基于±800 kV特高压直流输电线路的中美规范风荷载对比研究

Comparative Study on Wind Load Between Chinese and American Codes Based on ±800 kV UHV DC Transmission Line

针对±800 kV特高压直流输电线路设计的中美标准,从结构重要性系数、分项系数、重现期等方面对风荷载进行全面探讨分析,并深入研究基本风速、地形地貌和高度影响因素、风载体型系数以及动力特性的取值方法。结合典型±800 kV特高压直流输变电工程,将中美规范的风荷载进行对比分析,得出美国规范的线条风荷载和塔身风荷载标准值均高于中国规范,但线条风荷载设计值小于中国规范30%左右,塔身风荷载总设计值(各风压段之和)与中国规范基本相等。结合典型杆塔计算分析,发现美国规范的风荷载整体设计水平低于中国规范约23%。

This article mainly studied the Chinese and American design codes of ±800 kV UHV transmission line,which refers to the analyzes of wind load comprehensively from the aspects of importance coefficient,partial coefficient,MRI and design condition.Meanwhile,the basic wind speed,topography and height factors,wind load shape coefficient and dynamic characteristics are intensive studied.Then compared the Chinese codes with American codes of wind load calculation based on the typical ±800 kV UHV transmission project,the wind load of wire and tower body in the American code are higher than those in the Chinese code,but the design value of line wind load is less than about 30%of that in the Chinese code.The total design value of tower body wind load(the sum of all wind pressure sections)is basically the same as that in the Chinese code.Combined with the calculation and analysis of typical tower,it is found that the overall design level of wind load in the American code is about 23% lower than that in the Chinese code.