圆截面高柔结构横风向风荷载规范对比分析

Comparative Analysis of Cross-wind Load Code for Circular High Structures

为了研究国内外圆截面高柔结构横风向荷载规范的差异和适用性,选取8座有实测位移数据的钢烟囱和钢混烟囱为算例,分别采用中国、欧洲(方法Ⅰ、Ⅱ)、日本、加拿大和美国荷载规范计算了烟囱位移,将规范所计算的位移结果与实测位移进行对比分析。结果表明,对于钢烟囱,中、日规范的位移计算值约为实测值的30%,加、欧Ⅰ规范的计算值约为实测值的70%;对于钢混烟囱,中国规范计算值小于实测值,其他各规范计算值均远大于实测值。整体来说,国内外圆截面高柔结构风荷载规范所计算的横风向位移结果与实测值差异显著,尤其对轻质、小阻尼钢烟囱的风荷载计算结果都偏于危险,不同规范的适用性仍存在问题,在进行圆截面高柔结构抗风设计时应慎重选择荷载规范。

In order to study the difference and applicability of cross-wind load for high-flexible structures with circular cross-section in different codes,8 chimneys with full-scale measured displacement are selected.The codes of China,Europe(code Ⅰ and Ⅱ),Japan,Canada and the United States are used to calculate the displacement of the full-scale chimneys,and the measured displacement is compared with the calculated value of the code.The results show that the estimated displacement of Chinese and Japanese code is about 30% of the measured value for steel chimneys,and the American,Canadian and European(code Ⅰ) code is about 70% of the measured value.For reinforced concrete chimneys,the calculated value of Chinese code is less than the measured value,and the calculated value of other specifications is much larger than the measured value.Overall,the wind load of high-flexible structures with circular section in different codes can not calculate the actual displacement well,in particular,the wind load estimation of light and small damping steel chimneys towards danger,and there are still some problems in the applicability of each code.The load code should be carefully chosen in the wind-resistant design stage for high flexible structures with circular section.