台风载荷作用下输电塔线体系时程分析及补强措施

为研究±800 kV输电线路所使用的横担较长的铁塔在受到台风载荷作用时的时程响应分析,通过建立三塔两线有限元模型,基于风速不随高度变化的Von Karman谱,利用谐波叠加法生成了基准风速为50 m/s的风速时程,应用模拟的台风载荷进行时长为50 s的时程分析,共分析了风载荷45°、60°、90°作用下塔线体系的三种情况。仿真结果显示,在45°和60°风作用下,铁塔中部、塔头和塔身连接的平口处应力超过屈服强度,导、地线挂线板处所受应力也超限,铁塔在90°风作用时,塔身腰部主材和塔腿主材应力也超过屈服强度。要预防台风对铁塔的破坏,应该从上述三个部位对铁塔进行补强,在塔腿及塔腰之间增加水平材是一种有效的加固措施。

Time history Analysis and Strengthening Technique of Transmission tower-line system Under Typhoon Load

In order to study the time history response of a tower with a long cross-bearing used in (±800kV) transmission lines un-der typhoon loads, a three-tower two-line finite element model is established. Based on the Von Karman spectrum of wind speed which does not vary with height, the wind speed time history with a reference wind speed of 50m/s is gener-ated by the harmonic superposition method as a simulated typhoon load. The time history analysis of the tower-line sys-tem with wind load of 45 degrees, 60 degrees and 90 degrees is carried out. The simulation results show that under the action of 45 degrees and 60 degrees wind, the stress at the flat junction of the central part of the tower, the head of the tower and the tower body exceeds the yield strength, and the stress at the conductor and the ground wire hanging plate also exceeds the limit. When the tower is under the action of 90 degrees wind, the stress of the main material at the waist of the tower body and the main material at the leg of the tower also exceeds the yield strength. To prevent the damage of typhoon to the tower, the tower should be reinforced from the above three parts. It is an effective reinforcement measure to add horizontal material between tower leg and tower waist.