【作者】 熊卫红； 刘先珊； 李正良； 涂长庚； 李振柱；

【Author】 XIONG Weihong;LIU Xianshan;LI Zhengliang;TU Changgeng;LI Zhenzhu;Center China Grid Company Limited;School of Civil Engineering,Chongqing University;

【机构】 国家电网华中分部； 重庆大学土木工程学院；

【摘要】 高压输电线路具有杆塔高、跨度大及赋存环境复杂的特点,力学响应强非线性,其健康评估对把握电网运行状态至关重要。可靠度作为结构安全性的重要指标,逐渐发展为塔线体系安全评估的判据。文章以存在地质隐患的500k V张恩输电塔线体系为研究对象,以基础沉降及随机风荷载为影响因子,基于矩方法计算塔线体系的可靠度。采用梁单元及悬链线索单元对输电塔、导线和绝缘子进行模拟,建立塔线耦合体系的三维有限元模型,基于等效随机静风荷载模型,利用统计矩点估计法求解前四阶统计矩,计算塔线体系的可靠度。其结果表明基础沉降对杆塔可靠度影响较大,特别考虑随机风荷载作为不利荷载组合时,其可靠度降低,表现为轴压失效和偏压失效,与耐张塔的构件失效模式一致,说明可靠度分析方法的可行性。因此实际工程中,需结合输电线路的变形监测,深入研究地质灾害伴随的荷载随机性及变异性导致杆塔受力的不确定性,以更准确描述输电线路结构体系的可靠性和安全性。更多还原

【Abstract】 Due to the higher tower,long-span and complex environment of the high voltage transmission(hvt) line strongly with nonlinear mechanical response,so the healthy evaluation plays a significant role on understanding the operation conditions of the electric grid.Therefore,the reliability as the important index of the structure safety has gradually developed as the safety evaluation criterion of the tower-line system.Taking a 500 k V hvt line named Zhang-en as a case study and considering the leg settlement and the random wind as the combination loads,the system reliability has been analyzed based on the moment method.And the beam element and catenary cable element are used to model the transmission tower,conductors and insulators,and a 3-D finite element model(FEM) of the tower-line system is established.By using point estimate methods for probability moments,the reliability index are obtained based on a random equivalent static wind load.The results indicate that combination of the leg settlement greatly influences on the tower reliability,especially considering the random wind as the unfavorable load combination,the tower structure is with lower reliability and shows the axial compression failure and the eccentric compression failure,which is in accordance to the failure mode of the strain tower,the results also indicate the feasibility of the above method.Therefore,in the practical transmission lines,the uncertainty of the tower stress due to the load random and variation resulting from the geological hazards should be deeply investigated based on the online measuring,which can more correctly describe the reliability and the safety.更多还原