Detection of changes in water contents and precaution of failure of slope surface based on elastic wave propagation

2019 Fiscal Year Final Research Report

• Project/Area Number: 16H04407
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Geotechnical engineering
• Research Institution: Saitama University
• Principal Investigator: Uchimura Taro 埼玉大学, 理工学研究科, 准教授 (60292885)
• Project Period (FY): 2016-04-01 – 2019-03-31
• Keywords: 斜面災害 / 早期警報 / 弾性波 / 伝播速度 / 減衰 / 模型実験 / 野外測定 / モニタリング

Outline of Final Research Achievements

In this study, a method to evaluate shear deformation and soil moisture of slopes by using elastic wave is presented. A full-scale multi-layer shear model was used to simulate the pre-failure process of a slope, and the wave propagation was observed. The detailed behavior of elastic wave propagation in soil over a wide range of soil moisture, shear stress, and shear deformation, were explored.
To investigate the behavior of elastic wave propagation in the natural slope surface layer, elastic wave monitoring has been conducted at a slope located at Aso City, Kumamoto, Japan. This slope was suffered from the 2016 Kumamoto Earthquakes and some big cracks appeared on the slope surface. Behaviors of elastic wave velocities and attenuation with soil moisture on-site are similar to laboratory experiments.

Free Research Field

地盤工学

Academic Significance and Societal Importance of the Research Achievements

豪雨による斜面災害の降雨情報や現地計測に基づく早期警報に対して、近年のセンサー、無線、情報の技術の急速な発達にともなって、より低コストかつ高精度で斜面を監視する様々な方法が試されている。本研究は、地盤を伝わる弾性波の伝播特性の変化から、斜面の状態の変化を検知する可能性を探るため、模型と実斜面で斜面表層に雨水が浸透し変形し崩壊する過程を観察して、弾性波速度が変化する要因を検討した。この成果は、斜面の監視と災害の早期警報の簡便な方法を実現するための基礎的な知見となる。