新旧荷载规范中高耸结构的等效静力风荷载比较

Comparison of equivalent static wind loads of high-rise structures between the new and old load codes

利用随机振动理论建立结构风振系数、等效静力风荷载的理论公式。定义新旧规范的风振系数之比、等效静力风荷载之比2个参数,通过理论分析得到它们的上限值和下限值,从而确定新规范的风振系数、等效静力风荷载相较旧规范的变化范围。因为新规范大幅度提高了10 m高处的紊流度,高耸结构新规范的风振系数要大于旧规范,在某些情况下会达到旧规范的1.40~1.59倍。4种地貌下,新、旧规范的等效静力风荷载之比的下限值分别为0.93、0.97、0.88、0.83,上限值分别为1.44、1.36、1.38、1.32。对高、柔的高耸结构,其等效静力风荷载最大会达到旧规范的1.32~1.44倍。

Theoretical formulas of wind-induced vibration coefficients(WVC)and static equivalent wind load(SEWL)of high-rise structures are established using random vibration theory.The ratio of the WVC,λβ,and the ratio of the SEWL,λF,of the new and old codes in China are defined,and their upper and lower limits are obtained using theoretical analysis.The variation ranges of the wind vibration coefficient and equivalent static wind load of the new code compared with the old code are determined.Because the turbulence intensity at 10 m height is greatly improved in the new code,the WVC of the new code is larger than that of the old code,and in some cases,it is 1.40-1.59 times of the old one.For 4 landforms,the lower limits of the ratioλF are 0.93,0.97,0.88,0.83,respectively;and the upper limits are 1.44,1.36,1.38,1.32,respectively.For tall and soft highrise structures,the SEWL of the new code reaches 1.32-1.44 times of the old one.