| 講演要旨(和文) | | 多くの農業用ため池が東日本大震災において被害を受けた。被災後の余震や豪雨は２次災害を起こす恐れがある。このような２次災害を防ぐため、亀裂の範囲を把握し、貯水位を低下させる必要があった。このため、亀裂への塩水注入前後に電気探査を実施し、比抵抗分布の差から亀裂範囲を推定した。その後の掘削調査により、推定された亀裂深度の妥当性を確認した。電気探査を利用したこのような調査法は、地震直後の亀裂調査に有効であると考えられる。 |
|
|
| | 講演要旨(英文) | | The 2011 off the Pacific coast of Tohoku Earthquake damaged many small earth dams. Aftershocks and heavy rain might cause further damage. Especially, it was necessary to understand the range of the crack to prevent such secondary disaster, and to decrease the reservoir water level. Therefore, we executed the electrical prospecting before and after the salt water injection into the crack, and presumed the range of the crack from the difference of the resistivity distribution. The validity of the presumption depth of cracks was confirmed by the subsequent digging investigation. It is thought that such an investigation method using the electrical prospecting is effective for the crack investigation immediately after the earthquake. |
|
|
|
| |
|