超高层建筑横风向风致响应的非高斯性及峰值因子研究

Study on the non-Gaussian characteristic and peak factor of across-wind response for super high-rise buildings

基于单自由度气动弹性模型风洞试验,分析了超高层建筑横风向响应的非高斯性。通过归一化概率密度分布图直观地对比了不同风速,不同风场,不同斯科顿数和正下游干扰建筑对超高层建筑横风向加速度响应非高斯性的影响。通过对比多样本峰值因子观测值,对几种峰值因子取值方法的适用性进行了评估。分析了来流风速、风场、斯科顿数和下游建筑对风致响应峰值因子的影响。结果表明:在低湍流度下,来流接近涡激共振风速时,风致响应会出现显著的非高斯性;风场和干扰位置对风致响应非高斯性有着明显的影响;Davenport法在涡激共振风速和部分高折减风速时过分高估了峰值因子实际值,建筑结构荷载规范给定的峰值因子通常低估了峰值因子实际值,子段极值统计法可以较精确地给出峰值因子。

Based on the wind tunnel tests of the single-degree-of-freedom aeroelastic model,the non-Gaussian behavior of across-wind response of a super tall building was analyzed.The effects of different wind speeds,wind fields,Scruton numbers and interference positions on the non-Gaussian features of across-wind acceleration responses of the super high-rise building were studied by the normalized probability density distribution.The applicability of several methods determining peak factor was evaluated by comparing it with the observed value from multi-sample extreme values.The effects of wind speed,wind field,Scruton number and downstream interference building on the peak factor of wind-induced response were investigated.The results indicate that the wind-induced response shows significant non-Gaussian characteristics when the upcoming flow approaches the vortex-induced resonance wind speed in low turbulence wind field;the wind field and interference spacing have notable influences on the non-Gaussian characteristics of the wind-induced responses;the Davenport method overestimates the peak factors in the vortex-induced-resonance region and some high reduced wind speeds;the actual peak factors are usually underestimated by Chinese Load code;the sub-section extreme-value statistical method can estimate the peak factors more accurately.