深圳京基100风致响应实测研究

采用自主研发的LAC-I无线加速度传感器,对高度441.8 m的深圳京基100(KK100)的加速度响应进行了为期5年的连续监测。选取了2011年至2015年间的4次主要台风(纳沙、杜苏芮、维森特和天兔)经过时的加速度观测数据以及常态弱风和环境激励下的加速度数据,进行结构动力参数识别以及验证与风洞试验结果的一致性。结果表明:各工况下自振频率的识别结果具有很好的一致性,与其在设计阶段对结构进行有限元分析得到的相应结果约大21%;阻尼比的识别结果表现出一定的离散性,x、y两个方向的阻尼比分别在0.6%~0.9%和0.33%~0.71%之间变化,但阻尼比与振幅并不存在明显的相关性;在风场条件基本一致的情况下,实测结果与风洞试验结果具有良好的一致性;在振幅较大的横风向,实测和风洞试验得到的结构顶部峰值加速度响应相差4.2%,说明了风洞试验的可靠性。同时近5年来的连续观测遇到了与深圳地区10年重现期风压相当的最大风速,测得的瞬时峰值加速度仅为0.123 m/s2,表明该建筑的舒适度能够满足要求。     

Study on full-scale measurements of wind-induced response of the Shenzhen Kingkey 100 Tower

采用自主研发的LAC-I无线加速度传感器，对高度441.8m的深圳京基100 (KK100)的加速度响应进行了为期5年的连续监测。选取了2011年至2015年间的4次主要台风（纳沙、杜苏芮、维森特和天兔）经过时的加速度观测数据以及常态弱风和环境激励下的加速度数据，进行结构动力参数识别以及验证与风洞试验结果的一致性。结果表明：各工况下自振频率的识别结果具有很好的一致性，与其在设计阶段对结构进行有限元分析得到的相应结果约大21%；阻尼比的识别结果表现出一定的离散性，x、y 两个方向的阻尼比分别在0.6%~0.9%和0.33%~0.71%之间变化，但阻尼比与振幅并不存在明显的相关性；在风场条件基本一致的情况下，实测结果与风洞试验结果具有良好的一致性；在振幅较大的横风向，实测和风洞试验得到的结构顶部峰值加速度响应相差4.2%，说明了风洞试验的可靠性。同时近5年来的连续观测遇到了与深圳地区10年重现期风压相当的最大风速，测得的瞬时峰值加速度仅为0.123 m/s²，表明该建筑的舒适度能够满足要求。     

台风激励下海口市某高层建筑模态参数识别

对2014—2017年期间一栋由4根巨柱支撑、高108m的32层塔楼在台风影响下的楼顶风场和动力响应进行同步监测，获得台风“威马逊”、“海鸥”、“彩虹”、“莎莉嘉”和“卡努”影响下该楼顶部的风速、风向和不同楼层沿长、短轴向的加速度响应时程，分析了加速度响应的时域和频域特性，采用ERA-NExT、RDT、有限元法识别了实测高层建筑的模态参数，研究了与加速度幅值相关的模态频率和阻尼比。统计结果表明：强风作用下高层建筑模态频率低于静风状态下的模态频率，当加速度均方根小于10mm/s²时，顺、横风向前三阶模态频率随加速度幅值增大而减小，顺风向前三阶模态阻尼比随加速度幅值增大而增大；当加速度均方根大于10mm/s²时，顺、横风向前三阶模态频率减小速率逐步减小，顺风向前三阶模态阻尼比未出现明显增大。当峰值加速度达到最大时，沿长、短轴向一阶模态阻尼比约为2.0%、1.9%，相比静风状态下前三阶模态频率下降了约11%、12%、10%，并提出了考虑相对加速度幅值(加速度均方根与测点离地高度比值)参数影响的高层建筑基频预测公式，为台风多发区域高层建筑基频的估算提供参考。     

超强台风“山竹”期间珠三角地区超高层建筑的风效应实测研究

对超强台风“山竹”侵袭时珠三角地区数栋超高层建筑的风致响应实测结果进行分析和总结,开展内伶仃岛缩尺模型风洞试验,获取该岛对气象站点风速的影响系数,并依此对观测风速进行订正,结合实测和风洞试验分析和评价深圳湾壹号7号塔楼(T7)的抗风性能。结果表明：不同高度、平立面外形的超高层建筑实测风致最大峰值加速度均超过10 cm/s2,且超高层建筑风振响应和建筑高度不存在相关性;在所有被测的建筑中加速度响应最小的建筑为高度342 m的T7,其最大峰值加速度仅为13.2 cm/s2;参数识别得到T7的模态频率和阻尼比显示均具有明显的时变特征,最大风速时段识别的模态频率整体上较有限元数据模拟结果增大21%,前两阶模态阻尼比分别为2.1%和1.7%;优化的气动外形和合理的朝向是T7抗风性能优良的主要原因,对于一般矩形平面的超高层建筑应避免使其窄边面向所在地的强风主导风向;采用订正后的风速值和参数识别结果对风洞数据进行重分析,结果显示计算值和实测值吻合较好,验证了前期风洞试验的可靠性。     

台风边缘区风场特性及其作用下高耸桅杆结构风效应实测研究

以深圳356 m气象梯度塔记录的风速时程数据为基础，分析了台风“圆规”边缘区风场平均风速、湍流度及风谱特性，并进一步探讨了台风作用下梯度塔的风致响应特征。结果表明：台风边缘区域大风时段风剖面指数均值为0.243,高度40 m以下湍流强度介于GB 50009—2012《建筑结构荷载规范》中C类与D类场地之间，高度320 m处湍流强度则接近C类场地的；von Karman谱与高度320 m处实测风谱吻合较好，但与低空实测谱存在一定差异；台风激励下梯度塔以横风向振动为主，且风振多模态参与特征明显，纤绳振动不可忽略；结构加速度响应幅值对梯度塔的模态频率和阻尼存在一定影响；结构x向和y向前三阶模态频率整体呈现随加速度响应增大而减小的趋势；阻尼比的识别结果较为离散，y向的前三阶和x向的一阶模态阻尼比随结构加速度响应增大而增大，而x向的二阶和三阶模态阻尼比则随响应增大呈减小的趋势。     

Study on full-scale measurements of wind effect on super high-rise buildings in Pearl River Delta region during super Typhoon Mangkhut

对超强台风“山竹”侵袭时珠三角地区数栋超高层建筑的风致响应实测结果进行分析和总结，开展内伶仃岛缩尺模型风洞试验，获取该岛对气象站点风速的影响系数，并依此对观测风速进行订正，结合实测和风洞试验分析和评价深圳湾壹号7号塔楼(T7)的抗风性能。结果表明：不同高度、平立面外形的超高层建筑实测风致最大峰值加速度均超过10 cm/s2，且超高层建筑风振响应和建筑高度不存在相关性；在所有被测的建筑中加速度响应最小的建筑为高度342 m的T7，其最大峰值加速度仅为13.2 cm/s2；参数识别得到T7的模态频率和阻尼比显示均具有明显的时变特征，最大风速时段识别的模态频率整体上较有限元数据模拟结果增大21%，前两阶模态阻尼比分别为2.1%和1.7%；优化的气动外形和合理的朝向是T7抗风性能优良的主要原因，对于一般矩形平面的超高层建筑应避免使其窄边面向所在地的强风主导风向；采用订正后的风速值和参数识别结果对风洞数据进行重分析，结果显示计算值和实测值吻合较好，验证了前期风洞试验的可靠性。     

厦门沿海某超高层建筑结构风致振动动力特性研究

现场实测是获得结构风致振动动力特性参数的一种较为可靠的手段和方法。通过对厦门沿海某超高层建筑在台风登陆时进行现场原型实测,得到了该建筑结构的第10层、18层、23层、28层、33层和36层的加速度响应时程数据和固有频率及振型等结构的动力特性。根据实测加速度数据,利用随机减量法提取结构两方向的前3阶固有频率对应的阻尼比,结果表明：由于实测时台风风速较大,导致结构风致响应较为显著,因此结构两个方向第1阶阻尼比值在7%左右,明显大于另外两阶阻尼比;两方向第1阶阻尼比与加速度呈非线性关系,阻尼比随加速度的增大而增大。采用ANSYS软件建立该超高层建筑的3D有限元分析模型并进行模态分析,提取该模型的前3阶固有频率和振型,与实测结果进行对比分析,结果较为吻合,由此说明所建立的3D有限元分析模型正确可靠。     

拼腔组合结构风机塔筒系统气动响应性能分析

风电资源开发空间的高度及机组容量日益提高,超高塔筒技术得到广泛研究。本文提出一种适用于陆上风电塔筒结构方案的新型拼腔钢-混凝土组合结构风机塔筒,基于风力机系统气动理论,建立了高140m的4.5MW风力机塔筒数值模型,对其在风载下的动力响应进行了数值模拟,并分析了各参数对结构动力特性的影响规律。结果表明:土壤和基础的耦合作用对塔筒系统的频率及模态阻尼比影响较小;风机塔筒的频率、塔顶位移和加速度响应均能满足规范要求;随着风速增大,塔筒顶部位移减小,加速度增大;结构阻尼比对顶部位移的影响较小,而对顶部加速度的影响较明显。研究结果可为塔筒结构风洞试验提供理论依据。     

正六边形超高层建筑横风向气弹效应研究

为研究正六边形超高层建筑横风向风致响应和气动阻尼比,开展了一系列多自由度气弹模型风洞试验。测量模型顶部风致位移和加速度响应,基于随机减量法识别了横风向气动阻尼比。结果表明,在顶角迎风时,正六边形超高层建筑易于出现大幅涡振现象,在立面迎风时没有出现涡振现象。顶角迎风时,横风向气动阻尼比随折算风速增大呈现出“先增大到最大正值、再迅速转为最小负值,再平稳回升到零值附近”完整过程。而立面迎风时,横风向气动阻尼比与折算风速近似呈线性关系。最后,建立横风向气动阻尼比的经验评估公式。相关研究可为正六边形超高层建筑的抗风设计和规范完善提供参考。     

台北101大楼风致响应实测及分析

台北101大楼主塔楼总高508m共101层,在台风"马莎"和"泰利"影响下,对其风致响应实测资料进行统计分析,评估了典型超高层建筑的风致振动特性。结果表明两次测试的结构模态参数基本吻合,有限元分析的自振频率小于实测结果,计算的振型与测试结果符合较好,利用随机减量方法识别的结构阻尼比与振幅之间呈现非线性关系,并不同程度的表现出随振幅增大而增大的特性,实测的结构一阶阻尼比大于同类超高层建筑物的测试结果,两次台风作用下89层、101层的加速度峰值和均方根均小于规范相应限值,满足舒适度的要求。测试结果为超高层建筑设计及相关研究提供有用的资料及依据。     

Field measurements and wind tunnel experimental investigations of wind effects on Guangzhou West Tower

The wind‐induced acceleration responses at the top of the Guangzhou West Tower (GZWT; 432 m) and the wind speed and direction at the top of Guangzhou Tower (532 m), which is located across the GZWT, were measured during the passage of Typhoon Mangkhut. The two buildings are separated by a river. The variation characteristics of the first two natural frequencies and damping ratios of the GZWT under strong vibrations are obtained by using random decrement technique (RDT) and modified Bayesian spectral density approach (MBSDA). Finally, field measurements of the maximum peak accelerations are compared with wind tunnel test results. The damping ratios identified by MBSDA are found to be greater than the results obtained by RDT. The natural frequencies decrease with increasing maximum acceleration of the corresponding acceleration segment. Besides, they decrease firstly and then increase with time elapses, reaching a minimum value at the maximum mean wind speed. The damping ratios are completely discrete, and no obvious linear correlation exists between the damping ratios and maximum acceleration of the corresponding acceleration segment. The peak accelerations at the top of the GZWT obtained from wind tunnel experiment agree well with that of full‐scale measurements.     

Wind effects on Shenzhen Zhuoyue Century Center: Field measurement and wind tunnel test

Field measurements of wind effects on Zhuoyue Century Center were conducted during 4 typhoon events in the recent 5 years, during which the field data such as wind speeds, wind directions, and acceleration responses were simultaneously and continuously measured. On the basis of field measured data, dynamic characteristics of this super‐tall building were determined by recently developed fast Bayesian fast Fourier transform method. Using full‐scale measurement data under 4 typhoons and breezy conditions for modal identification, one could observe a relatively wide scatter in the identified modal damping ratios, and the damping ratios do not appear to have an obvious nonlinear relationship with vibration amplitude. The average damping ratios of the first 2 modes were 0.70% and 0.73%, respectively. Serviceability of the super‐tall building under wind action was analyzed on the basis of the field measured response. Finally, the measured wind‐induced acceleration responses were further compared with those obtained from the wind tunnel test to evaluate the accuracy of the model test results.     

Monitoring of structural modal parameters and dynamic responses of a 600m‐high skyscraper during a typhoon

This paper presents field measurement results of structural dynamic properties and wind‐induced responses of 600m‐high Ping‐An Finance Center in Shenzhen during the passage of Typhoon Haima. The field measurements included wind speed, wind direction, and structural acceleration responses during the typhoon. Analysis of the field measurements is carried out to investigate the wind‐induced structural vibrations and dynamic properties of the skyscraper under typhoon condition. In the analysis, natural frequencies and damping ratios of Ping‐An Finance Center are estimated using Peak‐Picking method, half‐power bandwidth method in frequency domain, and random decrement technique in time domain, respectively. Two band‐pass filtering methods, namely, elliptical filtering method and Kaiser‐window FIR filter, are adopted to deal with the measured acceleration signals. Consequently, the modal parameters identified with the Peak‐Picking, half‐power bandwidth, and random decrement technique methods are presented and discussed in detail. In addition, the probabilistic characteristics of the recorded acceleration responses are analyzed using the generalized extreme value distribution, and then the serviceability of the skyscraper during the typhoon is evaluated.     

Modal identification of Di Wang Building under Typhoon York using the Hilbert–Huang transform method

The Di Wang Building is one of the tallest composite buildings in the world, located in downtown Shenzhen City of China about 2 km from the Hong Kong border. On 16 September 1999, Typhoon York – that is the strongest typhoon since 1983 and the typhoon of longest duration on record – attacked Hong Kong and Shenzhen. The wind and structural monitoring system installed in the Di Wang Building timely recorded wind and structural response data. The newly emerged Hilbert–Huang transform (HHT) method in conjunction with the random decrement technique (RDT) is applied to the measured data in this paper to identify dynamic characteristics of the building. A series of natural frequencies and modal damping ratios of the building under different wind speeds in different directions are identified and compared with those from the fast Fourier transform (FFT)‐based method. The variations of natural frequency, total modal damping ratio and net structural modal damping ratio with wind speed and vibration amplitude are also investigated. The results show that the natural frequencies identified by the HHT method are almost the same as those obtained by the FFT‐based method. The first two modal damping ratios given by the HHT method are, however, lower than those by the FFT‐based method, which may indicate that the FFT‐based method overestimates the modal damping ratios. Both the total and the net structural modal damping ratios increase with increasing wind speed and vibration amplitude but the situation is reversed for the natural frequency. Copyright © 2003 John Wiley & Sons, Ltd.     

Modal parameter identification of Tsing Ma suspension bridge under Typhoon Victor: EMD-HT method

This paper aims to identify the natural frequencies and modal damping ratios of the Tsing Ma suspension bridge during Typhoon Victor using the newly emerged empirical mode decomposition (EMD) method in conjunction with the Hilbert-transform (HT) technique. Stationary tests on the acceleration responses of the bridge recorded at different locations and in different directions during Typhoon Victor are first carried out to classify the recorded response data. Natural frequencies and modal damping ratios identified by the EMD-HT method are then compared with those obtained by the traditional fast Fourier transform (FFT)-based method. The modal parameters identified by the EMD-HT method from the bridge responses recorded at different locations are compared with each other to check their consistency. Furthermore, the variations of natural frequency and total modal damping ratio with vibration amplitude and mean wind speed are examined. The results demonstrated that the EMD-HT method is applicable to modal parameter identification of large civil structures under typhoons. The EMD-HT method and the FFT-based method produced almost the same natural frequencies but the FFT-based method gave higher modal damping ratios than the EMD-HT method in general.     

Long-term monitoring of wind-induced responses of a large-span roof structure

A long-term monitoring of the wind acceleration responses of the World Cup Stadium's roof structure in Jeju-do, Korea was carried out. Modal properties were extracted from collected data using the system identification technique, and variations of modal properties associated with the change in temperature and vibration amplitude (wind speed) were examined. The investigation indicated that up to a 5% increase in the natural frequencies was accompanied by a 27.2 °C rise in temperature. It also indicated approximately 5% decreases in the natural frequencies and increases of more than twice the damping ratios with an increase in five times the vibration amplitude. In addition, the reliability of the natural frequency prediction for this type of structures using the current analytical technique was examined by comparing with measured natural frequencies. In the FE model, nonlinear effects caused by the geometric stiffness and stress stiffening were included. The analytical natural frequencies showed good agreement with the measured values within a difference of 5%. An analytical prediction of wind-induced responses of the structure was made based on the wind tunnel test results, the analytical natural frequencies and mode shapes, including the added mass effect. Predicted wind-induced responses showed reasonable match with the measured accelerations during typhoons and winter storms.