Wind Tunnel Test on Wind Resistant Design of High-voltage Transmission Tower-line Coupling System

An aeroelastic wind tunnel test was carried out to study the rational wind resistant design method for high-voltage transmission tower-line coupling system. Two aeroelastic tower-line coupling system models were designed. One was composed of additional diaphragms in the section with the inconspicuous variable slope and the other was designed without additional diaphragm according to the current design code. The wind-induced responses in the turbulent flow were investigated through wind tunnel test.The wind-induced dynamic tower collapses were observed for the first time in the wind tunnel. Test results show that the failure characteristics in the wind tunnel are similar to those of the transmission tower failure on site caused by strong wind. The results also show that the wind-induced vibration of the system is strong spatial coupled nonlinear vibration ,and the effects of the wires and insulators vibration on the tower can not be ignored. The wind-induced vibration analysis of the transmission tower should consider higher-order mode effects whose contributions increase with the wind speed enhancement. The wind-induced failure of the transmission tower is related to the dynamic instability of the structure. Adding additional diaphragms can increase the wind resistant capacity of the transmission tower.