单筒砼烟囱中美标风荷载计算对比浅析

本文以某石化单筒式钢筋混凝土烟囱为例,从基本风速、顺风向风荷载、横风向共振、环向风弯矩入手,对比分析了单筒钢筋混凝土烟囱中美标风荷载计算的差异。分析得出:1)美标基本风速约为中规的1.423倍;2)顺风向风荷载计算差异较大,美标顺风向风荷载截面弯矩是中规的1.6~1.9倍;3)二者均为第一振型不考虑横风向风荷载,第二振型横风向风荷载美标约为中规的4.5倍;烟囱1/3高度以下横风向与顺风向风荷载组合弯矩中规是美标的1.2到1.6倍,随着高度上升,美标与中规截面弯矩比大幅度增大,顶部约3.5倍;4)美标环向风弯矩是中规的1.8~2.7倍。

Comparison of wind load calculation differences between Chinese and American codes for single tube concrete chimney

In this paper,taking a petrochemical single tube reinforced concrete chimney as an example,starting from the basic wind speed,along wind load,cross wind resonance and circumferential wind bending moment,the differences of wind load calculation between Chinese and American codes for single tube reinforced concrete chimney are compared and analyzed.The results show that:1)The basic wind speed of American standard is about 1.423 times of that of China standard.2)The calculation of the along-wind load is quite different,and the along-wind load section bending moment of American is 1.6~1.9 times of that of Chinese.3)The first mode does not consider the across wind load for both,and the across-wind load of the second mode in American is 4.5 times of that of Chinese.For across-wind and along-wind load combination bending moment,the Chinese is is 1.2 to 1.6 times of American standard below 1/3 height of chimney,however,with the increase of height,the section bending moment ratio of American and Chinese increases greatly,about 3.5 times at the top;4)The circumferential wind bending moment of American is 1.8~2.7 times of that of Chinese.