Experimental and numerical evaluation of the effects of dam reservoir sediments on sediment transfer mechanism due to dam failure

Document Type : Research Article

Authors

1 Department of Civil engineering,, Science and Research Branch, Islamic Azad University Tehran, Iran

2 Department of civil engineering, science and research branch, Islamic azad university, Tehran, Iran

3 Zazd University, Babol Branch

4 Science and Research Branch, Islamic azad University

Abstract

Introduction
Dams are considered one of the most important infrastructure facilities of a country, which play a very important role in economic prosperity through storage, regulation of water, and also energy production. Due to the volume of water stored in the reservoir of these dams and sometimes their proximity to residential areas, the failure of dams can lead to a lot of human and financial losses, which can be prevented by having sufficient information and proper forecasts of dam failure. The flow resulting from the dam failure is turbulent, mainly a mixture of fluid and sediment particles. Therefore, after the dam's failure, sediment transport leads to significant morphological changes downstream. Based on this, the analysis and evaluation of the instantaneous failure of the dam have been one of the main challenges of the profession of engineers and activists in this field. By examining the research background, it is clear that the studies focused on fluid flow in non-erodible bed conditions, and a small part of numerical and laboratory research has been focused on the evaluation of changes in the morphology of the bed sediment layer. In addition, one of the effective parameters in the mechanism of sediment transfer and the pattern of morphological changes of the bed is the sediments of the dam reservoir, which has received less attention from researchers. Therefore, in this research, we have evaluated and experimental-numerically modeled the phenomenon of sediment transport due to the sudden failure of the dam, taking into account the sediment layer in the dam reservoir.

Methodology
In this study, two variables (1- the type of sediment particles (fine sand and coarse sand) and 2- the thickness of the sediment layer in the reservoir and downstream of the dam) have been investigated as the main parameters in the evaluation of the sediment transport mechanism (changes in bed morphology). Based on this, scenarios have been defined for laboratory and numerical modeling. In this research, to evaluate the phenomenon of bed sediment transfer based on the phenomenon of instantaneous dam failure, four tests have been defined and implemented in the hydraulic laboratory flume of Babol University in different conditions. This flume is 10 meters long, 50 cm wide, and 50 cm high and is equipped with an ultrasonic level gauge and a digital pressure gauge. In these experiments, two parameters of the type of bed sediment materials (A, B) and also the thickness of the sediment layer downstream of the dam and the reservoir of the dam have been considered as modeling variables. Type A materials are gravel particles with an average diameter of 20 mm, and type B materials are sand particles with an average diameter of 3 mm.

Results and Discussion
According to the research variables, four scenarios for laboratory modeling and six scenarios for numerical modeling of the phenomenon of sediment transfer based on instantaneous dam failure have been defined. The results of the numerical modeling showed that the numerical model of the research had acceptable accuracy in simulating the phenomenon of sediment transfer due to dam failure, so the modeling error for two-dimensional numerical models (the first four models based on Table 2) is respectively equal to 2.75%, 4.31%, 2.59%, 5.52% compared to laboratory tests.
The results showed that in the models of type B sediment materials, the amount of reduction in the thickness of the sediment layer is greater than in the models with type A sediment materials; in other words, the amount of reduction in the thickness of the sediment layer in type B materials is more than type B. The material was A. Therefore, the decrease in the diameter of the sediment particles has caused an increase in the thickness of the sediment layer (bed morphology) due to the failure of the instantaneous dam. In addition, by examining the results obtained from laboratory and numerical models, it was determined that the reservoir sediment layer of the dam is an effective parameter in the rate of sediment transfer and the occurrence of changes in the morphology of the bed based on the dam failure currents, in such a way that with the increase in the thickness of the sediment layer of the reservoir Compared to the downstream sediment layer of the dam, the changes in the thickness of the bed layer have increased by about 10%, as well as the rate of sediment transfer in these conditions.
By evaluating the results of dam failure modeling in three-dimensional space, it is clear that the thickness of the sediment layer in the 3D_DB1_NB1 model with type B materials has decreased more compared to the 3D_DB1_NA1 model with type A materials. In addition, according to the contour of the changes in the thickness of the bed layer, it is clear that the type of material of the sediment particles (diameter of the sediment particles) was an effective factor in evaluating the phenomenon of sediment transport in the 3D modeling space. In both 3D models, the thickness of the sediment layer in the area of the dam valve (failure area) has decreased and increased in the range of 1.8 to 2 meters and decreased from 2.2 to 3 meters.

Conclusion
In this research, the main goal is to evaluate the mechanism of sediment transfer due to the sudden failure of the dam, focusing on the effect of the sediment layer in the dam reservoir, which has been implemented in the form of laboratory and numerical modeling. Also, the effect of three parameters, the type of sediment particles and the thickness of the sediment layer in the reservoir and downstream of the dam axis, has been studied.
Based on the results of this research and the evaluation and comparisons made between the numerical models and the laboratory model, it is clear that the numerical model created in both two-dimensional and three-dimensional spaces has an acceptable accuracy in simulating the phenomenon of sediment transfer due to dam failure.

Keywords

Main Subjects

References

Ai, C., Ma, Y., Ding, W., Xie, Z. & Dong, G. (2022). Three-dimensional non-hydrostatic model for dam-break flows. Physics of Fluids, 34(2), 022105, https://doi.org/10.1063/5.0081094.
Cao, Z., Pender, G., Wallis, S. & Carling, P. (2014). Computational Dam-Break Hydraulics over Erodible Sediment Bed. J. Hydraul. Eng., 130, 689-703.
Capart H. & Young D.L.  (1998).  Formation of a jump by the dam-break wave over a granular bed.  J. Fluid. Mech, 372, 165–187.
Fraccarollo, L. & Capart, H. (2002). Riemann wave description of erosional dam-break flows. Journal of Fluid Mechanics, 461, 183–228.
Garoosi, F., Mellado-Cusicahua, A.N., Shademani, M. & Shakibaeinia, A. (2022). Experimental and numerical investigations of dam break flow over dry and wet beds. International Journal of Mechanical Sciences, 215, 106946, https://doi. org/10.1016/j.ijmecsci.2021.106946.
Graham, W.J. (1999). A Procedure for Estimating Loss of Life Caused by Dam Failure. U.S. Department of Interior Bureau of Reclamation Dam Safety Office Denver, Colorado, USA.
Greimann, B., Lai, Y. & Huang, J. (2008). Two-dimensional total sediment load model equations. Journal of Hydraulic Engineering, 134(8), 1142-1146.
Goutiere L., Soares-Frazão S. & Zec, Y. (2011). Dam-break flow on mobile bed in abruptly widening channel: Experimental data. J. Hydraul. Res., 49(3), 367–371.
International Commission on Large Dams (1995). Dam failures statistical analysis. Bulletin 99, Paris, France.
Issakhov, A. & Zhandaulet, Y. (2020). Numerical Study of Dam Break Waves on Movable Beds for Complex Terrain by Volume of Fluid Method. Water Resources Management, 34(2), 463-480.
Khoshkonesh, A., Daliri, M., Riaz, K., Dehrashid, F.A., Bahmanpouri, F. & Di Francesco, S. (2022). Dam-break flow dynamics over a stepped channel with vegetation. Journal of Hydrology, 613, 128395, https://doi.org/10.1016/j.jhydrol.2022. 128395.
Khosravi, K., Habibnejad, M., Shahedi, K., Chegini, A. & Tiefenbacher, J.P. (2020). Experimental investigation of bed evolution resulting from dam break. Journal of Hydraulic Structures, 6(2), 23-33.
Kocaman, S., Evangelista, S., Guzel, H., Dal, K., Yilmaz, A. & Viccione, G. (2021). Experimental and numerical investigation of 3d dam-break wave propagation in an enclosed domain with dry and wet bottom. Applied Sciences, 11(12), 5638, https://doi.org/10.3390/app11125638.
Liu, Y., Yang, C. & Chen, X. (2022). Experimental study of bed morphology evolution under two-dimensional dam-break flow. Journal of Hydraulic Research, 60(3), 496-503.
McMullin, N. (2015). Numerical and experimental modeling of dam break interaction with a sediment bed, PhD thesis, University of Nottingham.
Pritchard, D. & Hogg, A. (2002). On sediment transport under dam break flow. J. Fluid Mech., 473, 265-274.
Qian H., Cao Zh., Liu H. & Pender G. (2017). New experimental dataset for partial dam break floods over mobile beds. J. Hydraul Res., 56(1), https://doi.org/10.1080/00221686.2017.1289264.
Razavitoosi, S.L., Ayyoubzadeh, S.A. & Valizadeh, A. (2014). Two-phase SPH modelling of waves caused by dam break over a movable bed. International Journal of Sediment Research, 29(3), 344–356.
Rodi, W. (2017). Turbulence modeling and simulation in hydraulics: A historical review. Journal of Hydraulic Engineering, 143(5), 03117001, https://doi.org/10.1061/(ASCE)HY. 1943- 7900.0001288
Selim, T., Hesham, M. & Elkiki, M. (2022). Effect of sediment transport on flow characteristics in non-prismatic compound channels. Ain Shams Engineering Journal, 13(6), 101771, https://doi.org/10.1016/j.asej.2022.101771.
Soares-Frazão S., Canelas R., Cao Z., Cea L., Chaudhry H.M., Moran A.D. & Zech, Y. (2012). Dam-break flows over mobile beds: Experiments and benchmark tests for numerical models. J. Hydraul. Res., 50(4), 364–375.
Stoker, J.J. (1957). Water waves, Wiley-Interscience, New York.
Wang, B., Liu, W., Wang, W., Zhang, J., Chen, Y., Peng, Y., Liu, X. & Yang, S. (2020). Experimental and numerical investigations of similarity for dam-break flows on wet bed. Journal of Hydrology, 583, 124598, https://doi.org/10.1016/j.jhydrol.2020. 124598.
Wang, B., Zhang, J., Chen, Y., Peng, Y., Liu, X. & Liu, W. (2019). Comparison of measured dam-break flood waves in triangular and rectangular channels. Journal of Hydrology, 575, 690-703.
Wu, G., Yang, Z., Zhang, K., Dong, P. & Lin, Y.-T. (2018). A Non-Equilibrium Sediment Transport Model for Dam Break Flow Over Moveable Bed Based on Non-Uniform Rectangular Mesh. Water, 10(5), 616, https://doi.org/10.3390/w10050616.
Wu, W. (2007). Computational river dynamics. Crc Press.
Wu, W. & Wang, S.S. (2007). One-dimensional modeling of dam-break flow over movable beds. Journal of Hydraulic Engineering, 133(1), 48-58.
Wu, W. (2004). Depth-averaged two-dimensional numerical modeling of unsteady flow and nonuniform sediment transport in open channels. Journal of Hydraulic Engineering, 130(10), 1013-1024.
Zhang, Y., Li, Z., Wang, J., Ge, W. & Chen, X. (2022). Environmental impact assessment of dam-break floods considering multiple influencing factors. Science of The Total Environment, 837, 155853, https://doi.org/10.1016/j.scitotenv.2022. 155853.

Files

History

  • Receive Date: 18 February 2023
  • Revise Date: 15 July 2023
  • Accept Date: 17 July 2023

Share

How to cite

Statistics