Study on the collapse of a transmission tower-line system under severe convective weather and the combined coefficients of wind and rain
Extreme weather events pose a significant threat to the operation of transmission lines.Steel lattice transmission towers of relatively low voltage levels experience a higher frequency of collapse incidents.This study employs a phenomenological nonlinear hysteretic model to investigate the collapse behavior of transmission tower-line systems under severe convective weather.The influence of rain loads on the response of transmission towers is summarized.Based on the records of wind and rain meteorology,a wind-rain combination analysis was conducted,and wind-rain combination coefficients were proposed.The results indicated that during extreme severe convective weather,the vulnerable parts of the studied transmission tower were mainly the 3rd and 4th sections.The extensive buckling of diagonal members and limited buckling of main members in this area were the main reasons for the collapse of the transmission tower.Under extreme wind and rain meteorological conditions,it is necessary to consider the influence of rain load on the response of the transmission tower-line system.Under different return periods,the combined values of wind speed and rainfall are both lower than their respective threshold values.The recommended values for the combined coefficient under a 50-year return period in this area are 1.0 for wind speed and 0.7 for rainfall.
wind and rain loadsnonlinear hysteretic model of angle steelcollapse failuredynamic analysiscombination coefficient
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