Innovative approach for experimental investigation and monitoring and warning of the evolutionary patterns of dam body failure in earth dams

Dam safety is critical for protecting downstream lives, property, ecosystems, and socio-economic stability. Investigating dam breach mechanisms and establishing safety warning thresholds hold significant scientific and practical value. This study conducted dam breach model tests under diverse conditions and developed a monitoring and warning system using high-precision inclinometers to elucidate deformation characteristics and failure mechanisms. Experimental results revealed three distinct failure stages: tension cracking, localized soil flow/collapse, and catastrophic collapse/landsliding. Precursor phenomena such as seepage and cracking were observed prior to soil flow failure, suggesting that rapid infiltration line reduction during this phase could mitigate large-scale failures. Tilting deformation of the downstream slope was identified as a viable early warning indicator. An improved tangent angle method subdivided the rapid deformation stage into three substages (early, middle, and late) using thresholds of 45°, 80°, and 85°, respectively, to establish tiered warning criteria. Additionally, a reciprocal velocity method was proposed to predict breach timing by characterizing the relationship between the inverse rate of slope angle change and time, demonstrating effective breach time prediction.