Failure Analysis on Transmission Tower Struck by Tropical Storms

Typhoon Mujigae struck the province of Guangdong in China which caused tremendous death and economic losses in October 2015. A large area was hit by a blackout for the tropical storm caused 206 power transmission lines to fail, among which 80 transmission towers collapsed. One typical collapsed tower hit by the storm was analyzed to estimate its ultimate bearing capacity and to find out the weak parts. After eigenvalue buckling analysis, dominant buckling mode was imposed on the tower as initial imperfection, then nonlinear buckling analysis was carried out to investigate the tower’s static load bearing capacity as well as the buckling members’ distribution. By applying dynamic wind loads to the tower-line coupled system, with stabilities of the members considered, to evaluate the tower’s dynamic load bearing capacity, and simulate the coupled system’s behavior. Results are well consistent with site investigation findings. Using the original design drawing, experimental research was carried out with the originally designed members to estimate the snap buckling limit point, and some retrofitting measures were suggested based on the findings of the analysis.