Study on Amplification Effect of Vertical Seismic Motion of Osaka Basin Based on Strong Earthquake Records
Based on the Japanese KIK-net strong earthquake observation network,the horizontal and vertical components of S-wave and secondary wave in the Osaka Basin are separated in the paper.To study the relationship between vertical seismic motion and horizontal direction,the surface-to-borehole spectral ratio method is used.Research has shown that,although the amplification factor of the vertical component S-wave and the secondary wave in the basin is generally smaller than the horizontal component,the vertical seismic peak value of the vertical seismic motion at different depths of the basin is 2/3 of the maximum horizontal peak value in different periods,and the amplification factor of the vertical S-wave and secondary wave exceeds the seismic design,the influence of basin S-wave and secondary wave on vertical seismic motion in shallow soil layers is significantly greater than that in deep soil layers,and the influence gradually increases over long periods.
Osaka Basinsurface-to-borehole spectral ratio methodvertical seismic motionamplification factor