沿海地区高层建筑抗风现场实测研究

发布时间：2018-01-22 06:42

本文关键词： 高层建筑现场实测风特性风压风洞试验风致响应玻璃幕墙　出处：《湖南大学》2015年博士论文　论文类型：学位论文

【摘要】：由于轻质高强材料的应用使得现代高层建筑呈现出高柔和低阻尼特性,高层建筑在强风中的振动有可能引起结构的塑性变形,尤其是围护结构的破坏时有发生,强风引起的风荷载往往是此类建筑结构设计的主要控制荷载。我国每年都有台风在东南沿海地区登陆,造成大量的房屋损坏和其他结构物的破坏,也威胁着沿海地区高层建筑的安全性及其居住者的舒适性。因此,有必要对沿海地区高层建筑在台风作用下的风效应进行系统的研究。现场实测是结构抗风研究的主要方法之一。本文基于厦门沿海的三栋高层建筑A、B和C建立了抗风现场实测的基地,并对高层建筑在台风作用下的风效应开展长期、系统的的抗风现场实测研究。现场实测的内容包括建筑顶部的风场实测、建筑表面的风压实测、不同楼层的加速度响应实测,以及对玻璃幕墙的中空玻璃的风致应力测量。经过几年的台风监测获得了大量的实测资料,并形成了一套较为完善的抗风现场实测研究方法。基于五次台风风场的实测数据,分析了高层建筑顶部的风特性,包括平均风速风向、湍流度、阵风因子、湍流积分尺度和脉动风速谱等。其中,在台风“天兔”中对三栋建筑顶部的风场进行了同步实测,并具体的对比研究了三栋建筑顶部风特性和风速相关性。台风实测得到的风速时程往往具有非平稳性。本文改进了基于非平稳风模型的风特性方法中对时变平均风速的提取方法,对实测风场数据采用非平稳风模型分析了其风特性,其结果表明非平稳风模型对实测风速的湍流度的估计更加合理。基于在建筑C的第33层和第17层的多点风压实测数据,分析了各测点的风压系数、脉动风压的概率分布特性、峰值因子、以及脉动风压的功率谱和相关性。研究表明:当选取样本的来流风向比较平稳时,各10min子样本风压系数间的差异很小,测点所处的位置及脉动风压的概率分布特性对风压系数的影响较大;在保证率相同的情况下,实测风压的峰值因子大于基于高斯分布假设的峰值因子;迎风面测点脉动风压的气动导纳函数与Kawai提出的指数函数曲线的衰减规律相吻合,迎风面测点的相关系数大于背风面,其频率平均的相干函数值与测点间距离的关系可以由一组的指数函数来模拟。通过对建筑C在A类和B类风场条件下的风洞试验研究,对建筑表面的风压分布特性进行了分析,给出了两类地貌条件下得到的建筑各面的体型系数。通过对比风洞试验与实测风压的结果,发现两者所获得的平均风压系数结果基本一致,但现场实测中部分测点的脉动性很强,可能产生较大的峰值风压系数。基于台风作用下在建筑C的6个楼层的风致加速度响应的现场实测,获得了该结构的前6阶自振频率和结构在两个方向上的前两阶平动振型,并分析了加速度响应的均方根与平均风速的关系。本文建立了合理的三维有限元模型,其模态分析的结果与实测结果很接近。将模拟得到的A类地貌下的二维风场作为结构的顺风向脉动风荷载激励施加到有限元模型上,通过时程分析的方法得到了结构的顺风向风致响应,其结果与规范方法的计算结果比较吻合,与实测的加速度响应的结果也很接近。中空玻璃幕墙是高层建筑中较常采用的外围护结构,中空玻璃在风荷载作用下主要发生弯曲变形。本文首先利用幕墙抗风压检测设备对中空玻璃幕墙试件进行了风压加载试验,然后测量了在台风作用下建筑C幕墙中空玻璃的风致应力,重点分析了中空玻璃在风压作作用下的风致应力。结合中空玻璃单元的构造和承载特点,通过理论分析提出了中空玻璃单元受弯承载性能分析的简化方法和有限元分析方法。
[Abstract]:Due to the application of lightweight materials because of the modern high-rise building exhibits high soft and low damping, vibration of high-rise buildings in strong winds are likely to cause plastic deformation of the structure, especially the structure of the damage occurred, the wind load caused by strong winds is usually the main control load design of these structures. There is a typhoon landing in the southeast coastal area of our country every year, causing a lot of damage to housing and other damage to structure, high-rise buildings also threaten the safety of coastal area and the comfort of the occupants. Therefore, it is necessary to carry out systematic research on wind effects on tall buildings in coastal areas under typhoon is one of the main field. Study on method of structures. In this paper, the coast of Xiamen in three high-rise buildings based on A, B and C established a wind field test base, and the high-rise building under typhoon wind The effect of long-term, the wind field measurement system research. The measured wind field measurement includes the pressure building on top of a building, the surface of the measured responses of different floors and wind-induced acceleration, hollow glass of the glass curtain wall stress measurement. After several years of typhoon monitoring and obtained a large amount of measured data, and formed a set of more perfect wind field measurement method. The measured data of five typhoon wind field based on the analysis of the characteristics of the wind at the top of the high-rise buildings, including the average wind speed and direction, turbulence intensity, gust factor, turbulence integral scale and wind spectrum. Among them, the typhoon Usagi in wind field the top three buildings were synchronously measured, and the comparative study of the three buildings at the top of the wind characteristics and wind velocity correlation. Typhoon measured time history is non-stationary. This change The extraction method of time synchronization method of non-stationary wind characteristics of mean wind speed wind model based on the measured wind data using non-stationary wind model analysis of the wind characteristics, the results show that the estimation of non stationary wind turbulence model of measured wind speed is more reasonable. Multi point pressure measurement data in building C the thirty-third layer and seventeenth layer based on the analysis of the wind pressure coefficient of each point, the probability distribution characteristics of fluctuating wind pressure, peak factor, and the fluctuating wind pressure power spectrum and the correlation. The results show that: when the sample of the flow direction is relatively stable, the difference between the 10min sub sample pressure coefficient is very small, the influence of probability the location and distribution characteristics of fluctuating wind pressure measuring points located on the wind pressure coefficient is relatively large; in the guarantee rate under the same condition, the peak peak factor is greater than the pressure factor based on the Gauss distribution; windward point fluctuation The attenuation law of wind aerodynamic admittance function and exponential function curve proposed by Kawai coincide, windward correlation coefficient is larger than the leeward side, the coherence function relationship with distance measuring points by a set of exponential function to simulate the average frequency. Through the construction of C in a class and B class wind under the conditions of wind tunnel test, wind pressure distribution on the surface of the architecture is analyzed, two kinds of landform conditions were given the building shape coefficient. Through the comparison with the measured wind pressure wind tunnel test results, the results found that the average wind pressure coefficient are obtained basically the same, but in the field of measuring pulse the point is very strong, may produce a larger peak wind pressure coefficient. Field test of wind-induced acceleration under typhoon C in building 6 floors based on response, obtained the structure of the first 6 natural frequencies. The direction of the two of the first two order translation mode, and analyzes the relationship between the RMS acceleration response and average wind speed. In this paper, a 3-D finite element model was established, the modal analysis results and the test results are very close. The simulation results of a two-dimensional terrain wind field structure as the wind the fluctuating wind load excitation applied to the finite element model, through the method of time history analysis by wind structure wind induced responses, the results of calculation results agree well with the standard method, the response and the measured acceleration results is very close. Hollow glass curtain wall retaining structure is often used in high-rise building. Hollow glass under wind load mainly bending deformation. This paper uses wall anti wind pressure testing equipment for hollow glass curtain wall specimens of wind loading test, and then measured in typhoon Building C hollow glass curtain wall of wind stress, focus on the analysis of the hollow glass in the wind as the wind stress. And combined with the characteristics of bearing structure of hollow glass unit, is presented through theoretical analysis. The simplified method and the finite element analysis of flexural bearing performance of insulating glass unit.

【学位授予单位】：湖南大学
【学位级别】：博士
【学位授予年份】：2015
【分类号】：TU973.213

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