Abstract
Significant duration is a frequently-used duration index based on the time history of accumulated power of ground motions normalized to the total power. In this study, significant durations, D5-95, D5-75 and D75-95, defined for 5-95%, 5-75% and 75-95% of accumulated power, respectively, are evaluated for approximately 10,000 records of strong motions observed in major 35 earthquakes with Mw=5.0-9.0 which occurred from 1996 through 2013 in Japan. Accumulated power is calculated as Euclidean norm of the three components of acceleration processed with the frequency-domain filter used for calculation of JMA seismic intensity. On this basis, empirical equations for prediction of D5-95, D5-75 and D75-95 are developed as functions of such factors that are commonly employed for ground motion prediction equations. Proposed models are compared with existing ones, and the advantages of this study are addressed.
