A METHOD OF RESPONSE ANALYSIS OF TOWERS AND TRANSMISSION LINES SYSTEMS SUBJECTED TO EARTHQUAKES

This paper presents a method of response analysis of ultra-high-voltage towers subjected to earthquakes, taking into consideration the interaction between the towers and the transmission lines.Seismic responses of them are solved by the method of modal analysis using individual natural vibration characteristics of each tower and transmission line. This method has the advantages as follows: 1) The degrees of freedom remarkably decrease, as compared with those in the method applying the F. E. M. to the towers and the transmission lines. 2) This method can be applied, without difficulty, to the case where seismic waves differ at each foundation of tower and to the case where suspension towers are included. 3) The results obtained by this method are more accurate than those obtained by the method regarding the transmission lines as springs connecting the towers.