基于点估计法的杆塔结构平均可靠度分析  

Average Reliability Analysis of Transmission Tower Structure Based on Point Estimation Method

作　　者：黄兴 田雷[2] 杨洋 廖邢军 蒲凡 李钟 HUANG Xing;TIAN Lei;YANG Yang;LIAO Xingjun;PU Fan;LI Zhong(Southwest Electric Power Design Institute Co.,Ltd.,Chengdu 610021,China;State Power Economic Research Institute,Beijing 102209,China)

机构地区：[1]西南电力设计院有限公司,四川成都610021 [2]国网北京经济技术研究院,北京102209

出　　处：《电力工程技术》2018年第2期127-131,共5页Electric Power Engineering Technology

基　　金：国家电网有限公司科技项目(SGTYHT/14-JS-88)

摘　　要：由于目前输电塔结构设计规范参照建筑结构规范编制,所涵盖的设计对象大多针对荷载效应比不大于3的情况。然而,输电塔自重轻,活荷载效应比普遍较高,导致其按照现有规范进行设计的构件可靠度水准降低。为了校准输电塔的可靠度水平,文中首次尝试将荷载效应比视为随机变量,沿用点估计法的基本思想,以荷载效应比的分布为输入,得到基于荷载效应比分布的、具有统计意义的杆塔结构加权平均可靠度指标。首先,通过大量实际结构分析得到杆塔结构构件风荷载效应比的样本值,基于这些样本值进行分布拟合,得到荷载效应比的分布;其次,利用点估计法基本思想,选取荷载效应比分布的积分点,计算这些积分点处的可靠度指标,再根据各对应积分点的权重值,得到平均可靠度指标。最后,文中分别计算了不同风速下,不同线条风占比和不同结构重要性系数下的平均可靠度指标。At present,the codes of transmission towers are almost based on the construction of building codes,and the design objects are mostly aimed at the load-effect ratio not greater than 3.However,the living load effect of the transmission towers is higher than that of the existing codes,and the reliability of the components is reduced.In order to calibrate the reliability level of transmission towers,regarding the load-effect ratio as a random variable based on the point estimation method is firsly attempted,the weighted average reliability index of tower structure is obtained based on the distribution of load effect ratio as input.Firstly,the samples of wind load-effect ratio of tower structural members are obtained through a large number of structural analyses,and the distribution fitting is exploited to fit the distribution of load effect ratio.Secondly,applying the point estimation method,the abscissas of the fitted load-effect ratio distribution are selected,the reliability index of these points is calculated,and then the average reliability index according to the weight of each corresponding point.At last,the average reliability index under different wind speed and different structure importance coefficients is calculated.

关 键 词：输电塔杆塔结构 构件可靠度 点估计法 分布拟合 平均可靠指标 

分 类 号：TH212[机械工程—机械制造及自动化] TH213.3