台风等效静风荷载作用下输电塔线体系极限承载力分析

Ultimate Bearing Capacity Analysis of Transmission Tower-line System under Equivalent Static Typhoon Wind Load

台风引起的输电线路破坏情况屡有发生,为了研究台风作用下输电塔线体系的极限承载力,以实际发生倒塔事故的广东省某220 kV输电线路的塔-线体系为研究对象,结合台风风剖面和规范中的方法确定塔线体系的等效静力风荷载,考虑输电塔结构的材料非线性和几何非线性特征,通过有限元软件ANSYS在逐级加载条件下分析输电塔线体系的极限承载力,研究风向角、相邻塔的变形、导地线张力的变化对极限承载力的影响。结果表明:(1)通过逐级加载的方式可以较为方便的找到不同工况的极限荷载,确定出结构的最不利风向角;(2)塔线体系模型的选取会较大的影响计算结果,应尽量接近真实情况的选取模型,从而得到更为准确的分析结果;(3)导地线初始张力可以一定程度上提高输电塔线体系的极限承载力,在条件允许的情况下可以适当增加导地线的初始张力。

The damage of transmission line caused by typhoon occurred frequently. In order to study the ultimate bearing capacity of transmission tower line system under typhoon load,the transmission tower-line system of a 220 kV transmission line in Guangdong Province is taken as the example in this article,that many towers was collapsed in a typhoon. The equivalent static wind load of the tower-line system is calculated by combining a recommended typhoon wind profile and the wind load calculation method of Chinese Load Code. The nonlinear of material and geometric characteristics of the tower is considered,and the ultimate bearing capacity of the transmission tower-line system is analyzed under step-loading by ANSYS. The influence on the ultimate bearing capacity caused by the wind directions,the deformation of adjacent towers,and the tension of the line is studied. The analysis results show that:1)the ultimate bearing capacity of the transmission tower-line system and the most dangerous condition can be obtained by step-by-step upgrade analysis. 2)Finite element modal of tower-line system will influence the results the ultimate bearing capacity calculation. Taking more towers into the finite element modal will get more accurate result. 3)Choosing higher allowable initial force is benefit because the ultimate bearing capacity of the transmission tower-line system will increase with the initial tension of the line to some extent.