S波部分上下動、P波部分水平動のサイト増幅特性

Abstract

堆積層上で観測されるS波上下動やP波水平動部分がどのような波型(Wavetype)で構成されているかを分析するために, スペクトルインバージョンによるサイト特性の分離を行った.S波上下動の(相対的)サイト特性はP波上下動のそれに近く, 逆にP波水平動とS波水平動のサイト特性は似通った傾向を示し, S波上下動, P波水平動はそれぞれ観測点近傍でS波, P波で伝播している波で構成されていることが推察された.

In order to investigate the characteristics of vertical and horizontal comuponent of P- and S-wave parts, Iwata and Inkura (1986)'s method was applied to each component of each portion. Obtained for vertical component of P-wave parts, vertical component of S-wave parts, and horizontal component of S-wave parts are similar each other. Obtained site effect for vertical component of P-wave parts is close to that for vertical component of S-wave parts, and that for vertical component of P-wave parts is close to that for vertical component of S-wave parts for 1-20 Hz. These results show that vertical component of S-wave parts is what propagated as P-wave and hoiizontal component of P-wave parts is what propagated as S-wave in the sediment near the stations.