ASSESSMENT OF THE EFFECT OF THE INPUT GROUND MOTION INTENSITY ON THE DYNAMIC BEHAVIOR OF TV POLES ON BRIDGES

Abstract

 In evaluating the seismic performance of columnar attached structures installed on bridges, the sensitivity to resonance will differ depending on the amount of plasticity of the bridge. Due to the natural period shift caused by yielding, the response of the columnar structure can be decreased as the ground motion input increases. In this study, using a TV pole installed on a bridge pier as an example, the relationship between the input ground motion intensity and the dynamic response amplitude of the TV poles is investigated by means of the incremental dynamic analysis (IDA), focusing on the possibility of unconservative seismic response assessment using nonlinear time history analysis. As a result, it was confirmed that for the target structure and input waves, when the bridge pier becomes significantly plastic and the natural period becomes long, the relationship between the magnitude of the input earthquake motion and the response of the TV pole is reversed.