覆冰、风荷载作用下南方某输电铁塔可靠度分析  

Reliability analysis of a transmission tower in South China under ice load and wind load

作　　者：熊铁华[1] 侯建国[1] 安旭文[1] 

机构地区：[1]武汉大学土木建筑工程学院,湖北武汉430072

出　　处：《武汉大学学报（工学版）》2011年第2期207-210,265,共5页Engineering Journal of Wuhan University

基　　金：国家自然科学基金资助项目(编号:51078296)

摘　　要：对2008年年初由于冰雪天气发生倒塌的南方某输电铁塔的构件可靠度进行了分析.以覆冰厚度、覆冰时的风速以及材料的强度为基本随机变量,用响应面法来模拟我国杆塔设计技术规定中梁单元的极限状态方程,它是随机变量的解析表达式.然后利用几何法来计算每个梁单元的可靠度指标,计算结果显示,在结构设计条件下,该输电铁塔单元可靠性较低;如果再考虑由于导线、地线的不均匀覆冰所引起的不平衡张力,铁塔某些薄弱处的可靠度指标相当小,塔具有相当大的失效风险.计算结果与事故原因分析结论是相吻合的.Reliability of a transmission tower broken down in the beginning of 2008 because of ice weather in south China is analyzed.Ice thickness,wind velocity and material resistance are selected to be as basic random variables.Limit state functions of beam elements from Chinese technical regulation of design for tower and pole structures are substituted by approximate ones simulated by response surface approach.These approximate functions are apparent expressions about basic random variables and then reliability indices of the beam elements are evaluated by geometric method.The numerical examples indicate that reliability index values of some elements are small under design condition,and if wires unbalance tension which are caused by wires icing uneven existed;reliability index values of some elements in tower certain weaknesses are very small and the tower would mostly be failed.The causes of the accident analysis results coincide with the conclusions given by the accident investigation report.

关 键 词：输电铁塔 可靠度分析 响应面法 覆冰荷载 几何法 

分 类 号：TB114.3[理学—概率论与数理统计]