摘要
大跨越输电塔线体系兼具大跨、高耸、柔性等特点,对风荷载异常敏感,且由于输电线、绝缘子与跨越塔的耦合作用,其动力特性和风致响应较为复杂。以在建的世界最高500 kV长江大跨越工程为例,基于ABAQUS建立了单塔和塔线体系的有限元模型,研究了单塔和塔线体系的动力特性,并依据风荷载时程分析结果分析了该体系的风致响应和风振系数。研究结果表明:塔线体系跨越塔自振频率小于单塔;不同风攻角下塔线体系跨越塔顶点位移均大于单塔,加速度响应则小于单塔;现行电力规范计算风振系数加权平均值大于时程分析结果,偏于安全,但在主材混凝土灌注区段风荷载可能会被低估,同时规范未考虑到横担处质量和外形的变化导致风振系数的突变。
The long-span transmission tower-line system combines the characteristics of long-span, towering and flexibility, which is extremely sensitive to wind loads. Due to the coupling of the transmission wires, insulators and the spanning tower, its dynamic characteristics and wind-induced response are more complex. Taking the world’s tallest 500 kV transmission tower crossing the Yangtze River as an example, finite element models of single tower and tower-line system were established based on ABAQUS. The dynamic characteristics of single tower and tower-line systems were studied, and wind-induced vibration response together with wind-induced vibration coefficients were analyzed based on the results of wind load time-history analysis. The results showed the natural vibration frequency of the tower in transmission tower line system was less than that of single tower. Under different wind attack angles, the displacement of the tower line system at the apex of the tower was larger than that of a single tower, and the acceleration response was smaller.The weighted average value of wind-vibration coefficient calculated in the current code was greater than the time-history analysis results, which was partial to safety. However, the wind load in the concrete pouring area of main stressed tube might be underestimated, and the sudden change of wind-vibration coefficients caused by the change of mass and shape at the cross arm was not considered.
作者
罗柯镕
余亮
舒赣平
李布辉
宁帅朋
LUO Kerong;YU Liang;SHU Ganping;LI Buhui;NING Shuaipeng(The Key Laboratory of Concrete and Prestressed Concrete Structures of the Ministry of Education,Nanjing 211189,China;School of Civil Engineering,Southeast University,Nanjing 211189,China;Jiangsu Power Design Institute Co.,Ltd.of CEEC,Nanjing 211102,China)
出处
《工业建筑》
CSCD
北大核心
2022年第8期1-8,共8页
Industrial Construction
关键词
大跨越
塔线体系
风致响应
风振系数
long-span
tower-line system
wind-induced response
wind-induced vibration coefficient
