An experimental examination of riprap effects on homogeneous embankment dams overtopping breach

نوع مقاله : مقاله کامل (پژوهشی)

نویسندگان

1 دانشجوی دکتری مهندسی عمران (آب و سازه‌های هیدرولیکی)، دانشکده فنی و مهندسی، دانشگاه ارومیه

2 استاد مهندسی عمران-هیدرولیک و مکانیک مهندسی رودخانه، دانشکده فنی و مهندسی دانشگاه ارومیه

3 عضو هیات علمی پژوهشکده هیدرولیک، موسسه تحقیقات آب

4 شرکت مدیریت منابع آب ایران

چکیده

The overtopping phenomenon is the most common cause of embankment dams’ failure, and it includes a complicate process. In present research, a physical model of an earth dam covered by riprap was constructed, and its hydraulic outcomes were compared with a benchmark model by providing a three-scenario framework. The main results indicated that the breach process of physical models follows three stages including: initiation, development, and termination. Furthermore, the use of riprap has no significant effects on the peak flow discharge caused by the breach procedure. In the first scenario, without a filter layer, the breach process had the highest resemblance to the benchmark model. For the second scenario, by employing a composite system, the occurrence of 129% increase in the breach time and the longest duration of the end stage were recorded. For the third scenario, by employing a composite system at the downstream slope, 86% increase in breach time and no change in the terminal stage duration was observed. Besides, the mass of eroded material was calculated according to the achieved sedimentation pattern. In the second scenario, the maximum thickness of sediment was measured; it proved the transport influence of riprap at the downstream of laboratory channel. A relatively symmetrical sedimentation pattern was then observed. Moreover, more than 50% of riprap material was transported to the downstream. This paper comprises the simultaneous measurements of breach geometry, flow hydrograph, and ultimate sedimentation patterns may help researchers in this field of study, indeed.

کلیدواژه‌ها

موضوعات


Abdellatif Mohamed, M.M. & El-Ghorab, E.A.S. (2016). Investigating scale effects on breach evolution of overtopped sand embankments. Water Sci, 30, 84-95.
Ahadiyan, J., Bahmanpouri, F., Adeli, A., Gualtieri, C. & Khoshkonesh, A. (2022). Riprap effect on hydraulic fracturing process of cohesive and non‑cohesive protective levees. Water Resour Manag, 36, 625-639.
Alhasan, Z., Jandora, J. & Ríha, J. (2015). Study of dam-break due to overtopping of four small dams in the Czech Republic. Acta Universitatis Agriculturae et Silviculturae Mendelianae Brunensis, 63, 717-729.
Al-Riffai, M. (2014). Experimental study of breach mechanics in overtopped non-cohesive earthen embankments. PhD thesis, University of Ottawa, Ottawa, Canada.
Association of state dam safety officials (2023). Kentucky, USA. https://damsafety.org.
ASTM D422-63 (2002). Standard test method for particle size analysis of soils.
ASTM D1557 (2007). Standard test methods for laboratory compaction characteristics of soil using standard effort. West Conshohocken, PA, USA.
ASTM D3080 (2003). Standard test method for direct shear test of soils under consolidated drained conditions. Annual Book of ASTM Standards, Philadelphia 408, 1-7.
Brunner, G.W. (2016). HEC-RAS Reference Manual, version 5.0. Hydrologic Engineering Center, Institute for Water Resources, US Army Corps of Engineers, Davis, California.
Coleman, S.E., Andrews, D.P. & Webby, M.G. (2002). Overtopping breaching of non-cohesive homogeneous embankments. J. Hydraul. Eng., 128, 829-838.
Committee on dam safety (2019). ICOLD incident database bulletin 99 update: statistical analysis of dam failures. Technical report, international commission on large dams. https://www.icoldchile.cl/boletines/188.pdf
EL-Ghorab, E.A., Fahmy, A. & Fodda, M. (2013). Large scale physical model to investigate the mechanics of embankment erosion during overtopping flow. Eng. Res. J., 36, 287-302.
Engomoen, B., Witter, D.T., Knight, K. & Luebke, T.A. (2014). Design Standards No 13: Embankment Dams, USBR.
Froehlich, D.C. (2016). Predicting peak discharge from gradually breached embankment dam. J. Hydrol. Eng., 21, 04016041, http://dx.doi.org/ 10.1061/(ASCE)HE.1943-5584.0001424.
Hakimzadeh, H., Nourani, V. & Amini, A.B. (2014). Genetic programming simulation of dam breach hydrograph and peak outflow discharge. J Hydrol Eng, 19, 757-768.
Kouzehgar, K., Hassanzadeh, Y., Eslamian, S., Yousefzadeh Fard, M. & Babaeian Amini, A. (2021). Physical modeling into outflow hydrographs and breach characteristics of homogeneous earthfill dams failure due to overtopping. Journal of Mountain Science, 18, 462-481.
Morris, M. & Hassan, M. (2005). IMPACT: Investigation of extreme flood processes and uncertainty-a European research project. In: Defra Flood and Coastal Management Conference 2005, 5-7 July 2005, York, UK.
Msadala, V.P. (2016). Sediment transport dynamics in dam-break modelling. PhD thesis, Stellenbosch University, Stellenbosch, South Africa.
Novak, P., Moffat, A.I.B., Nalluri, C. & Narayanan, R. (2017). Hydraulic Structures. CRC Press.
Pickert, G., Weitbrecht, V. & Bieberstein, A. (2011). Breaching of overtopped river embankments controlled by apparent cohesion. J. Hydraul. Res., 49, 143-156.
Saberi, O. (2016). Embankment dam failure outflow hydrograph development. PhD Thesis, Graz University of Technology, Austria.
Sadeghi, E. & Ahadiyan, J. (2018). Hydraulically failure mechanism of non-cohesive homogeneous protective embankments by overtopping. Journal of Irrigation Sciences and Engineering, 41, 115-131.
USACE (2004). General design and construction considerations for Earth and rockfill dams. US Army Corps of Engineers, Washington DC, USA.
USBR (1987). Design of small dams. Bureau of Reclamation, Water Resources Technical Publication.