[S-SS25] Strong Ground Motion and Earthquake Disaster

[SSS25-P20] A study for detection of the site on inclined engineering bedrock based on microtremor observation

*Kimitoshi SAKAI¹, Kohei TANAKA¹, Atsuhiro USAMI¹, Kaoru KOBAYASHI², Masaya HIRABAYASHI² (1.Railway Technical Research Institute, 2.East Japan Railway Company)

Keywords:microtremor, surface wave, irregular ground

The local site amplification is seen in the ground motion observed at site on inclined engineering bedrock. So, the site is the important point from the view of the seismic design. In this study, the feasibility of detection of the site on inclined engineering bedrock based on microtremor observation is verified. As the result, the ratio of vertical Fourier spectrum between two point shows the harmonic tendency of the degree of the slope of the engineering bedrock.