对中、美、日现行荷载规范的城市地貌风特性开展了对比研究。分析了平均时距、地面粗糙度系数、梯度风高度的取值原则,研究了3种规范给定的湍流强度、湍流积分尺度及脉动风速谱经验公式的差异。基于实测结果评估了风特性关键参数的准确性。结果表明,3种规范规定的地面粗糙度系数及梯度风高度均小于实测结果,美国规范预估的湍流强度与实测值最为接近,日本规范的湍流积分尺度及脉动风速谱经验模型与实测结果符合较好,研究结果将为城市地区建筑结构的抗风设计提供技术参考。
A comprehensive comparison study of wind characteristics over urban area was conducted utilizing three major international codes: GBS0009--2012(China), ASCE-2010 (USA), AIJ-RLB-2004 (Japan). The calculation principles of some selected parameters such as averaging time, ground roughness exponent and gradient height were reviewed in detail. The turbulence parameters including turbulence intensity, turbulence integral length scale and power spectral densities recommended in three codes were presented and discussed. A comparison between the parameters of wind characteristics determined based on the measured wind data and those estimated by GB50009--2012, ASCE 2010, AIJ-RLB- 2004 was carried out. The results reveal that the ground roughness exponent and gradient height predicted by three building codes are smaller than those obtained by the field measurements. The longitudinal turbulence intensity values determined by ASCE- 2010 are in closer agreement with the measured ones. The turbulence integral length scale and power spectral densities recommended by AIJ-RLB--2004 basically agree with the measured results. The objective of this study aimed to provide useful information on boundary layer wind characteristics for the wind resistant design of structures in urban areas.