EVALUATION OF IMPULSIVE EFFECT OF PULSE WAVE BY USE OF ENERGY INPUT TO STRUCTURES

Abstract

 By use of energy input to structure, a new definition of strong motion duration is proposed. On this basis, dynamic effects of pulse waves have been characterized with emphasis on the impulsive effects. Strong motion records observed at KiK-net Mashiki and Nishihara Village (The 2016 Kumamoto Earthquake) have short duration at each predominant period of the velocity response spectra. In long-period range, peak velocity response is reached in extremely short time and occurs almost simultaneously regardless of the period. As a result, velocity response spectra remain high and flat in wide range of long-period. Such impulsive effects are considered to be representative of the pulse waves. Considering both amplitude and duration, dynamic effects have been compared among various records. In long-period range, impulsive effects are found to be dominant in KiK-net Mashiki, Nishiharamura, K-NET Ojiya (the 2004 Niigata-ken Chuetsu Earthquake) and JMA Kobe (the 1995 Hyogo-ken Nambu Earthquake).