯度风风速为45.4m/s时达到最大值为1.75%;随后在临界风速附近急剧下降,在51m/s时降到最小值,约为-0.06%。由于负气动阻尼值的绝对值很小,可以忽略其不利影响。最后在总阻尼识别的基础上,将气弹模型的结果和刚性模型的结果进行了比较,结果显示,两种不同试验方法的结果具有较好的可比性。
同时根据高层建筑结构振动控制原理,设计了倒悬质量块的减振装置(TMD)。通过可调质量块来改变减振装置的参数,使其达到较好的减振结果。结果发现:减振参数的选取对减振效果起着重要的作用,减振装置会使结构的固有特性发生改变,而这又会反过来影响结构的减振效果。
本文实施的气动弹性模型试验,部分验证了刚性模型试验的可靠性。气弹模型试验得到的气动阻尼特性可以作为西塔结构抗风设计的依据,也可为相关工程提供参考。
Modern super tall buildings are usually constructed with innovative structural systems and high strength materials; tend to be more flexible and lightly damped than those in the past. As a consequence, the sensitivity of these buildings to strong wind has increased. Wind load plays the key role in the structural design of those buildings.
Massive experiments indicate that wind induced response on super tall buildings in the crosswind direction may be more significant than that in the along-wind direction. For high flexible buildings, the effect of the interaction between the structure and wind on wind induced response and wind loads may also significant. Aerodynamic damping that reflects the effect of the structure-wind interaction often plays an important role in estimations of wind induced dynamic responses of super high-rise buildings. Aero-elastic model test is considered to be the most reliable method for evaluating wind effects on super tall buildings.
Guangzhou West Tower (GWT) with a height of 432m is at present the tallest building in south China. In first part of this study, in order to evaluate the aeroelastic effect, an experiment of GWT is firstly carried out using the MDOF aero-elastic model technique in boundary layer wind tunnel. and the results are compared with those of stiffness model based experiment using the high frequency base balance (HFBB) technique. The Random Decrement Technology (RDT) is applied to identify the aerodynamic damping of GWT. Good agreement in wind-induced response is found between the two techniques when same damping ratio is used to calculate the wind induced response in the HFBB approach. Generally, the aerodynamic damping of GWT is positive at large scope of wind speed. The results show that the aerodynamic damping increase with the increase of the wind speed and a maximum aerodynamic damping of 1.74% is found when the wind speed at the gradient wind height is 45.4m/s. Then the aerodynamic damping decrease rapidly near the critical wind speed, and finally a minimum aerodynamic damping of–0.06% is found at wind speed of 51m/s.
In part 2, a tuned mass damper (TMD) is applied to reduce the wind-induced vibration of GWT. Wind tunnel experiments are performed to verify the effectiveness of TMD on reducing the wind-induced vibration on super tall building model. The effects of the introduction of a TMD on the vibration of the building model of GWT are analyzed and discussed.
Finally, some conclusions are summarized as the reference for the wind-resistant design of GWT.
大量实验表明,超高层建筑的横风向动力响应通常要比顺风向的大。在工程应用中,横风向的等效静态风荷载有时甚至起到了决定性的作用。对一些高柔轻质建筑而言,其结构与风之间的相互作用,有时会使结构响应急剧放大而导致结构不稳定乃至破坏,影响结构使用和安全。因此,需要对此类结构进行气动弹性效应影响的研究。
在建的432m广州珠江新城西塔为典型的高柔性结构,本文以此为原型,设计制作了气动弹性模型,考察这一重要工程结构的气动弹性效应。首先通过静力拉伸法测量并估算结构阻尼,发现了模型结构阻尼随响应振幅的增加而增加的规律。通过一系列风洞试验,运用随机减量技术(RDT)识别出了结构的动力响应参数,分析了结构的气动阻尼特性。结果表明:西塔的横风向气动阻尼基本上均为正数,在低风速段随风速的增加而增加,在梯度风风速为45.4m/s时达到最大值为1.75%;随后在临界风速附近急剧下降,在51m/s时降到最小值,约为-0.06%。由于负气动阻尼值的绝对值很小,可以忽略其不利影响。最后在总阻尼识别的基础上,将气弹模型的结果和刚性模型的结果进行了比较,结果显示,两种不同试验方法的结果具有较好的可比性。
同时根据高层建筑结构振动控制原理,设计了倒悬质量块的减振装置(TMD)。通过可调质量块来改变减振装置的参数,使其达到较好的减振结果。结果发现:减振参数的选取对减振效果起着重要的作用,减振装置会使结构的固有特性发生改变,而这又会反过来影响结构的减振效果。
本文实施的气动弹性模型试验,部分验证了刚性模型试验的可靠性。气弹模型试验得到的气动阻尼特性可以作为西塔结构抗风设计的依据,也可为相关工程提供参考。
Modern super tall buildings are usually constructed with innovative structural systems and high strength materials; tend to be more flexible and lightly damped than those in the past. As a consequence, the sensitivity of these buildings to strong wind has increased. Wind load plays the key role in the structural design of those buildings.
Massive experiments indicate that wind induced response on super tall buildings in the crosswind direction may be more significant than that in the along-wind direction. For high flexible buildings, the effect of the interaction between the structure and wind on wind induced response and wind loads may also significant. Aerodynamic damping that reflects the effect of the structure-wind interaction often plays an important role in estimations of wind induced dynamic responses of super high-rise buildings. Aero-elastic model test is considered to be the most reliable method for evaluating wind effects on super tall buildings.
Guangzhou West Tower (GWT) with a height of 432m is at present the tallest building in south China. In first part of this study, in order to evaluate the aeroelastic effect, an experiment of GWT is firstly carried out using the MDOF aero-elastic model technique in boundary layer wind tunnel. and the results are compared with those of stiffness model based experiment using the high frequency base balance (HFBB) technique. The Random Decrement Technology (RDT) is applied to identify the aerodynamic damping of GWT. Good agreement in wind-induced response is found between the two techniques when same damping ratio is used to calculate the wind induced response in the HFBB approach. Generally, the aerodynamic damping of GWT is positive at large scope of wind speed. The results show that the aerodynamic damping increase with the increase of the wind speed and a maximum aerodynamic damping of 1.74% is found when the wind speed at the gradient wind height is 45.4m/s. Then the aerodynamic damping decrease rapidly near the critical wind speed, and finally a minimum aerodynamic damping of–0.06% is found at wind speed of 51m/s.
In part 2, a tuned mass damper (TMD) is applied to reduce the wind-induced vibration of GWT. Wind tunnel experiments are performed to verify the effectiveness of TMD on reducing the wind-induced vibration on super tall building model. The effects of the introduction of a TMD on the vibration of the building model of GWT are analyzed and discussed.
Finally, some conclusions are summarized as the reference for the wind-resistant design of GWT.
引文
[1]全涌,顾明.超高层建筑横风向气动力谱.同济大学学报,2002,30(5):627-632.
[2]全涌,顾明,黄鹏.超高层建筑通用气动弹性模型设计.同济大学学报,2001,29(1):122-126.
[3]全涌,顾明.方形断面高层建筑的气动阻尼研究.工程力学,2004,21(1):26-30.
[4]全涌.超高层建筑横风向风荷载及响应研究.同济大学博士论文,2002.03.01.
[5]顾明,周印,张丰等.用高频动态天平方法研究金茂大厦的动力风荷载和风振响应.建筑结构学报,2000,21(4):55-60.
[6]黄翔,顾明.大跨度结构气弹模型风振响应的阻尼修正系数.同济大学学报, 2004,32(11):1433-1436.
[7]黄鹏,顾明.高层建筑横风向动力干扰效应的试验研究.工程力学,2003,20(5):53-58.
[8]黄鹏,顾明.高层建筑干扰气动阻尼的试验研究.同济大学学报,2003,31(6):652-656.
[9]邹良浩,梁枢果,顾明.高层建筑气动阻尼评估的随机减量技术.华中科技大学学报,2003,20(1):30-33.
[10]楼文娟,孙炳楠.风与结构的耦合作用及风振响应分析.工程力学,2000,17(5):16-22.
[11].黄本才编著.结构抗风分析原理及应用.上海:同济大学出版社,2001.
[12]倪振华编著.振动力学.西安:西安交通大学出版社,1989.
[13]赵林,葛耀君,曹丰产.双曲薄壳冷却塔气弹模型等效梁格设计方法.振动工程学报,Vol.21 No.1,2008.
[14]宋志刚,金伟良.多随机参数下高层建筑风振响应分布特征估计.浙江大学学报(工学版),2004,38(10):1308-1313.
[15]梁枢果,夏法宝,邹良浩等.矩形高层建筑横风向风振响应简化计算.建筑结构学报,2004,25(5):48-54.
[16]王国砚.基于高精度数值积分的结构顺风向风振计算.力学季刊,2006,27(1):162-167.
[17]黄中伟,杨小玲,遇平静.复杂阻尼作用下结构风振的相似性分析.深圳大学学报(理工版),2003,20(4).
[18]瞿伟廉主编.高层建筑和高耸结构的风振控制设计.武汉:武汉测绘科技大学出版社,1991.
[19]欧进萍,张微敬.高层建筑结构的风振阻尼控制分析与设计方法.建筑结构学报,2003,24(6):32-37.
[20]周锡元,阎维明,杨润林.建筑结构的隔震、减振和振动控制.建筑结构学报,2002,23(2):1-12.
[21]黄斌,刘文军.高柔结构的驰振响应分析.特种结构,2004,21(3):63-66.
[22]杨志勇等.影响结构阻尼的部分因素分析.工程力学(增刊),2001,834-837.
[23]何益斌,樊海涛等.建筑结构非线性阻尼及其振动反应研究.湖南大学学报,2006,33(5):41-47.
[24]建筑结构荷载规范.北京:中国建筑工业出版社,2002.
[25]侯爱波,葛楠,周锡元.高层建筑顺风向风振动力反应时程分析.郑州大学学报(工学版),2006,27(2):14-17.
[26]井秦阳,李宏男,王立长等.大连国贸大厦高层水箱风振控制研究及应用.地震工程与工程振动,2006,26(2):111-118.
[27]李祚华,滕军,容柏生等.高层结构屋顶构架风振控制设计与研究.西安建筑科技大学学报(自然科学版),2006,38(4):504-508.
[28]王钦华,王汝恒,贾杉.高层建筑荷载风振系数的风洞试验研究.四川建筑,2005,25(3).
[29]张兆顺,崔桂香,许春晓.湍流理论与模拟.北京:清华大学出版社,2005.
[30]石碧青,谢壮宁,倪振华.用高频底座力天平研究广州西塔的风效应.土木工程学报,2008,41(2):42-48.
[31]谢壮宁,方小丹,倪振华.用多点同步压力扫描方法研究广州西塔的风效应.已投建筑结构学报.
[32]李惠彬编著.大型工程结构模态参数识别技术.北京:北京理工大学出版社,2007.7.
[33] AIJ 1996. AIJ Recommendations for Loads on Buildings.
[34] XinzhongCheng and Ahsan Kareem(2001).Equivalent Static Wind Loads For Buffeting Response Of Bridges.Struct.Engrg,Vol.127,No.12.
[35] Kareem A. Acrosswind response of buildings. J Structural Division,ASCE,108(4):869-887.
[36] M.Kasperski. Extreme wind load distributions for linear and nonlinear design. Eng.Stuct.1992,14(1).
[37] Katagiri J,Marukawa et. Effects of structural damping and eccentricity on wind response of high-rise buildings. Journal of wind engineering and industrial aerodynamics, 74-76(1998):731-740.
[38] Marukawa.H and others. Experimental evaluation of aerodynamic damping of tall buildings. Journal of Wind Engineering and Industrial Aerodynamics,1996,59:177-190.
[39] Watanabe.Y,Isyumov.N.and Davenport,A.G. Empirical aerodynamic damping function for tall buildings. Journal of Wind Engineering and Industrial Aerodynamics,1997,72:313-321.
[40] Q.S.Li,J.R.Wu. Time-frequency analysis of typhoon effects on a 79-storey tall building. Journal of wind engineering and industrial aerodynamics, 95(2007):1648-1666.
[41] Carlo Paulotto,Marcello Ciampoli,Giuliano Augusti.Wind tunnel evaluation of mean wind pressure on a frame-type signboard. Journal of wind engineering and industrial aerodynamics, 94(2006):397-413.
[42]石碧青,洪海波,谢壮宁,倪振华.大气边界层风洞流场特性的模拟.空气动力学学报,2007, 25(3):376-380.
[43] GU Ming,ZHOU Yin,ZHANG Feng,et al. Dynamic responses and equivalent wind loads of the Jin Mao Building in Shanghai. Larsen A,Larose GL,Livesey F M.Wing Engineering into 21th Century. Copenhagen: A A Balkema,1999.
[44]林颖儒,徐晓明,黄本才,王国砚.上海虹口足球场大悬挑钢屋盖结构自振特性和风振动力响应分析.空间结构,2001,7(3):12-17.
[2]全涌,顾明,黄鹏.超高层建筑通用气动弹性模型设计.同济大学学报,2001,29(1):122-126.
[3]全涌,顾明.方形断面高层建筑的气动阻尼研究.工程力学,2004,21(1):26-30.
[4]全涌.超高层建筑横风向风荷载及响应研究.同济大学博士论文,2002.03.01.
[5]顾明,周印,张丰等.用高频动态天平方法研究金茂大厦的动力风荷载和风振响应.建筑结构学报,2000,21(4):55-60.
[6]黄翔,顾明.大跨度结构气弹模型风振响应的阻尼修正系数.同济大学学报, 2004,32(11):1433-1436.
[7]黄鹏,顾明.高层建筑横风向动力干扰效应的试验研究.工程力学,2003,20(5):53-58.
[8]黄鹏,顾明.高层建筑干扰气动阻尼的试验研究.同济大学学报,2003,31(6):652-656.
[9]邹良浩,梁枢果,顾明.高层建筑气动阻尼评估的随机减量技术.华中科技大学学报,2003,20(1):30-33.
[10]楼文娟,孙炳楠.风与结构的耦合作用及风振响应分析.工程力学,2000,17(5):16-22.
[11].黄本才编著.结构抗风分析原理及应用.上海:同济大学出版社,2001.
[12]倪振华编著.振动力学.西安:西安交通大学出版社,1989.
[13]赵林,葛耀君,曹丰产.双曲薄壳冷却塔气弹模型等效梁格设计方法.振动工程学报,Vol.21 No.1,2008.
[14]宋志刚,金伟良.多随机参数下高层建筑风振响应分布特征估计.浙江大学学报(工学版),2004,38(10):1308-1313.
[15]梁枢果,夏法宝,邹良浩等.矩形高层建筑横风向风振响应简化计算.建筑结构学报,2004,25(5):48-54.
[16]王国砚.基于高精度数值积分的结构顺风向风振计算.力学季刊,2006,27(1):162-167.
[17]黄中伟,杨小玲,遇平静.复杂阻尼作用下结构风振的相似性分析.深圳大学学报(理工版),2003,20(4).
[18]瞿伟廉主编.高层建筑和高耸结构的风振控制设计.武汉:武汉测绘科技大学出版社,1991.
[19]欧进萍,张微敬.高层建筑结构的风振阻尼控制分析与设计方法.建筑结构学报,2003,24(6):32-37.
[20]周锡元,阎维明,杨润林.建筑结构的隔震、减振和振动控制.建筑结构学报,2002,23(2):1-12.
[21]黄斌,刘文军.高柔结构的驰振响应分析.特种结构,2004,21(3):63-66.
[22]杨志勇等.影响结构阻尼的部分因素分析.工程力学(增刊),2001,834-837.
[23]何益斌,樊海涛等.建筑结构非线性阻尼及其振动反应研究.湖南大学学报,2006,33(5):41-47.
[24]建筑结构荷载规范.北京:中国建筑工业出版社,2002.
[25]侯爱波,葛楠,周锡元.高层建筑顺风向风振动力反应时程分析.郑州大学学报(工学版),2006,27(2):14-17.
[26]井秦阳,李宏男,王立长等.大连国贸大厦高层水箱风振控制研究及应用.地震工程与工程振动,2006,26(2):111-118.
[27]李祚华,滕军,容柏生等.高层结构屋顶构架风振控制设计与研究.西安建筑科技大学学报(自然科学版),2006,38(4):504-508.
[28]王钦华,王汝恒,贾杉.高层建筑荷载风振系数的风洞试验研究.四川建筑,2005,25(3).
[29]张兆顺,崔桂香,许春晓.湍流理论与模拟.北京:清华大学出版社,2005.
[30]石碧青,谢壮宁,倪振华.用高频底座力天平研究广州西塔的风效应.土木工程学报,2008,41(2):42-48.
[31]谢壮宁,方小丹,倪振华.用多点同步压力扫描方法研究广州西塔的风效应.已投建筑结构学报.
[32]李惠彬编著.大型工程结构模态参数识别技术.北京:北京理工大学出版社,2007.7.
[33] AIJ 1996. AIJ Recommendations for Loads on Buildings.
[34] XinzhongCheng and Ahsan Kareem(2001).Equivalent Static Wind Loads For Buffeting Response Of Bridges.Struct.Engrg,Vol.127,No.12.
[35] Kareem A. Acrosswind response of buildings. J Structural Division,ASCE,108(4):869-887.
[36] M.Kasperski. Extreme wind load distributions for linear and nonlinear design. Eng.Stuct.1992,14(1).
[37] Katagiri J,Marukawa et. Effects of structural damping and eccentricity on wind response of high-rise buildings. Journal of wind engineering and industrial aerodynamics, 74-76(1998):731-740.
[38] Marukawa.H and others. Experimental evaluation of aerodynamic damping of tall buildings. Journal of Wind Engineering and Industrial Aerodynamics,1996,59:177-190.
[39] Watanabe.Y,Isyumov.N.and Davenport,A.G. Empirical aerodynamic damping function for tall buildings. Journal of Wind Engineering and Industrial Aerodynamics,1997,72:313-321.
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