高层建筑顺风向响应规范计算及试验研究

RESEARCH ON ALONG-WIND RESPONSE FOR HIGH-RISE BUILDINGS BETWEEN DIFFERENT CODES BASED ON WIND TUNNEL TEST

作为对高层建筑起控制作用的风致振动,顺风向响应在抗风设计中尤为重要。多国风荷载规范均给出了典型的矩形断面形式的高层建筑顺风向响应计算方法,但不同的计算方法导致结果存在偏差。以某矩形高层建筑为例,基于风洞试验比较研究中国、美国及加拿大规范计算方法。研究表明:因平均风速定义的差异,中国风振系数取值要高于美国的阵风影响系数;相比频域法的计算结果,中国规范中采用的惯性风荷载法计算结果偏大;在相同风荷载作用下,中国和加拿大规范方法得到的顺风向最大位移响应值偏大,结构设计偏于保守。美国规范的计算结果相对偏小,相对偏于不安全;相比于加拿大阵风荷载因子法,中国惯性风荷载法风致响应偏小。

As a control factor of wind-induced vibration for high-rise building structures, the along-wind response is especially important in structural wind-resistant design. The calculation method with a typical rectangular section is clearly given in the multinational wind load codes and design guides. However, due to the diversities of different methods, calculation results present certain differences. The paper presented a detailed comparison among three national codes (China, America, Canada) of along-wind displacement response calculation for rectangular high-rise buildings. The comparison was presented between wind tunnel tests and numerical calculation on a certain high-rise building. The study found that due to the difference in the definition of mean wind speed, the wind-induced vibration coefficient defined in Chinese code was higher than the gust effect factor defined in American code. Comparing with the results of the displacement response by frequency domain method often used in engineering, the results calculated by the inertial wind load method adopted in the Chinese load code was larger. Under the same wind load, the maximum along-wind response values calculated through the load code of China and Canada were larger, the structural design was conservative, and the results calculated through the United States Code were relatively small, that was, the design was insecure relatively. Compared to the gust load factor method of Canada, the wind- induced response obtained by the inertial wind load method of China was relatively small.