Assessment of embankment dams breaching using large scale physical modeling and statistical methods

Understanding the failure mechanisms of embankment dams due to overtopping is essential for the design of flood mitigation, flood mapping, and flood warning systems. The breach process in embankment dams can be characterized using breach parameters such as breach opening dimensions, time of breach formation, and peak breach outflow. The main objective of this study is to derive new set of statistical equations to predict the target breach parameters. A database of 126 events of embankment failure was collected and then multiple nonlinear regression analysis is used to derive the new set of equations and the uncertainty in the computed parameters was quantified. Finally, five large-scale overtopping failure tests were conducted on cohesive and non-cohesive soils embankments. The derived breach parameters equations showed good agreement with the results of the physical models for non-cohesive soil embankments, while the failure of cohesive soil embankments varied significantly with soil properties; indicating that breach parameters in cohesive soil embankment should be computed based on not only embankment dimensions but soil properties as well.