地下深部で活断層の破砕帯を同定する調査手法の検討

Examination of the investigation technique which identifies the crush zone of an active fault in the deep underground

野原 壯   ; 丹羽 正和   ; 安江 健一; 島田 耕史   

Nohara, Tsuyoshi; Niwa, Masakazu; Yasue, Kenichi; Shimada, Koji

本研究では、断層の累積変位量と破砕帯の幅の関係を用いて、トンネルのデータを踏まえた地下深部における活断層の破砕帯を把握する調査手法を検討した。トンネルで行われたボーリングのデータから、変位が集中した活断層の破砕帯の位置を特定した。その破砕帯の幅の大きさは、累積変位量との関係から推定したそれと一致した。本研究の結果、地層の変位,断層粘土の発達状況及び条線の方向から、活断層の破砕帯を特定できる可能性が示された。

This research examined the investigation technique which grasps the crush zone of the active fault in the deep underground based on the data of the tunnel using the relation between the amount of accumulation displacement of a dislocation, and the width of a crush zone. From the data of drilling performed in the tunnel, the position of the crush zone of the active fault which displacement concentrated was pinpointed. The size of the width of the crush zone was in agreement with it which was presumed from the relation with the amount of accumulation displacement. A possibility that the crush zone of an active fault could be specified was shown from displacement of a stratum, the development situation of fault clay, and the trend of striation as a result of this research.