采动区输电塔线体系在地表水平变形和边界层风作用下的承载性能及安全性评价

BEARING PERFORMANCES AND SAFETY ASSESSMENT OF TRANSMISSION TOWER-LINE SYSTEMS IN MINING AREAS UNDER SURFACE HORIZONTAL DEFORMATION AND BOUNDARY LAYER WIND

以位于采动区的典型220 kV输电塔线体系为研究对象,运用ANSYS软件建立了塔线体系的有限元模型,研究了不同方向的边界层风作用下的铁塔控制点的位移时程、关键斜向支撑构件和主要受力构件的应力时程,分析了地表水平变形方向、变形程度大小以及边界层风的风向角与铁塔关键主要受力构件的最大等效应力的相关关系。结果表明:在地表水平变形和边界层风作用下,主要受力构件是决定铁塔抗地表变形和抗风安全性的关键杆件;铁塔位移控制点的位移在正常运行的允许范围内;地表水平变形的最不利作用方向是30°;边界层风的最不利作用方向是30°和45°;铁塔主要受力构件最大等效应力和地表变形的大小之间存在着线性关系。在此基础上,得到了输电铁塔主要受力构件最大等效应力和地表水平变形方向、水平变形程度的相关关系,提出了一种采动区输电线路在地表水平变形和边界层风作用下的安全性评估方法。

Taking a typical 220 kV transmission tower-line system located in the mining area as the research object, the finite element model of the tower-line system was constructed by ANSYS software. The displacement time history of the control points of the tower and the stress time history of key crossed bracing members and tower legs under the action of boundary layer wind in different directions were studied. The relations between the maximum equivalent stress of legs of the tower and the surface horizontal deformation direction, the deformation degree, and the wind direction angle of boundary layer were analyzed. The results showed that the four leg members were the key members to determine the safety of tower against surface deformation and wind under the action of surface horizontal deformation and boundary layer wind. The displacement of the tower displacement control points were within the allowable range of normal operation. The most unfavorable action direction of surface horizontal deformation was 30°. The most unfavorable directions of boundary layer wind were 30° and 45°. There was a linear relation between the maximum equivalent stress of leg members of the tower and the degree of surface deformation. On this basis, the correlations between the maximum equivalent stress of leg members of the tower and the direction and degree of surface horizontal deformation were obtained, and a safety assessment method of the transmission tower-line system in mining area under the action of surface horizontal deformation and boundary layer wind was proposed.