| 講演要旨(和文) | | 近年,都市部においては地下のインフラストラクチャの老朽化により,その上部に空洞が発生し,陥没事故などが生じている.都市部における土木物理探査は人工の振動や電磁気によるノイズによりS/Nが確保できず,探査性能を十分に発揮することができない.本研究では人口ノイズの影響を受けない探査手法として,宇宙線ミュー粒子を利用した地盤の密度分布を求める探査方法を検討した.予備的な検討として密度が均質な地盤中において宇宙線ミュー粒子の透過強度の理論計算を行った.計算の条件は,(1)土被りは5mから40m,(2)空洞の大きさは0.5mから4m,(3)空洞の中心の天頂角は0度,30度,60度である.計算の結果,土被りの10分の一程度までの大きさの空洞まで検出できることが確認できた.今後は測定機器の開発とジオトモグラフィ解析の開発を行う予定である. |
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| | 講演要旨(英文) | | It has been happened cave-in accidents in urban areas recently because of cavity occurrences above the decrepit underground infrastructures. Shallow geophysics for cavity explorations in the urban areas cannot show the sufficient performance because of the low S/N ratio by vibration or electromagnetic man-made noises. In this paper we have studied the geophysical exploration method using cosmic ray muons to avoid the man-made noises. Soil density is able to estimate from the muon intensity which is penetrated through the underground. We have conducted the theoretical calculations of the muon intensity in uniform soil preliminary. The calculating condition is as follows, 1. soil covering depths are set up from 5m to 40m, 2. cavity diameters are set up from 0.5m to 4m, 3. zenith angles of the cavities from the detector are set up from 0, 30 and 60 degrees. Cavity is able to detect until the one tenths diameters of soil covering depth using by cosmic ray muons intensity. We will consider the development of the detector and the geotomographic analysis. |
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