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

Abstract

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.

Review of Historical Dam-Break Events and Laboratory Tests on Real Topography for the Validation of Numerical Models

“…Data on the propagation of the dam-break flood wave downstream are also available in most of these cases. Some events listed in Table 1 have already been inserted in other databases, especially concerning the peak outflow resulting from an earthen dam failure [41][42][43][44][45][46]. The same applies to some dam-break cases presented in the next section.…”

Potential Dam Breach Flood Assessment with the 2D Diffusion and Full Dynamic Wave Equations Using a Hydrologic Engineering Center-River Analysis System

“…The downstream peak of the homogeneous dam was found to be higher than the zonal rockfill dam, as the breach duration was short for a homogeneous dam due to quick erosion. Ashraf [13] studied the large-scale physical model to establish the relationship between breach parameters, considering the breach opening, outflow peak, and breaching time through statistical methods using a regression model. The non-linear regression model resulted in a good arrangement with the physical model test.…”

Impact of Dam Materials and Hydraulic Properties on Developing the Breaching Dimensions

“…The results showed that the use of the mesh adaptation method to simulate these problems has considerably increased the accuracy and significance of simulation time-saving. Also, Ashraf et al [9] assessed embankment dam breach parameters using laboratory modeling to provide a vision of the failure of embankments due to overtopping failure. Both cohesive and non-cohesive embankments were tested.…”