Layered internal structure and breaching risk assessment of the Higashi-Takezawa landslide dam in Niigata, Japan

摘要: The internal structure and geotechnical properties of landslide dams have rarely been examined in detail, although they largely control the longevity potential failure mechanisms dams. During 2004 Mid-Niigata Prefecture earthquake, thousands landslides were triggered many formed Imo River basin. Among these dams, biggest one that occurred Higashi-Takezawa district threatened both upstream downstream areas. Emergency eventual permanent countermeasures successfully performed to mitigate hazards presented by dam. preserved dam provides a good field study area for improving understanding formation stability similar features. To characterize its provide more reliable information analysis, we used multiple-channel surface-wave technique microtremor array measurements survey dam's S-wave velocity (V-s) profile. Our results show integrated use methods is an effective approach determining irrespective mountainous environment which typically occur. V-s profile suggests displaced materials had little disturbed during movement, movement was rapid over long distance. We also discuss herein landsliding mechanism assess breaching risk due overtopping. (C) 2016 Elsevier B.V. All rights reserved.