断线张力反向对轻中冰区悬垂塔受力影响的研究

Study on the Influence of Reverse Disconnection Tension on the Mechanical Properties of Suspension Tower in Light and Medium Ice Area

依据结构力学理论推导了反向断线荷载的作用机制,其主要控制轻中冰区悬垂塔横担下平面斜材、横担外轮廓材和塔身斜材;选取某特高压直流线路工程的轻中冰区悬垂塔,结合数值模拟分析论证了理论推导的有效性和可靠性。数值模拟计算表明,反向断线对横担下平面斜材的影响显著,反向断线时横担下平面斜材的内力比正向断线的内力增大31%左右,横担轮廓材和塔身侧面斜材的内力比正向断线要大,但增大效应相对较小,在10%左右;同时,塔身正面斜材可能受正向断线或反向断线控制,与铁塔形式和挂线方式有关。因此,工程设计中轻中冰区悬垂塔需要考虑反向断线的工况,否则是偏于不安全的,研究结论已应用于工程实践中。

According to the theory of structural mechanics,the action mechanism of reverse disconnection load is deduced,which mainly controls the plane slanting material under the cross arm,the outer contour material of the cross arm and the slanting material of the tower body of the suspension tower in the light and medium ice area.The effectiveness and reliability of the theoretical derivation are verified by selecting the suspension tower in the light and medium ice area of an UHVDC line project,combined with the numerical simulation analysis.Numerical simulation results show that,the effect of reverse disconnection on plane slanting material under cross arm is significant,the internal force of plane slanting material under the cross arm is about 31% higher than that of the forward disconnection.In the state of reverse disconnection,the internal force of cross arm contour material and the slanting material of the tower body side is also larger than that of the forward disconnection,but the increasing effect is relatively small,about 10%.At the same time,the front slanting material of the tower body may be controlled by forward or reverse disconnection,which is related to the tower type and hanging mode of the wire.Therefore,it is necessary to consider the condition of reverse disconnection in engineering design of suspension tower in light and medium ice area,otherwise it is unsafe.The research conclusion has been applied in engineering practice.