Tower Destruction Mechanics of Overhead Transmission Lines and Prevention Technologies in Ice Disasters

Some advances on tower destruction mechanics of overhead transmission lines and prevention technologies in ice disasters are introduced. First, based on the numerical and experimental study on the tower-line system with ice-shedding and broken conductors, dynamic responses of the tower-line system were obtained and the unbalanced tensions, as well as the uplift loads, were proposed. Secondly, study on the bearing capacity of K-type joints with an included angle less than 30 degrees was completed. The first ultra-high voltage (UHV) steel tubular cup type tower in the world was designed for transmission lines in heavy icing areas, and the prototype test was carried out in the UHV tower test station. Thirdly, the bearing capacity and the destruction modes of transmission towers with galloping conductors were studied. A practical calculation method of the galloping loads was obtained. A constructional measure realized by the bolt strengthening technology was proposed for the transmission towers in the galloping area with high intensity. Lastly, the structural reinforcement technologies of the transmission towers after ice disaster were developed, especially for the enhancement of design standards and reinforcement technology for main members of transmission towers.