A Dam Break Analysis Using HEC-RAS
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Abstract
This paper firstly described the dam break in the aspects of theories and models. Break parameters prediction, the understanding of dam break mechanics, peak outflow prediction were shown as the essential for the dam break analysis, and eventually determined the loss of the damages. Secondly, as an application example, Foster Joseph Sayers Dam break was further modeled and analyzed using USACE Hydrologic Engineering Center’s River Analysis System (HEC-RAS) model based on available geometry data. The results show that dam break is a complicated and comprehensive process involving lots of principles. Combination of mechanics and case studies, reflection of predominant mechanisms of headcut erosion, more specific categorization of dam, prudent investigation and inference of dam break process are needed in developing a satisfactory dam break simulation model. Foster Joseph Sayers Dam break due to piping elongates the time period of high water surface level, which increases the duration of risk. However, the dam break does not increase the downstream maximum water surface elevation (Max. W.S. Elev) significantly at previous design Probable Maximum Flood (PMF). Dam break has a greater impact on the downstream location where is closer to the dam in accordance with the comparison of the hydrographs at different downstream locations. Sensitivity analysis demonstrates that the changes of dam break parameters had no much influence on the downstream Max. W.S. Elev.
- [1] Dam Safety Office, “Prediction of Embankment Dam Breach Parameters–A Literature Review and Needs Assessment,” Water Resources Research Laboratory, Denver, July 1998.
- T. Dincergok, “The Role of Dam Safety in Dam-Break Induced Flood Management,” International Conference on River Basin Management, Kos, 23-25 May 2007, pp. 683-691.
- R. A. Dodge, “Overtopping Flow on Low Embankment Dams – Summary Report of Model Tests,” U.S. Bureau of Reclamation, Denver, August 1988, pp. 27-28.
- D. M. Gee and G. W. Brunner, “Dam Break Flood Routing using HEC-RAS and NWS-FLDWAV,” Proceeding of Environmental Engineering; Water Resources Management, World Water Congress, 2005.
- US Army Corps of Engineers, “HEC-RAS River Analysis System, User’s Manual Version 4.0 Beta,” Hydrologic Engineering Center, November 2006.
- US Army Corps of Engineers, “HEC-RAS River Analysis System, Applications Guide Version 3.1,” Hydrologic Engineering Center, November 2002.
- G. R. Powledge, D. C. Ralston, P. Miller, Y. H. Chen, P. E. Clopper and T D. M. emple, “Mechanics of Overflow Erosion on Embankments. II: Hydraulic and Design Considerations,” Journal of Hydraulic Engineering, Vol. 115, No. 8, 1989, pp. 1056-1075. doi:10.1061/(ASCE)0733-9429(1989)115:8(1056)
- V. P. Singh and P. D. Scarlatos, “Analysis of Gradual Earth-Dam Failure,” Journal of Hydraulic Engineering, Vol. 114, No. 1, 1988, pp. 21-42. doi:10.1061/(ASCE)0733-9429(1988)114:1(21)
- D. M. Temple and G. J. Hanson, “Headcut Development in Vegetated Earth Spillways,” American Society of Agricultural and Biological Engineers, Vol. 10, No. 5, 1994, pp. 677-682.
- U.S. Army Corps of Engineers, “Engineering and Design –Hydrologic Engineering Requirements for Reservoirs,” EM 1110-2-1420, 31 October 1997.
- U.S. Bureau of Reclamation, “Downstream Hazard Classification Guidelines,” ACERTechnical Memorandum NO. 11,Assistant Commissioner-Engineering and Research, Denver, December 1988.
- Dam Safety Office, “Predicting Embankment Dam Breach Parameters –A Literature Review and Needs Assessment,” Water Resources Research Laboratory, San Francisco, August 1997.
- T. L. Wahl, “Uncertainty of Predictions of Embankment Dam Breach Parameters,” Journal of Hydraulic Engineering, Vol. 130, No. 389, 2004, pp. 389-397. doi:10.1061/(ASCE)0733-9429(2004)130:5(389)