500kV输电塔结构抗冰加固改造方法试验研究  

Experimental Study on Retrofitting of 500 kV Transmission Tower Against Ice Load

作　　者：谢强[1] 孙力[1] 张勇[2] 

机构地区：[1]同济大学土木工程学院,上海市杨浦区200092 [2]华东电网有限公司,上海市黄浦区200002

出　　处：《中国电机工程学报》2011年第16期108-114,共7页Proceedings of the CSEE

基　　金：国家电网公司科技项目(2008-536);教育部霍英东教育基金会优选资助课题(114021)~~

摘　　要：为提高高压输电塔结构在覆冰荷载作用下的极限承载力,寻求有效的结构加固方法,以冰灾中破坏的典型500 kV输电塔为原型,制作了2对输电塔子结构模型,每对均由按原始结构形式设计和以增设横隔面方法进行加固改造的相应模型试件组成。对所有试件进行了模拟覆冰荷载作用下的静力加载试验,对比分析了结构受力过程、破坏模式和极限抗冰承载能力等,考察了增设横隔面对于提高结构受力性能的作用。基于有限元程序ANSYS,采用壳单元建立了加载塔段结构的实体模型,对试验全过程进行了模拟并与试验结果进行了比较。研究表明:横隔面的存在极大地降低了交叉斜撑的面外变形。无横隔面输电塔结构的破坏主要为主材的弯扭失稳,带横隔面结构破坏依然由主材构件的屈曲产生,但其屈曲模态由弯扭失稳趋向弯曲失稳。增设横隔面后,单、双塔段结构极限承载力的提高幅度分别达到了18.3%和17.6%。由于交叉斜撑面外变形对结构整体稳定的削弱效应得到抑制,主材角钢失稳模态中扭转效应对临界承载力的不利影响也被大幅降低,结构受力性能得到了全面提高。从而表明增设横隔面是一种合理有效地提高输电塔结构抗冰承载能力的加固方法。In order to develop an effective retrofitting scheme for increasing the load-carrying capacity of transmission tower against ice load, two pairs of subassemblages for power transmission tower were established based on a typical 500kV transmission towcr which was severely damaged during the ice disaster. Each pair was designed with current code; while an additional diaphragm was added to its counterpart as a measure of retrofitting. The comparative tests on mechanical behavior, failure pattern and ice load-carrying capacity of the structures were conducted. The favorable effect of adding diaphragm in terms of improving structural performance of tower subassemblages was investigated. FEM software ANSYS was employed to analyze the behavior of the subasscmblagcs by using shell elements. The study revealed that after adding diaphragm the out-of-plane deformation in the joints of cross-bracings was reduced significantly. Buckling mode of the main membcr was transited from torsional-flexural buckling to flexural buckling. And for one-panel and two-panel tower subasscrnblagcs, the ultimate strength was increased by 18.3% and 17.6% respectively. The diaphragm comprehensively improved the mechanical performance of transmission tower structures by decreasing the unfavorable influence of torsion of main member, and together with inhibiting the out-of-plane deformation of diagonal braces. Adding diaphragm is an effective and practical retrofitting method for enhancing the ice load-carrying capacity of transmission tower stnuctures.

关 键 词：输电塔 覆冰荷载:横隔面:加固 静力试验:有限元分析 破坏模式 

分 类 号：TM75[电气工程—电力系统及自动化]