矩形高层建筑非高斯风压时程峰值因子计算方法  

PEAK FACTOR ESTIMATION METHODS OF NON-GAUSSIAN WIND PRESSURES ON A RECTANGULAR HIGH-RISE BUILDING

作　　者：庄翔[1] 董欣[2] 郑毅敏[1,2] 赵昕[1,2] 

机构地区：[1]同济大学土木工程学院建筑工程系,上海200092 [2]同济大学建筑设计研究院(集团)有限公司,上海200092

出　　处：《工程力学》2017年第7期177-185,223,共10页Engineering Mechanics

基　　金：国家自然科学基金青年基金项目(51408353);上海市青年科技启明星计划项目(15QB1404800)

摘　　要：对一矩形高层建筑进行刚性模型风洞测压试验。首先基于风压时程的3阶矩和4阶矩,对不同风向下,矩形高层建筑表面风压脉动的高斯区与非高斯区进行划分。结果表明,迎风面的非高斯区主要位于迎风边缘及角部。在侧风面,长边迎风时,非高斯区主要集中在迎风前缘附近;短边迎风时,非高斯区位于靠近背风边缘的旋涡再附区。其次,基于Hermite级数法和改进Hermite级数法,通过参数分析和脉动风压谱拟合,提出非高斯风压时程的峰值因子简化计算方法——三参数Hermite级数法。最后,分别通过风压时程中的瞬时极值和风压时程的频数分布直方图验证了Hermite级数法、改进Hermite级数法和三参数Hermite级数法的有效性与准确性。结果表明,与风压时程中瞬时极值所对应的峰值因子相比,Hermite级数法的计算结果则偏于保守,三参数Hermite级数法、改进Hermite级数法的计算结果与其偏差率均小于10%。此外,三参数Hermite级数法和改进Hermite级数法所给出的概率密度曲线基本重合,且与实际风压时程频数分布直方图的贴合程度较优,能够较为准确地反映实际风压时程的概率密度分布。A wind tunnel test was conducted on a rectangular high-rise building. Firstly, based on the third-and the fourth-order statistical moments of wind-pressure time-histories, its non-Gaussian regions were identified. The test results show that on the windward face, the non-Gaussian region was near the edge and the corner areas. For the narrower side face, the non-Gaussian region was near the leading edge. However, the non-Gaussian region was discovered close to the trailing edge where the flow reattachment occurred for the wider side face. Then, by parametric analysis and fluctuating wind-pressure spectrum fitting, a simplified method for peak-factor estimation was derived on the basis of the moment-based Hermite method and the Revised Hermite Model, named Three-parameter Hermite Model. Lastly, the accuracy and efficiency of moment-based Hermite method, Revised Hermite Model, and Three-parameter Hermite Model were tested by the instantaneous extreme value and the histogram of wind-pressure histories. The results show that：compared with the peak factors of the instantaneous extreme values, the peak factors calculated by the moment-based Hermite method were overestimated; while the peak factors of Revised Hermite Model and Three-parameter Hermite Model show a smaller error around 10%. The Probability Density Curves （PDCs） of Three-parameter Hermite Model are in a good agreement with the ones of Revised Hermite Model, which show a better fit to the histogram of wind-pressure histories.

关 键 词：高层建筑 风洞试验 非高斯特性 风压脉动 峰值因子 

分 类 号：TU312.1[建筑科学—结构工程]