Prediction method development and precursory phenomenon extraction of landslide dam failure caused by piping

2016 Fiscal Year Final Research Report

• Project/Area Number: 24241061
• Research Category: Grant-in-Aid for Scientific Research (A)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Natural disaster science
• Research Institution: Shimane University
• Principal Investigator: Wang Fawu 島根大学, 総合理工学研究科, 教授 (10324097)
• Co-Investigator(Kenkyū-buntansha): 丸井 英明 新潟大学, 災害・復興科学研究所, 教授 (10219545) ; 志比 利秀 島根大学, 総合理工学研究科(研究院), 助教 (60311792) ; 小暮 哲也 島根大学, 総合理工学研究科(研究院), 助教 (70534006) ; 松本 健作 群馬大学, 大学院理工学府, 助教 (90302455) ; 酒井 哲弥 島根大学, 総合理工学研究科(研究院), 准教授 (90303809)
• Project Period (FY): 2012-04-01 – 2017-03-31
• Keywords: 土砂ダム / 決壊前兆 / 現地調査 / チェーン微動アレイ / 自然電位 / 模型実験 / 動水勾配 / 予測

Outline of Final Research Achievements

We proposed using microtremor chain array survey to detect the inner structure of landslide dam, and self-potential survey to find groundwater flowing path inside it. They were verified effective through field investigation in Higashi-Takezawa and Terano landslide dams, which were triggered by 2004 Chuetsu earthquake, Akatani and Kuridaira landslide dams, which were triggered by 2011 Kii Peninsula intensive rainfall, and Kel-tor giant landslide dam in Kyrgyz. Artificial landslide dam failure tests were conducted to investigate the failure process and the critical hydrodynamic condition to cause the piping and dam failure. It is found that critical hydraulic gradients for piping erosion and crest failure controlled the failure process. During the failure process, dam crest subsided, hydraulic gradient inside the landslide dam changed, and the turbidity of the water flowing out of the landslide dam suddenly changed. Those phenomena can be used to predict landslide dam failure.

Free Research Field

防災科学