Method for monitoring the structure health of a slope focusing on qasi-saturated phenomenon

2021 Fiscal Year Final Research Report

• Project/Area Number: 19K04599
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 22030:Geotechnical engineering-related
• Research Institution: Osaka University
• Principal Investigator: Koizumi Keigo 大阪大学, 工学研究科, 助教 (10362667)
• Co-Investigator(Kenkyū-buntansha): 小松 満 岡山大学, 環境生命科学研究科, 准教授 (50325081)
• Project Period (FY): 2019-04-01 – 2022-03-31
• Keywords: 斜面崩壊 / 集中豪雨 / 健全度診断 / 体積含水率 / 現地計測 / 土中水分 / 予防保全

Outline of Final Research Achievements

Due to the recent extreme weather conditions, damage caused by slope failures has occurred frequently, and countermeasures are urgently needed. In contrast, the current warning criteria based on rainfall are based on the concept of "breakdown maintenance", which can prevent human damages but not prevent slope failures itself. Therefore, this study proposes a method for estimating the existence and depth of the slip surface, which is a factor in slope failure, in order to determine if there is a risk of slope failures. As a result, we proposed a method to estimate the slip surface depth, which is the main cause of rain-induced slope failure, by measuring the change of volumetric water content in the depth direction, and showed its usefulness on a real slope.

Free Research Field

地盤工学

Academic Significance and Societal Importance of the Research Achievements

現行の斜面災害に対する警戒基準は事後保全の考え方に基づくため，豪雨時の人的被害は防げるが，崩壊そのものを防ぐことはできない。これに対し本研究の成果を活用すれば，降雨時の斜面の健全性を診断できる可能性が示された。この成果は予防保全の考え方に基づくものであり，今後，本手法を改良していくことによって，豪雨時の人的被害を防ぐだけでなく，予め崩壊の危険性がある斜面を検出でき，その斜面に対策を施すことで，斜面災害そのものの減少に寄与できる可能性がある。