The Effect of Soil-Structure Interaction on Vibration Reliability of Transmission Line

Abstract

Since the main material of the plug-in foundation transmission tower legs is directly connected to the foundation, the traditional reliability calculation method is no longer accurate. For this reason, this paper considers the soil-structure interaction between the foundation soil and the tower legs, replaces the upper limit of the natural circular frequency and frequency ratio of the original iron tower with the corresponding value after considering the SSI (Soil-Structure Interaction), and proposes a SSI-based insertion Analysis method of vibration reliability of type foundation iron tower. First, perform modal analysis to obtain the natural circular frequency of the tower considering SSI; then, according to the external load of the tower under the icing of the wire and the vibration displacement equation of the tower considering SSI, the expression of the comprehensive amplitude amplification factor of the tower is derived, and then the consideration is obtained. The upper limit value of the frequency ratio of SSI and the functional function; finally combined with the normal distribution to solve the problem, the vibration reliability of the plug-in foundation tower considering SSI is obtained. The proposed method has been applied in the analysis of a galloping accident on a line in Guangdong Province. The maximum reliability of the damaged 6-base plug-in foundation tower obtained by this method is 0.9713, which is less than the target reliability of 0.9993.