Study on Wind-Induced Response of Transmission Tower-Line System under Downburst Wind

Abstract

Downburst is the main source of extreme wind speed in non-typhoon areas, which has caused a large amount of transmission line damage all over the world. In order to reveal the wind-induced vibration response characteristics of a transmission tower-line system under downburst, the nonlinear dynamic analysis of a single tower and tower-line system is carried out, and the amplification effect of tower-line coupling and fluctuating wind on the dynamic response is studied. Then, the effects of three wind field parameters closely related to the average wind profile on the wind-induced response of the tower-line system are studied. The results show that under the action of the downburst, the tower-line coupling weakens the dynamic response to a certain extent, and the dynamic amplification factor of a single tower and tower-line system is 1.1 ~ 1.3; for the self-supporting tower, when the height of the peak wind speed is close to the height of tower, the responses of the structure are more unfavorable. When the vector superposition method is used, the storm moving speed (Vt) has little effect on the wind-induced response of the tower-line system. For large-span structures such as tower-line systems, to ensure the safety of the structural design, the value of the characteristic radius (Rc) should not be too small.