【作者】 郑斌；

【导师】 肖仪清；

【作者基本信息】 哈尔滨工业大学 ， 结构工程， 2014， 硕士

【摘要】 我国东南沿海常年受到台风侵袭，台风的强致灾性给该地区造成巨大经济财产损失的同时也对建筑结构的抗风安全性提出了更高要求。阵风因子表征了自然风的脉动强弱，是建筑结构抗风设计的重要参量。本文基于台风场实测资料对阵风因子的取值及其影响因素展开了系统研究，主要内容可概括为以下三个方面：搭建了一套可移动式台风近地层风场特性实测网络。该网络由8个2.5米高的近地测风塔构成，具有安置灵活、使用高效的特点，可实现台风近地层风场的空间多点同步观测。利用该实测网络开展了一次近地常态风观测实验，对实测资料进行了风场特征分析，主要包括湍流积分尺度、脉动风速谱、相关系数、相干函数等。从脉动风的空间相关性出发，提出了一种考虑平均风速和结构尺寸效应的阵风因子确定方法。首先基于滑动平均滤波与气动导纳等效原则建立了阵风时距的合理确定方法，并通过对比分析5种常用的气动导纳函数，获得了等效阵风时距计算公式。然后针对实测脉动风较强的非高斯特征，推导了非高斯过程（包含硬化高斯过程和软化高斯过程）的阵风因子理论模型，并利用实测数据对该模型准确性进行了检验。最后将上述阵风因子理论模型用于实测阵风因子修正，利用2006-2008年间影响我国的三次台风过程实测资料，给出了A、B两类场地经修正后的阵风因子曲线，从而建立了合理确定阵风因子的完整流程。为探究实测台风场中部分较大阵风因子值的合理性及其形成机理，从375个台风场实测样本中选取了8个阵风因子值异常偏大的非常态样本以及1个极端异常样本进行了系统研究。首先针对样本所处台风风场位置、样本的非高斯特性和非平稳特性等表观因素进行了初步分析；然后借助小波变换的多尺度分析方法着重研究了湍流间歇性的影响，比较了相干结构提取前后样本各尺度间歇性、能量分布、非平稳性、非高斯性以及实测阵风因子值的变化情况，最终分析认为非高斯与非平稳性是引起非常态阵风因子的直接原因，而多尺度相干结构造成的湍流间歇性为其本质根源。更多还原

【Abstract】 Typhoon strikes southeast China and causes great damages every year,asking for a higher requirement on safety of wind resistenec design. Gust factor,which is a key parameter to measure the strength of turbulence, plays animportant role in wind resistence design. This dissertation will focus on thedetermination of gust factor and its corresponding influence factors based onfield measured data in typhoon field; mainly includes the following three parts.A movable observing network for near surface typhoon field is established.This network is made up by8observing towers and has the merit of flexible andefficient. With the help of it, a simultaneous multi-point observation of typhooncould be done. Field measurement of natural wind was carried out and the windproperties like turbulence integral scale, wind spectrum, correlation coefficientand coherence function were analysised with the obtained dataA method to determine gust factor considering mean wind speed andstructure dimension effect is put forward. First the determination principle ofgust duration is achieved through the equivalence between running average filterand aerodynamic admittance (AA). Five common AAs are investigated and acomprehensive formula is got. Then, a theoretical formula of gust factor fornon-Gaussian process(harden and soften) is deduced to consider thenon-Gaussian property of natural wind, and the validity of the formula is checked.At last, data from three typhoons during2006-2008are used and the theoreticalformula revised gust factor curve for terrain A and B are presented at the end.Thus, a reasonable determination approach for gust factor has been set up.To explore the rationality and forming mechanism of some large gust factorin typhoon field,8anomalous gust factor samples and an added extreme one areselected from375field measured samples in typhoon. At first, influence factorslike positions in typhoon field, non-Gaussian and non-stationary property areinvestigated. Then a detailed research on coherent structure is carried out withwavelet transform. The changes of multi scale energy distribution, non-Gaussian,non-stationary property and gust factor values before and after the extraction ofcoherent structure are compared, showing that, turbulence intermittency causedby multi-scale coherent structure, is the root of anomalous gust factor, whilenon-Gaussian and non-stationary property of the time series are the direct causes.更多还原