Experimental Investigation of Local Half-cone Scouring Against Dam under the Effect of Localized Vibrations in the Sediment Layers

Dodaran, Asgar Ahadpour;Park, Sang Kil;Mardashti, Asadollah;Noshadi, Mehrzad;Afsari, Mohammad

  • Received : 2012.11.05
  • Accepted : 2013.04.26
  • Published : 2013.04.30


Most natural river reach are approximately balanced with respect to sediment inflow and outflow. Dam construction dramatically alters this balance, creating an impounded river reach characterized by extremely low flow velocities and efficient sediment trapping. The impounded reach will accumulate sediment and lose storage capacity until a balance is again achieved, which would normally occur after the impoundment has become "filled up" with sediment and can no longer provide water storage and other benefits. This paper aims to investigate the sediment removal process in dam reservoir using simultaneously pressure flushing operation and vibrator machine. The main objective of this study is to identify the effect of vibrator in flushing cone dimensions. To achieve the objectives of present study, laboratory test have conducted under different hydraulic conditions such as two bottom outlets with diameter equal to 2" and 3", five discharges 0.23, 0.53, 1.21, 1.53 and 2.1 lit/s and only one water depth above the center of bottom outlets. Using the vibrator machine mounted into the reservoir and close to the bottom outlet, different frequency e.g. 20, 35 and 50 HZ, have been introduced to the deposited sediment at the vicinity of outlet. The results indicate that the volume and width of flushing cone are strongly affected by frequency of vibrations. The results indicate that the volume and width of flushing cone are strongly affected by frequency of vibrations.


Pressure Flushing;Local Scouring;Bottom Outlet;Sediment;Localized Vibrator Machine


  1. Kadlec, R.H., Knight, R. L., 1995. Treatment Wetlands. Lewis Publishers, Boca Raton, Fla.
  2. Emamgholizadeh, S., Bina, M., Fathimoghadam, M., Ghomeyshi, M., 2006. Investigation and Evaluation of the Pressure Flushing through Storage Reservoir. ARPN Journal of Engineering and Applied Sciences, 1(4).
  3. Graf, W.H., 1971. Hydraulics of Sediment Transport. McGraw- Hill, New York.
  4. ICOLD, 1988. World Register of Dams, Update. International Commission on Large Dams, Paris.
  5. Julien, P.Y., 1995. Erosion and Sedimentation. Cambridge University Press. Cambridge, U.K.
  6. Meshkati Shahmirzadi, M.E., 2010. Experimental Investigation of Pressure Flushing Operation in Reservoir Storage. MSc thesis, Gorgan University of Agriculture Sciences and Natural R sources, Iran.
  7. Mahmood, K., 1987. Reservoir Sedimentation: Impact, Extent, Mitigation. World Bank Technical Report 71, Washington, D.C.
  8. Scheuerlein, H., Tritthart, M., Nunez Gonzalez, F., 2004. Numerical and Physical Modeling Concerning the Removal of Sediment Deposits from Reservoirs. Conference proceeding of Hydraulic of Dams and River Structures, Tehran, Iran.
  9. Shen, H.W., Lai, J.S., Zhao, D., 1993. Hydraulic Desiltation for Noncohesive Sediment. Proceeding of the 1993 Annual ASCE Hydraulic Engineering Conference, San Francisco, H.W Shen, S.T. Su, and F. Wen, eds, 119-124.
  10. Shen, H.W., Lai, J.S., 1996. Sustain Reservoir useful Life by Flushing Sediment. International Journal of Sediment Research. 11(3), 10-17.
  11. Simons. D.B., Senturk. F., 1992. Sediment Transport Technology. Water Resources Publications, Littleton, Colo.
  12. Vanoni, V.A., 1975. Sedimentation Engineering. ASCE, New York.
  13. White, W.R., Bettess, R., 1984. The Feasibility of Flushing Sediments Through Reservoirs. Challenges in African Hydrology and Water Resources, Proceeding of Harare Symposium, July, D.E. Walling, S.S.D. Foster, P. Wurzel, eds, IAHS Publication.
  14. Brown, C.B., 1943. The Control of Reservoir Silting. United States Department of Agriculture, Miscellaneous Publication No. 521, Washington, D.C., 166.
  15. Chang, H.H., 1988. Fluvial Processes in River Engineering. John Wiley and Sons. New York.
  16. Yang, C.T., 1996. Sediment Transport: Theory and Practice. McGraw-Hill, New York.