The Effect of Sediment Size and Face Slope on Breach Formation of Non-cohesive Homogeneous Embankments Failed by Overtopping

摘要

Previous research mainly focused on flood propagation and few works were done for dam breach formation. It is difficult because it relates to several branches of knowledge such as hydraulics, sedimentary dynamics and soil mechanics at the same time. Laboratory experi-ments for non-cohesive homogenous embankments failed by overtopping have been undertak-en to research the effects of sediment size and face slope on breach formation in Nanjing Hy-draulic Research Institute (NHRI). According to the results median diameter D50 has little effects on breach formation. Decreasing the downstream face slope has significant effects on it. It can delay the flood peak from dam breach and slow the speed of lateral extension of breach.