基于风洞试验的海峡两岸高层建筑顺风向风荷载安全性评估

Safety Evaluation of Along-Wind Loads on High-Rise Buildings Between Chinese Taiwan and Chinese Mainland Based on Wind Tunnel Test

摘要:

为明确海峡两岸高层建筑顺风向风荷载的合理取值，对两岸标准中的风荷载分布和基底响应进行了对比分析，并采用刚体模型测压风洞试验对顺风向风荷载取值的安全性进行了评估。研究表明：随着结构高宽比的增大和地面粗糙度的减小，两岸规范给出的结构顺风向风荷载均逐渐增大，且台湾规范计算值的增速要快于大陆规范；高宽比越大、地面粗糙度越小，台湾规范给出的风荷载计算值相对越大；随着结构高宽比的增大，台湾规范的阵风反应因子逐渐增大，而大陆规范的等效风振系数基本不变，结构动力放大系数取值方法不同是造成两岸标准中高层建筑顺风向风荷载区别的主要原因；对于台湾规范A、B、C类风场，风洞试验获得的顺风向风荷载分布形状与台湾规范大致相同，而与大陆规范存在较大区别；以风洞试验获得结构顺风向基底响应极值为检验标准，台湾规范值相对误差的离散程度明显大于大陆规范，当结构高宽比越小时，大陆规范的计算结果相对更安全，当结构高宽比较大时，台湾规范的计算结果相对更安全。

Abstract:

To clarify the reasonable values of along-wind loads on high-rise buildings between Chinese Taiwan and Chinese mainland， a comparative analysis was conducted based on wind load distribution and base response calculated according to the standards of both sides. Additionally， a rigid model pressure measurement wind tunnel test was performed to evaluate the safety of the along-wind load values. The results show that as the height-to-width ratio of the structure and ground roughness decreases， the calculated along-wind loads in both standards gradually increase. However， the increase in the standard of Chinese Taiwan is pronounced than that in the standard of Chinese mainland. Specifically，as the height-to-width ratio increases and ground roughness decreases， the calculated wind loads in the standard of Chinese Taiwan are relatively high. Furthermore， as the height-to-width ratio increases， the gust response factor in the standard of Chinese Taiwan gradually increases， while the equivalent wind vibration coefficient in the standard of Chinese mainland remains essentially unchanged. The primary source of the in along-wind loads between the two standards is the variation in methods for determining the structural dynamic amplification factor. For wind fields under the terrain category A， B and C， of the standard of Chinese Taiwan， wind tunnel test reveals that the shape of the along-wind load distribution aligns closely with the standard of Chinese Taiwan but differs significantly from the standard of Chinese mainland.When the extreme along-wind base response derived from the wind tunnel test is used as a benchmark， the relative error dispersion of values in the standard of Chinese Taiwan is noticeably larger than that in the standard of Chinese Taiwan. The results suggest that when the height-to-width ratio is smaller， the standard of Chinese mainland yields relatively safer results， while the standard of Chinese Taiwan provides safer results when the ratio is larger.