In recent years

the strong seismic has caused serious threat to the normal operation of power system. Therefore

it is particularly essential to perform seismic analysis and assessment of key structures of the power system. In this paper

the seismic performance assessment of a transmission tower and the associated tower-line coupling system in a 220 kV high-voltage transmission line is performed. Firstly

The finite element model of the tower structure and tower-line coupling system is set up by using Abaqus software to analyze its dynamic performance

stress of the tower leg members

node displacement

and acceleration response. The influence of the conductor coupling on the dynamic of the transmission tower is obtained through comparing the dynamic performance and response peak of a single tower and tower-line system. The result shows that the fundamental frequency of the transmission tower in the coupled system is about 6%~9% lower than that of the single tower model and the structural fundamental frequency is reduced due to the existence of the conductor and ground wire. Due to the effect of the conductor and ground wire

the linear relationship between the peak seismic response of the tower and the peak motion acceleration becomes into a nonlinear relationship. Under the low intensity

the seismic response of the transmission tower in the tower-line coupled system is higher than that of the single tower model and

with the increase of intensity

the seismic response of the tower in the coupled system

compared to the single tower model

tends to gradually decrease. Both the node displacement peak and node absolute acceleration peak of the transmission tower in the tower-line coupled system are lower than those of the single tower model. In the vertical line direction

the nonlinear vibration damping effect of the conductor and ground wire is significantly stronger than its mass amplification effect.