| 講演要旨(和文) | | 開削が予定されていた河川堤防において，堤体内部物性構造の把握を目的とした統合物理探査を実施した．開削前には，従来の統合物理探査に加え，比抵抗トモグラフィ探査およびS波トモグラフィ探査を実施した．またCPTを補足的に実施している．開削後には比抵抗マッピングおよび小間隔表面波探査を実施した．探査の目的は，堤体内部物性構造探査としてのトモグラフィ探査手法の構造分解能および再現性を検討すること，小間隔表面波探査の作業性を評価することであった．開削前探査の結果，縦断方向探査断面とトモグラフィ探査による横断探査断面は概ね整合的であった．開削後の比抵抗マッピングおよび小間隔表面波探査によって，堤体内部の物性分布を明瞭にマッピングすることができた．この比較探査結果は，従来の縦断方向の統合物理探査の検証に加えて内部物性構造把握にも，横断方向のトモグラフィ探査ならびにCPTが有用であることを示している． |
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| | 講演要旨(英文) | | Integrated geophysical surveying was conducted on a levee system part of which was to be excavated for the repair of an existing deteriorated sluice. S-wave and resistivity tomography surveys across the levee body were applied as well as the conventional integrated geophysical surveying. Tomography sections clearly delineated stacked structure in the levee body. CPTs were also conducted before the excavation. After the excavation, surface resistivity mapping and short-spacing surface wave survey were carried out so as to obtain ground truthing data. The stacked structure and its geophysical correspondence in the levee body were directly identified by the measurements. The comparative measurements before and after the excavation showed the usefulness of tomographic method as ground truthing tool. CPT and SCPT were also helpful to acquire detailed ground truth data in levee systems. |
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