Relationship between Peak Ground Acceleration, JMA Seismic Intensity and Characteristics of Earthquake Motion Spectra During the 2011 off the Pacific Coast of Tohoku Earthquake

Abstract

The applicability of peak acceleration ratio that has been proposed by authors as an index for characteristics of earthquake spectrum is verified by using earthquake motion records obtained during the 2011 off the Pacific coast of Tohoku Earthquake. We also try to use the peak acceleration ratio for evaluation of response of wooden houses. A relationship between the peak acceleration ratio and amplitude characteristics of Fourier spectrum of earthquake ground motion is estimated at observation sites with JMA seismic intensity of more than 5-. As a result, the ratio is useful to estimate an index of earthquake ground motion with a period range between 1 and 2s. Moreover, a relation between the peak acceleration ratio and drift angle of wooden houses evaluated by an equivalent-performance response spectrum is also examined. A good correlation is shown in case of 0.3 and 0.5 of the base shear coefficients of wooden houses.