Numerical and Field Investigations of Local Bridge Abutment Scour and Unsteady Downstream River Flow From a Nearby Hydropower Plant

Arvydas Šikšnys; Narimantas Titas Ždankus; Gintautas Sabas; Oksana Barvidienė

doi:10.3846/bjrbe.2014.27

Numerical and Field Investigations of Local Bridge Abutment Scour and Unsteady Downstream River Flow From a Nearby Hydropower Plant

Authors

Arvydas Šikšnys Institute of Hydraulic Engineering, Aleksandras Stulginskis University, Universiteto g. 10, 53361 Akademija, Kaunas, Lithuania
Narimantas Titas Ždankus Dept of Civil Engineering and Architecture, Kaunas University of Tehnology, Studentų g. 48, 51367 Kaunas, Lithuania
Gintautas Sabas Dept of Hydraulics, Vilnius Gediminas Technical University, Saulėtekio al. 11, 10223 Vilnius, Lithuania
Oksana Barvidienė Dept of Hydraulics, Vilnius Gediminas Technical University, Saulėtekio al. 11, 10223 Vilnius, Lithuania

DOI:

https://doi.org/10.3846/bjrbe.2014.27

Keywords:

hydrodynamic model, Kaunas hydropower plant, hydropower plants (HPP), bridge abutment scour

Abstract

Sudden and often fluctuations of water discharges and levels in the downstream reach of the hydropower plant make water fauna and flora existence conditions unbearable. Besides, a riverbed here is subjected to long lasting and intensive scour and deformations. The aim of our investigations is to develop measures improving the water flow regime in the downstream reach of the hydropower plants. The Nemunas River and Kaunas hydropower plants were selected as basis for our numerical and field investigations. Actual flow regime below the hydropower plant was observed and analysed on the ground of the long lasting dynamic measurement data. Numerical treatment of field measurement data and flow simulation works were arranged and carried out simultaneously. Numerical hydrodynamic model MIKE 21 made it possible to evaluate existing river flow conditions and to apply the model for simulation of many different turbine regimes and to select the optimal one. The content of our research was as follows: 1) analysis of typical turbines regimes while switching them on and off and flow regimes downstream; 2) continuous long lasting measurement of water level in many cross-sections of the river under investigation downstream the hydropower plants; 3) numerical simulation and investigation of untypical turbines regimes while switching them on and off and flow regimes downstream with application software MIKE 21 in the same unsteady flow conditions in which field measurements were made; 4) evaluation of the accuracy of hydrodynamic modeling results and possibilities for their application in predicting the local bridge abutment scour. The obtained data on water level and flow rate dynamics downstream the Kaunas hydropower plants have been analysed. Numerical model was developed to simulate the scour at bridge abutment and was calibrated for the same unsteady flow conditions. The obtained accurate results can be used for local bridge abutment scour evaluation.

References

Gjunsburgs, B.; Govsha, J.; Lauva, O. 2014. Scour at Layered River Bed: Reason of the Structures Failure, in Proc. of the 9th International Conference “Environmental Engineering”: selected papers. May 22–23, 2014, Vilnius, Lithuania. Vilnius: Technika: 1–6. http://dx.doi.org/10.3846/enviro.2014.076

Kamaitis, Z. 2012. Influence of Functionality Obsolete Bridges on the Efficiency of Road Network. Part I: Obsolescence Characteristics and Assessment, The Baltic Journal of Road and Bridge Engineering 7(3):173‒180. http://dx.doi.org/10.3846/bjrbe.2012.24

Esmaeili, T.; Dehghani, A.; Pirestani M. R.; Sumi, T. 2011. Numerical Simulation of Skewed Slot Effect on Local Scour Reduction, Journal of Water Siences Research 3(1): 69–80.

Kaganov, G. M.; Volkov, V. I.; Sekisova, I. A. 2010. Sravnenie Parametrov Volny Proryva, Opredelennyh Razlichnymi Metodami, Gidrotehnicheskoe Stroitelstvo 1: 31–37.

Labutina, T. M. 1985. Formation and Forecasting of Hydrochemical Regime of Water Reservoirs in the USSR North-East. Yakut Dept of Siberian Branch of the USSR Academy of Science. 79 p.

Milius, P.; Darbutas, A. 2011. Nemuno vagos dugno ties Kaunu pokyčių dinamika, jų priežastys ir tendencijos [Dynamics, Reasons and Tendencies of the Changes in the Nemunas Riverbed Bottom at Kaunas], Water Management Engineering 38(58): 42–54.

Moncada-M. A. T.; Aguirre-Pe, J. C.; Bolivar, J. C.; Flores, E. J. 2009. Scour Protection of Circular Bridge Piers with Collars and Slots, Journal of Hydraulic Resourses 47(1): 119–126. http://dx.doi.org/10.3826/jhr.2009.3244

Richardson, J.; Davis, S. 2001. Evaluating Scour at Bridges. 4th edition. Federal Highway Administration Hydraulic Engineering Circular No. 18, FHWA NHI 01-001. 378 p.

Salaheldin, T. M.; Imran, J.; Chaudhry, M. H. 2004. Numerical Modeling of Three-Dimensional Flow Field around Circular Piers, Journal of Hydraulic Engineering 130(2): 91–100. http://dx.doi.org/10.1061/(ASCE)0733-9429(2004)130:2(91)

Skibniewski, M.; Tserng, H.; Ju, Sh.; Feng, Ch.; Lin, Ch.; Han, J.; Weng, K.; Hsu, Sh. 2014. Web-Based Real Time Bridge Scour Monitoring System for Disaster Management, The Baltic Journal of Road and Bridge Engineering 9(1): 17–25. http://dx.doi.org/10.3846/bjrbe.2014.03

Šikšnys, A.; Sabas, G. 2011. Nenusistovėjusio vandens tekėjimo Kauno HE žemutiniame bjefe natūriniai ir modeliniai tyrimai [Field and Model Investigations of Unsteady River Flow Downstream of Kaunas Hydropower Plant (HPP)], Water Management Engineering 39(59): 14–22.

Vaikasas, S.; Poškus, V. 2009. HE turbinų įjungimo sukeliamos potvynio bangos žemutiniame bjefe tyrimai [The Investigation of HPP Turbines Switch Impact in Riwer Lower Reaches], Water Management Engineering 35(55): 103–109.

Voskobojnik, A. A.; Voskobojnik, A. V.; Voskobojnik, V. A.; Marchenko, A. G.; Nikishov, V. I. 2006. Lokanyj Razmyv Grunta pri Vzaimodejstvii Mostovyh Opor, Nahodjashhihsja v Slede Drug za Drugom, Prikladna Gidromehanika 8(3): 16–26.

Zarrati, A. R.; Nazariha, M.; Mashahir, M. B. 2006. Reduction of Local Scour in the Vicinity of Bridge Pier Groups Using Collars and Riprap, Journal of Hydraulic Engineering 132(2): 154–162. http://dx.doi.org/10.1061/(ASCE)0733-9429(2006)132:2(154)

Ždankus, N.; Vaikasas, S.; Sabas, G. 2008. Impact of Hydropower Plant on the Downstream Reach of a River, Journal of Environmental Engineering and Landscape Management 16(3): 128–134. http://dx.doi.org/10.3846/1648-6897.2008.16.128-134

Ždankus, N.; Sabas, G. 2006. The Impact of Hydropower Plant on Downstream River Reach, Environmental Research, Engineering and Management 4(38): 24–31.

Ždankus, N.; Sabas, R. 2005. The Influence of Anthropogenic Factors to Lithuanian Rivers Flow Regime, in Proc. of the 6th International Conference “Environmental Engineering”: selected papers, vol. 1. May 26–27, 2005, Vilnius, Lithuania. Vilnius: Technika, 515‒522. ISBN 9986058503.

Ždankus, N. 2000. Influence of Reservoir on River Bed Scour. Scour of Foundations, in Proc. of an International Symposium SMGE TC-33 on Scour of Foundations. November 19, 2000, Melbourn, Australia. 380‒386, ISSMGE-TC-33.