A STUDY ON THE CORRELATION BETWEEN GROUND VIBRATION CHARACTERISTIC AND DAMAGE LEVEL OF STRUCTURES AT MASHIKI TOWN BY THE 2016 KUMAMOTO EARTHQUAKE

Abstract

 The 2016 Kumamoto Earthquake caused severe damage on structures such as houses at Mashiki Town in Kumamoto Prefecture. Authors conducted microtremor observation at various sites in Mashiki Town in order to discuss the relationship between ground condition and damage level of structures. H/V spectra and phase velocities were evaluated from the microtremor records and average S-wave velocities were also evaluated from the phase velocities. It was found that both peak frequencies and average S-wave velocities are low at most of the sites where structures were severely damaged. Site amplification factors at some sites were evaluated from the aftershock records obtained during microtremor observation.