Abstract
There have been many accident reports of damage to transmission towers, such as member buckling caused by excessive load due to strong winds and/or foundation displacement due to ground deformations. In this study, we examined the progress of damages and the ultimate strength of transmission tower subjected to severe external loads using 3D finite element analysis, especially focusing on the distribution of damaged members and the accompanying strength degradation. We then performed repairing analysis of the damaged tower, which simulated repair measures by replacing damaged members and removing foundation displacement, and thereby evaluated the degree of strength recovery after the repair. The analysis result revealed that the efficacy of repair significantly depends not only on the repair methods but also on the distribution of damaged members associated with the cause of damage. This implies that the proper choice of repair measures according to the damage type is of crucial importance for effective repair to recover the tower strength. Finally, we examined the member forces after different repairing scenarios to elucidate the mechanical cause of the difference in the degree of strength recovery.
