| 講演要旨(和文) | | 八甲田トンネルのルート周辺に点在する廃鉱内には,強酸性の鉱化汚染水(以下、酸性水と呼ぶ)が存在した.掘削に伴う水文環境の変化から,廃鉱内の酸性水が本坑内に流入する可能性があったため,トンネル切羽前方の地下水分布と挙動を把握できる調査法が必要とされた.そこで,本坑掘削時に適用する地下水調査法として,地山の比抵抗を探査する2種類の手法(周波数領域の電磁法と比抵抗法)に着目し,既設の調査坑を利用して,両手法の地下水分布と挙動に関する検知性能を評価した.その結果,水みちを形成する可能性の高い鉱脈や掘削に伴う地下水状況の変化に対し,両探査法が一定の検知性能を有することを確認した.ここでの知見をもとに,酸性水の坑内流入に対する調査,管理手法を定めて,大盛鉱山付近の本坑掘削に適用した. |
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| | 講演要旨(英文) | | The Hakkouda Tunnel, which passes near mine area, has a possibility that acid water including heavy metals flows into the tunnel. Therefore, it is important to infer distribution and behavior of groundwater ahead of tunnel face. In this study, we focused on frequency domain electromagnetic methods and electric resistivity method, and applied these methods to the hydrothermally altered rockmass related to mineralization. Then, it were evaluated that the abilities of these methods of detecting vein with the high possibility of forming a water pathway and change of the groundwater distribution with the excavation. As the results, it was confirmed that both methods had the ability of detecting the geological factor related to groundwater. |
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