Investigations of damping constant used for seismic performance evaluation of steel pipe transmission towers during Level 2 earthquake ground motion

Abstract

After the 2011 off the Pacific coast of Tohoku Earthquake, contents for seismic assessment to transmission towers far exceed the assumption of past investigation. Limit state evaluation is required for the seismic assessment of transmission towers to Level 2 earthquake motion, and the importance of damping constant increases in evaluating seismic performance. The purpose of this paper is to investigate the equivalent damping constant used for seismic performance evaluation of transmission towers during Level 2 earthquake considering bolt slip. Furthermore, better arrangement of bolt slip characteristics to use bolt joint positively as kinetic-energy absorbing device is examined.