著者

谷井 敬春 廣田 政矢 菊地 裕一 釜谷 薫幸 高橋 浩

出版者

Japan Society of Civil Engineers

雑誌

トンネル工学研究発表会論文・報告集 (ISSN:18849091)

巻号頁・発行日

vol.12, pp.297-302, 2002

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A large-scale collapse occurred when the face reached about 900m point from the east portal. Soil from collapse containing cobble gravels became an avalanche with a large amount of water, and has surged to the portal. Ground surface of 130m from collapse point was caving like Crater. These was no human damage and a little material damage though it was such a huge disaster. Countermeasures are as follows, caving area was restored with air-mortar, boring was done for drainage from the tunnel, grouting was done right under the collapse area. The tunneling work was completed from the record-breaking collapse two years later.