A slope management method by monitoring soil volumetric water content and its validation through numerical analysis

• Published in: IOP conference series. Earth and environmental science Vol. 1334; no. 1; pp. 12030 - 12037
• Main Authors: Yoshida, S, Xiong, X, Muramatsu, R, Fukada, S, Matsumoto, T
• Format: Journal Article
• Language: English
• Published: Bristol IOP Publishing 01.05.2024
• Subjects: Admixtures; Boreholes; Environmental monitoring; Finite element method; Gauges; Groundwater; Groundwater levels; Impact analysis; Landslides; Mathematical analysis; Moisture content; Moisture meters; Monitoring; Monitoring methods; Numerical analysis; Qualitative analysis; Rainfall; Safety; Safety factors; Safety management; Soil analysis; Soil investigations; Soil moisture; Soil water; Three dimensional analysis; Three dimensional models; Topsoil; Water content; Water levels
• ISSN: 1755-1307; 1755-1315
• DOI: 10.1088/1755-1315/1334/1/012030

Abstract Landslides induced by heavy rainfall have become increasingly common in recent years. As the groundwater level rises, the safety factor of slopes tends to decrease. However, traditional monitoring methods, such as employing water-level (pressure) gauges in boreholes, require significant effort. Thus, this study proposes a slope management approach based on monitoring the volumetric water content of the ground surface. The monitored slope, approximately 20 m in height and 30 m in length, consists of topsoil mixed with grass roots and sand with a slight silt admixture, as revealed by two borehole investigations. Soil moisture meters were strategically installed at three locations along the slope (upper, middle, and lower sections) to gauge the volumetric water content. Observations indicated a sensitive increase in ground water content following rainfall. Furthermore, a three-dimensional Finite Element Method (FEM) analysis was employed to explore the correlation between rainfall (intensity and duration) and groundwater content. The FEM analysis also examined the impact of rainfall-induced changes in slope water content on the overall slope safety factor, utilizing 3D point cloud data to model the monitored slope. Qualitative agreement was observed between the monitoring and analysis results, highlighting a decrease in slope safety factor as slope water content increased. These findings underscore the potential of conveniently assessing slope safety factors based on the water content of a slope’s ground surface.