已建线路防覆冰倒塔改造措施探讨

通过对湖南2008年及2005年冰灾倒塔情况统计和调研,对杆塔倒塔具体形态特点及原因进行分析,提出已建线路防覆冰倒塔加强改造方案:对于平地丘陵线路,采用加塔方案,能有效提高线路整体抗冰能力;对于山地相对高耸、山区风道、垭口、抬升气流的迎风坡、较易覆冰等微地形区段,以及相对高差较大、连续上下山等局部地段杆塔,采用防覆冰能力更强的铁塔替换原塔,可有效缩小事故范围。

Discussion on Alteration Measures to Prevent Icing-Caused Tower Collapses in Existing Lines

Through statistics and surveys of collapsed towers in 2008＇ s and 2005 ＇s icing disasters, as well as analysis of specific characters and causes of collapsed towers, following strengthening schemes for preventing icing-caused tower collapse are proposed： to lines in plains or hills, adding towerswill effectively improve entire line＇s icing resistance; to sections with micro-topographies, such as high mountains, wind passages in mountain areas, narrow mountain pass, windward slope that raises airflow, prone to icing, etc., and to towers located in areas with large relative elevation and continuous up- and down-hills, replacing original one by a new one with better icing resistance, is a better choice, which can effectively reduce extent of an accident.