高压输电线路覆冰倒塔非线性屈曲分析

本文以湖南地区挂靖线220KV输电线路覆冰倒塔为例，按原工程资料建立精细化输电塔-线体系有限元模型。依据三峡地区覆冰资料建立覆冰增长曲线，考虑水平垂直档距、高差、不均匀覆冰和风荷载影响，对覆冰和风荷载作用下输电塔-线体系进行非线性屈曲分析，计算出覆冰荷载以及风荷载与覆冰共同作用下输电塔结构的极限承载能力，分析了倒塔的主要原因。研究表明，过载和不均匀覆冰引起的不平衡张力以及风荷载是倒塔的主要原因,重冰区覆冰架空输电线路技术设计规程的荷载水平需要进一步提高。

Nonlinear buckling analysis of collapsed steel tower for 220kV Guajing Iced transmission line

In this paper, based on the principle of collapsed steel tower design for Guajing transmission line, the finite element model of multi-tower-line coupled system has been established according to the original data of engineering. The curve of ice increasing with time has been given according to the data of icing record. Considering the high deference, ice increasing, asymmetry between ices of conductors and wind load, nonlinear buckling analysis of transmission tower-line system under ice load and wind load has been carried out. The ultimate load of tower structure has been studied by using nonlinear buckling analysis and the cause of the tower falling down is analyzed in this paper. It can be concluded that wind load and unbalanced tension caused by overload and asymmetry between ices of conductors are the main reasons why the steel towers fell down, and technical code of design overhead transmission line in heavy icing area needs to be modified.