不同空间相关函数对铁塔风振系数的影响

Influence of Different Spatial Correlation Functions on Wind Vibration Coefficient of Towers

空间相关函数是描述空间两点脉动风荷载在频域上的相关程度,国内外学者基于实测数据给出了几种不同的空间相关函数,我国规范采用了Shiotani相关函数进行风荷载分析计算,由于其未考虑高度的影响,在计算分析高度不是很高的一般输电线路铁塔时有较强的实用性,但是对于大跨越高塔,有低估脉动风振系数的可能性。本文采用不同脉动相关函数对不同高度铁塔进行分析计算,结果表明,随着高度的增加,与考虑高度影响的相关函数相比,Shiotani计算所得风振系数在塔头段偏低3%~11%,全塔加权值偏低3%~5.5%左右,因此在设计大跨越高塔时,建议适当考虑高度对空间相关系数的影响。

The spatial correlation function describes the correlation between fluctuating wind loads at two points in the frequency domain.Both domestic and international scholars have proposed various spatial correlation functions based on measured data.The Shiotani correlation function,adopted in Chinese specifications for wind load analysis and calculation,does not consider the influence of height.While practical for general transmission towers with low heights,it may underestimate the wind vibration coefficient for long-span towers.This paper analyzes and calculates towers of different heights using various correlation functions.The results show that,with increasing height,the wind vibration coefficient calculated by the Shiotani function is 3%to 11%lower in the tower head section and about 3%to 5.5%lower for the entire tower compared to correlation functions that consider height.Therefore,when designing long-span towers,it is recommended to appropriately account for the influence of height on the spatial correlation coefficient.