Overflow-Induced Breaching in Heterogeneous Coarse-Grained Embankment Dams and Levees—A State of the Art Review

This review article synthesizes recent experimental research on the breaching of noncohesive embankment dams and levees caused by overflow, with a specific focus on coarse-grained soil materials. Despite the high incidence of embankment dam collapses leading to significant socio-economic and environmental impacts, comprehensive understanding of the underlying physical processes remains incomplete. Historically, studies have largely concentrated on embankments made from uniform materials ranging from fine cohesive soils to noncohesive clean rockfill. However, recent shifts in focus to well-graded heterogeneous coarse-grained soil materials underscore the complexity of predicting breach mechanics, given the absence of physically based models for these materials. This review aims to compile and elucidate the factors affecting breaching in an effort to inform future research and practical applications in dam safety assessments.