DEVELOPMENT OF SAFE, EFFICIENT ENGINEERING MEASURES FOR DESIGN, ANALYSIS, AND REHABILITATION OF HYDRAULIC STRUCTURES AND CHANNELS
Location: Hydraulic Engineering Research
Title: Discussion of internal erosion modeling
Submitted to: State Dam Safety Officials Association Proceedings
Publication Type: Proceedings
Publication Acceptance Date: September 4, 2012
Publication Date: September 19, 2012
Citation: Tejral, R.D., Hanson, G.J., Temple, D.M. 2012. Discussion of internal erosion modeling. In: Dam Safety 2012. Proceedings of the Association of State Dam Safety Officials Annual Conference, September 16-20, 2012, Denver, CO. CDROM.
Internal erosion is one common mode of dam failure. Internal erosion occurs when water flows through a cavity, crack, and/or other continuous opening within the embankment, detaching material. The detachment of material (erosion) results in expansion of the continuous flow path, increased discharge, and eventual dam failure and breach. This paper discusses two process-based models, including the computational breach tools and their underlying principles. Models considered are the National Weather Service BREACH and the simplified breach analysis model for internal erosion, IESIMBA being developed by the USDA-ARS. Underlying assumptions and equations used to describe the erosion process are significantly different. NWS BREACH is a sediment transport driven model whereas IESIMBA is primarily a detachment and headcut migration model. Comparisons of model predictions are made based on predictions of physical model test results, case studies, and simulated dams. Sensitivities to material properties, dam height, reservoir storage, and pipe elevation are explored.