| 講演要旨(和文) | | 本研究では，被災した，または被災が潜在している河川堤防の効果的な対策工の立案を可能にするために，堤防を物理探査により３次元的に可視化する装置と探査結果をもとに対策工設計の支援を行うシステムの開発を行ってきた．3年間の研究の最終年度である平成25年度には試作した可視化システムの評価を目的に実際の河川堤防で現場実証試験を実施した．堤防高8m，幅30mの堤防に，縦断方向に20m，横断30mの測定範囲を設定し，3次元電気探査と地震探査データの同時収録を行った．電気探査については3次元解析，地震探査については2次元トモグラフィ解析を行い，堤体の3次元画像を得た．さらに，電気探査による比抵抗と地震探査によるS波速度を用いて堤体の土質構成，透水係数，強度分布の推定を行い実データとの比較，検証を行った．その結果，対策設計に必要な照査断面の抽出や堤防のモデル物性設定に有効なデータを提供できることを確認した． |
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| | 講演要旨(英文) | | For effective design of a countermeasure for a damaged or potentially damaged river embankment, we have developed a design support system using a 3-D geophysical imaging of its interior. In the last year of three-year research term, the developed system was tested on an actual river embankment to evaluate its performance. 3-D electric and seismic data were simultaneously acquired in a 20m long and 30m wide measurement area on the 8m high and 30m wide embankment. The data were analyzed with 3-D electric inversion and 2-D seismic tomography techniques to get 3-D image of the levee body. Electrical resistivity and seismic S-wave velocity thus obtained were integratedly used in rock physical interpretation for estimating soil type, permeability and strength of the levee soil. The properties thus estimated were verified by comparing with real data measured in the river embankment. It was proven through this field test that the developed system can be a useful tool to effectively select the levee section for its safety verification and to estimate physical properties required for its seepage analysis. |
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