基于耐震时程法的输电塔抗震性能评估

Seismic Performance Evaluation of Transmission Tower Based on Endurance Time Method

为研究输电塔结构在地震作用下从弹性、弹塑性至倒塌过程中不同阶段的性能水平,建立两塔三线体系数值模型,提出了一种基于耐震时程法的极限性能易损性分析方法以全面评估输电塔的抗震性能。先用逐步增量动力分析方法评估耐震时程法的合理性,以位移系数作为极限损伤指标进行破坏等级划分,建立基于耐震时程法的概率模型进行易损性分析并获取不同地震强度下输电塔的超越概率。结果表明:耐震时程法能较好地预测不同地震强度下输电塔的响应,相对于IDA方法可以极大地提高结构的计算效率;9度地震烈度下该输电塔生命安全受影响的概率小于2%,表明该塔抗震性能较好。因此对输电塔进行抗震性能分析时可以采用耐震时程法以加快计算效率。

In order to study the performance level of transmission tower in different stages from elastic,elasticplastic to collapse under seismic action,the numerical model of two tower and three spans is established,a ultimate performance vulnerability analysis method based on Endurance Time Method(ETM)is proposed to comprehensively evaluate the seismic performance of transmission towers.First,the Incremental Dynamic Analysis(IDA)method is used to evaluate the rationality of the ETM,and the displacement coefficient is used as the limit damage index to classify the damage levels.Then,a probabilistic model based on ETM for vulnerability analysis is established and obtain the exceedance probabilities of transmission tower under different seismic intensities.The results show that the ETM can better predict the response of transmission tower under different seismic intensities,and it can greatly improve the calculation efficiency compared with IDA method.The probability that the life safety of the transmission tower is affected by 9 degrees seismic intensity is less than 2%,indicating that the tower has good seismic performance.Therefore,the ETM can be used to accelerate the calculation efficiency in the seismic performance analysis of transmission tower.