Project 1.5: Internal Erosion in Earth Dams – Strategies for Remediation and Assessment of Existing Infrastructure

The resilience of embankment dams and flood levees is increasingly critical in the context of climate change, with internal erosion recognized as a leading cause of dam failures worldwide. In India, where over 5,000 large dams exist, internal erosion accounts for the majority of failures, posing risks to communities, hydroelectric capacity, and infrastructure. Catastrophic incidents such as the Gouhou Dam collapse in China and sinkhole formation at the WAC Bennett Dam in Canada highlight the severe consequences of suffusion and piping. Current design practices often rely on empirical particle size distribution criteria, which inadequately capture the complex micro-mechanical processes driving erosion. Recent international research emphasizes the role of stress transmission, hydraulic gradients, and seepage velocities in fines migration, underscoring the need for science-based approaches. This proposal aims to advance understanding of suffusion mechanisms through laboratory reconstitution of soils, advanced imaging, and stress-path testing, complemented by field studies on selected Indian dams. By linking particle grading, soil fabric, and micro-mechanical behaviour, the study will develop a rational framework for assessing erosion susceptibility. Simulations combining discrete element and fluid dynamics methods will further elucidate the physics of fines migration under varied stress and hydraulic conditions. Core samples from existing dams will provide insights into long-term fines migration and material instability. The expected outcomes include guidelines for evaluating dam susceptibility to internal erosion, improved risk assessment methodologies, and strategies for preventive and remedial measures. This research will contribute to safer, more resilient dam infrastructure and sustainable water resource management.