| 講演要旨(和文) | | 鳥取市街地には埋め立てられた鳥取城の堀跡が存在し，その埋積物は軟弱だと想定できる．さらに，対象地域の堀の深さはボーリングデータなどから数メートルと想定される．そこで，本研究では常時微動を用いた3成分単点観測と半径0.3mからのアレー観測を実施して堀跡の位置推定を行い，それが微動特性に与える影響について検討を行った．その結果，Vs=80m/s，層厚3mという堀跡が推定でき，その影響でH/Vの周期0.2秒付近に2次卓越周期が現れることが分かった． |
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| | 講演要旨(英文) | | Tottori City is an old castle town and there are moat marks buried by soft soil deposits. Depths of the moats are estimated to be several meters from boring data and ancient writings. We carried out microtremor observation to estimate the location of the buried moats and to examine effect of the soft soil deposits on ground motions. We found soft soil layer with 3 meters thickness and shear wave velocity 80 m/s from array observation at the point where old moat is buried. We also found the theoretical H/V spectral ratio from buried moat model has second dominant period around 0.2 seconds, and it is verified by observed H/V spectral ratios . |
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