以参数分析为基础,对中、英、德双曲冷却塔结构设计规范风荷载标准值的取值原则和计算思路进行了对比,研究了基本风速、风剖面、内外表面静风风压环向分布、脉动效应系数、干扰效应系数等参数的取值和相互影响,并介绍了中、英、德双曲冷却塔设计规范与其荷载规范相关条款的差异;以3座不同高度的双曲冷却塔为例,对比分析了中、英、德规范的脉动效应系数取值,并对1座双曲冷却塔分别采用中、英、德规范计算等效风荷载标准值及其荷载效应。结果表明:受设计基本风压剖面和脉动效应系数控制,中、德规范的荷载标准值剖面较为接近,但明显小于英国规范;受荷载标准值剖面和环向压力分布影响,塔筒中下部区域子午向拉力和环向弯矩的极值分别对应于英、德规范,而喉部位置英国规范得到的子午向拉力和环向弯矩的极值分别为中、德规范的1.4倍和1.1倍。
Based on the comparative study of parameters,DL/T 5339—2006(China),BS 4485-4:1996(British),VGB-R 610Ue:2005(Germany) were selected as the representative codes and the calculation principles and methods of nominal value of wind load on hyperboloidal cooling tower were surveyed.The analysis considered the definition of basic wind velocity,wind profile,internal and external static wind pressure latitude distribution,gust effect factor,interference effect factor and also the interaction among them.Three representative hyperboloidal cooling towers were taken as examples to assess the gust effect factor from different codes,and a detail example was presented to illustrate the overall comparison of the nominal value of equivalent static wind load and the load effects.Results show that the nominal value profile of load of DL and VGB are close but much less than BS owning to differences from the design basic wind pressure profile and the gust effect factor.The meridian tension and latitude moment extreme values in middle-lower part of the shell originate from BS and VGB respectively;on the other hand,the meridian tension and latitude moment extreme values from BS are 1.4 times and 1.1 times of those from DL and VGB.