Estimating Scour Hole Dimensions of Ski Jump Downstream of Dams Using Granular Computing Model

Document Type : Research Article

Authors

1 M.Sc. Student of Environmental Engineering-Water Resources, Faculty of Environment, University of Tehran, Iran.

2 Assistant professor of Environmental Engineering, Faculty of Environment, University of Tehran, Iran.

3 M.Sc. Student, Surveying and Civil Engineering, College of Engineering, University of Tehran, Iran

Abstract

Accurate estimation of scour parameters such as length, depth and width, have a major role in the management of this quite nonlinear phenomenon. The main goal of this study is to present a method based on granular computing model (GRC) to estimate scour parameters. For this purpose, scour hole of ski jumps downstream of dams (goal functions) were considered to be affected by hydraulic, morphological and geotechnical variables, and GRC model was used for calibration and verification of the phenomena. The implemented linear analysis showed that the goal functions are affected by flow rate variations, waterfall height and deposited particles average size, rather than lip angle. This fact was in compliance with the previous researches. The results also showed the GRC model results in predicting the goal functions had values very close to the measured ones, or with small discrepancies. More investigations showed that the GRC model was superior for estimation of scour depth of ski jumps downstream of dam to the well-known empirical formula proposed by other researchers.

Keywords


سیفی. ا، حسین زاده دلیر. ع، فرسادی زاده. د، (1392)، "آبشستگی در پایین‌دست سرریز لبه پهن دو طرف شیب‌دار"، نشریه دانش آب و خاک، جلد 23، شماره 4، ص.ص. 177-188.
قدسیان. م، اسدی سریزدی. م.ح، (1381)، "ابعاد حفره آبشستگی پایین دست جام‌های پرتابی"، فصلنامه فنی ‌و ‎‌مهندسی مدرس، شماره 8، ص.ص. 107-114.
مومنی وصالیان. ر، موسوی جهرمی. ح، شفاعی بجستان. م، (1387)، "آبشستگی ناشی از جت‌های مستطیلی در پایین دست پرتابه های جامی شکل با مصالح غیریکنواخت"، شماره 2، ص.ص. 203-216.
نوری. ر، کراچیان. ر، خدادادی دربان. ا، شکیبایی نیا. ا، (1386)، "ارزیابی اهمیت ایستگاه‌های پایش کیفی رودخانه‌ها با استفاده از آنالیز مؤلفه‌های اصلی و آنالیز فاکتور، مطالعه موردی رودخانه کارون"، مجله‌ آب و فاضلاب، شماره 63، ص.ص. 60-69.
هوشیاری‌پور. ف، نوری. ر، (1392)، "استفاده از تکنیک ماشین بردار پشتیبان در پیش‌بینی ابعاد چاله‌ آبشستگی پایین‌دست یک پرتابه‌ جامی شکل"، مهندسی آب و محیط زیست ایران، دوره 1، شماره 1، ص.ص. 35-45.
نوری. ر، خاکپور. ا، دهقانی. م، فرخ‌نیا. ا، (1390)، "پیش‌بینی ماهانه جریان با استفاده از ماشین بردار پشتیبان بر مبنای آنالیز مؤلفه‌های اصلی"، یادداشت فنی، مجله آب و فاضلاب، شماره 1، ص.ص. 118-129.
Azmathullah, H.Md, Deo, M.C, and Deolalikar, P.B., )2005(, “Neural networks for estimation of scour downstream of ski-jump bucket”, Journal of Hydraulic Engineering, ASCE, 131(10), pp. 898-908.
Azmathullah, H.Md, Ghani A.A.B, Zakaria, N, Hin, L.S, Kiat, C.C, Siang, L.C. and Hasan, Z.A. (2008), “Genetic programming to predict ski-jump bucket spillway scour”, Journal of Hydrodynamic, 20(4), pp. 477-484.
Bollaert, E.F.R. and Schleiss, A.J. (2003), “Scour of rock due to the impact of plunging high-velocity jets”, PartII: experimental results of dynamic pressures at pool bottoms and in one and two-dimensional closed end rock joints”, Journal of Hydraulic Research, 40(5), pp. 15-30.
Chanson, H. (2004), “The hydraulic of open channel flow”, Elsevior.
Goyal, M. K. (2011), “Estimation of scour downstream of a ski jump bucket using support vector and M5 model tree”, Journal of Water Resour. Manage., 25, pp. 2177-2195.
Hager, W.H. and Minor, H.E. (2004), “Plunge pool scour in prototype and laboratory”, Proceeding of 2004 International Conf. on hydraulics of dam and river structures, April 29-28, Tehran, Iran.
Mason, P.J. and Arumugan, K. (1985), “Free jet scour below dams and flip bucket”, Journal of Hydraulic Engineering, ASCE, 111(2), pp. 220-235.
Martins, RBF. (1975). “Scouring of rocky river beds by free jet spillways.” Journal of Water Power and Dam Construction, 27(4), pp. 152–153.
Momeni Vesalian, R. (2006), “Investigation of scour downstream of dam by physical modle”, Ph.D. thesis, Science and Research Branch, Islamic Azad University, Tehran, Iran, pp. 170.
Rajaratnam, N. and Mazurek, K. (2003), “Erosion of sand by circular impinging water jets with small tailwater”, Journal of Hydraulic Engineering, ASCE, 129(3), pp. 225-229.
Veronese, A. (1937), “Erosion of a bed downstream from an outlet”, Colorado A & M College, Fort Collins, United States.
Wittler, R.J., Annandale, G.W. Abt, S.R. and Ruff, J.F. (1998), “New technology for estimating plunge pool spillway scour”, Proceeding of 1998 Annual Conference of The Association of State Safety Officials, October 11-14, Las Vegas.
Yao, Y.Y. (2004). “A partition model of granular computing, transactions on rough set”, Journal of Subline, 3100, pp. 232-253.
Yao, Y.Y. and Yan, M. (2007), “ICS: An interactive classification system”, Proceedings of the 20th Canadian Conference on Artificial Intelligence (CAI’07), pp. 134-145.
Noori, R, Karbassi, A. R, Moghaddamnia, A, Han, D, Zokaei-Ashtiani, M. H., Forokhnial, A. and Ghafari-Goushesh, M. (2011), “Assessment of input variables determination on the SVM model performance using PCA, Gamma test, and forward selection techniques for monthly stream flow prediction”, Journal of Hydrology, 401, pp. 177-189.
Chandan K. P. S. (2012), “Evaluation of selected equations for predicting scour downstream of ski-jump spillway using laboratory and field data”, Technical Note, Indian Institute of Technology Guwahati, Journal of Engineering Geology, 129, pp. 98-103.