±800 kV特高压输电塔动力特性分析

Analysis of Dynamic Characteristics of±800 kV UHV Transmission Tower

针对在输电塔杆塔结构设计和动力特性的研究中难以通过理论分析和数值模拟准确获得塔身动力响应的问题,基于±800kV特高压直流输电工程直线塔,建立塔-线-基础体系有限元模型,采用p-y曲线法建立离散非线性弹簧模拟土体对结构的影响,对比分析了单塔、三塔两线、塔-线-基础体系等不同计算模型的特高压输电塔的动力特性,并与现场试验结果进行对比。结果表明,输电线的质量和刚度对输电塔的动力特性有一定的影响,塔线耦合作用不可忽略。考虑桩-土相互作用使输电塔自振频率降低。与单塔模型相比,塔-线-基础体系模型计算得到的频率相对较小,与实际测试频率更为接近,验证了塔-线-基础体系模型的合理性。

In the study of the structural design and dynamic characteristics of transmission tower structures,the accurate determination of the tower's dynamic response through theoretical analysis and numerical simulation poses a significant challenge.This paper focuses on the±800 kV Ultra-High Voltage Direct Current(UHVDC)transmission line towers and establishes a finite element model of the tower-line-foundation system.The p-y curve method is employed to represent the discrete nonlinear springs simulating soil-structure interaction.Different computational models,including single-tower,three-tower two-line,and the tower-line-foundation system,are compared and analyzed concerning the dynamic characteristics of UHV transmission towers.The study investigates the effects of the mass and stiffness of the transmission line on the tower's dynamic behavior,emphasizing the importance of considering tower-line coupling.The inclusion of pile-soil interaction results in a reduction in the natural frequency of the transmission tower.The tower-line-foundation system model yields frequencies that are relatively smaller compared to the single-tower model,and they are closer to the frequencies observed in field tests,validating the rationality of the tower-line-foundation system model.