Numerical Investigation of Flow through Two Layered Rockfill Dam

Document Type : Research Paper

Authors

Department of Water Structure Engineering, Faculty of Agriculture, Tarbiat Modares University.Tehran,Iran

Abstract

Horizontal layered dams and vertical layered dams are two types of the heterogeneous rock fill dams which can are employed by many engineers for attenuation of peak discharge of flood hydrograph. In this study a two dimensional (2D) computer model has been developed to investigate the flow through two layered rock fill dams. After development of the computer model, its validation has been confirmed using experimental data. Then a series of experiments have been designed to evaluate the flow discharge through two layered rock fill dams. In these experiments, four cases of layered dam have been investigated. The results of this study indicate that in the horizontal two layered dams when the lower layer is made of the finer grained rocks, the flow discharge is less than the other arrangments. Also, in order to demonstrate the model sensitivity to grain size in each layer, a sensitivity analysis has been conducted. Also, the results indicate that in the horizontal tow layered dam for each centimeter change in the rock size of the lower layer, flow discharge changes 9.96 percent, while each centimeter change in the rock size of the top layer leads to only 4.52 percent change in the discharge. In the vertical two layered dam, for each centimeter change in the rock size of the upstream and downstream layers, the flow discharge changes 11.72 and 12.04 percent, respectively.

Keywords


Ferdos, F. and Dargahi, B., (2016a). "A study of turbulent flow in largescale porous media at high Reynolds numbers". Part I:numerical validation. Journal of  Hydraulics Research, 54, pp.663–677.
Ferdos, F. and Dargahi, B. (2016b). "A study of turbulent flow in largescale porous media at high Reynolds numbers". Part II: flow physics. Journal of  Hydraulics Research, 54, pp.678–691.
Forchheimer, P. H. (1901). "Wasserbewegun durch Boden" Zeitschrift dse vereinest Deutscher Ingenieure. 49, pp.1736 – 1749 and 50, pp.1781 – 1788
Hiller, PH., Aberle, J. and Lia, L. (2018)." Displacements as failure origin of placed riprap on steep slopes". Journal of  Hydraulics Research, 56(2).pp. 141– 155.
Houben, G.J., Wachenhausen, J.and Morel, C.R.G. (2018). "Effects of ageing on the hydraulics of water wells and the influence of non-Darcy flow". Hydrogeology Journal. 26(4), pp. 1285–1294 .
Li, Z., Wan, J., Huang, K., Chang, W. and He, Y. (2017). "Effects of particle diameter on flow characteristics in sand columns". International Journal of. Heat Mass Transfer. 104,pp. 533–536 .
Li, Z., Wan, J., Zhan, H., Cheng, X., Chang, W.and Huang, K. (2019). "Particle size distribution on Forchheimer flow and transition of flow regimes in porous media". Journal of Hydrology. 574,pp. 1–11 .
Samani, H. M. V., Samani, J. M. V. and Shayannejad, M.( 2003). "Reservoirrouting using steady and unsteady flow through rockfill dams" Journal of Hydraulic Engineering, 129(6),pp. 448–454.
Samani, J. M. V., Samani, H. M. V. and Shaiannejad, M. (2004). "Reservoir Routing with outflow through rockfill dams" IAHR Journal of Hydraulic Research, 42(4),pp. 435-439.
Samani, J. M. V., Moknatian, M. and Heidari, M. (2013). "Two-dimentional multi-rockfill detention dam flow model in reservoir routing" Engineering and Computational Mechanics166(EM2),pp. 59-67.
Shayannejad, M. and Ashjazadeh, S. ( 2014). "A hydraulic investigation of flow through a two-layered rockfill dam using an experimental model" International Bulletin of Water Resources and Development, 3(6), pp. XVII-XIX.
Stephenson, D. (1979). "Rockfill in Hydraulic Engineering" Elsevier Scientific, Amsterdam.
Wang, L., Li, Y., Zhao, G., Chen, N.and Xu, Y.(2019). "Experimental investigation of flow characteristics in porous media at low Reynolds numbers (Re → 0) under different constant hydraulic heads". Water 11(11), 2317.
Wilkins, J. (1956). "Flow of water through rockfill and its application to the design of dams" Paper presented at the 2nd Australia New Zealand Conference on soil Mechanics And Fundation Engineering, Christchurch, New Zealand.