How to search?
advanced search

Search results

Filters

  • Journals
  • Authors
  • Keywords
  • Date
  • Type

Search results

Number of results: 9
items per page: 25 50 75
Sort by:

Engineering forecasting of the local scour around the circular bridge pier on the basis of experiments

Sławomir Bajkowski Marta Kiraga Janusz Urbański
Archives of Civil Engineering | 2021 | vol. 67 | No 3 | 469-488 | DOI: 10.24425/ace.2021.138066
Keywords bridge pier scour forecast model calculations
Download PDF Download RIS Download Bibtex

Abstract

The aim of the study was to indicate the procedure of using laboratory physical model tests of scour around bridge piers for the purposes of determining the potential scour of a riverbed on field bridge crossings. The determination of the uniform modeling scale coefficient according to the criterion of reliable sediment diameter limits the application of the results of tests on physical models to selected types of sediment. The projected depths of scouring of the riverbed at the pier in nature were determined for an object reproduced in the scale of 1:15 determined from the relationship of flow resistance, expressed by hydraulic losses described by the Chézy velocity coefficient, the value of which, in the model and in nature, should be the same. Expressing the value of the Chézy velocity coefficient with the Manning roughness coefficient and introducing the Strickler parameter, it was shown that the coarse sand used in the laboratory bed models the flow resistance corresponding to the resistance generated by gravel in nature. The verification of the calculated size of scouring was based on popular formulas from Russian literature by Begam and Volčenkov [16], Laursen and Toch’s [20] from the English, and use in Poland according to the Regulation ... (Journal of Laws of 2000, No. 63, item 735) [32].
Go to article

Bibliography


[1] A. A. ven Te Chow, ”Open-Bed Hydraulics,” New York: McGraw-Hill Book Company, 1959.
[2] A. Duchaczek, D. Skorupka, “Evaluation of Probability of Bridge Damage as a Result of Terrorist Attack,” Archives of Civil Engineering, vol. 2, pp. 215–227, Jun. 2013. https://doi.org/10.2478/Ace-2013-0011
[3] A. Radecki-Pawlik, P. A. Carling, E. Słowik-Opoka, R. Breakspeare, “On sand-gravel bed forms investigation within the mountainous river,” Infrastruktura i Ekologia Terenów Wiejskich, vol. 3, pp. 119–134, 2005.
[4] A. Szuster, B. Utrysko, ”Hydraulika i podstawy hydromechaniki,” Warszawa: Wydawnictwo Politechniki Warszawskiej, 1986.
[5] B. Hodi, “Effect of Blockage and Densimetric Froude Number on Circular Bridge Pier Local Scour,” in Electronic Theses and Dissertations, vol 79, Windsor, Ontario, Canada, 2009.
[6] B. Liang, S. Du, X. Pan, L. Zhang, “Local Scour for Vertical Piles in Steady Currents: Review of Mechanisms, Influencing Factors and Empirical Equations,” Journal Marine Science Engineering, vol. 8, pp. 4–27, Dec. 2020. https://doi.org/10.3390/jmse8010004
[7] B. Melville, “The Physics of Local Scour at Bridge Pier,” in Fourth International Conference on Scour and Erosion, Civil and Environmental Engineering, The University of Auckland, Auckland, vol. K-2, pp. 28–40, 2008.
[8] B. Utrysko, S. Bajkowski, L. Sz. Dąbkowski, „Światła mostów i przepustów. Zasady obliczeń z komentarzem i przykładami,” Wrocław – Żmigród: Instytut Badawczy Dróg i Mostów, Poland, 2000.
[9] D. Panici, G. A. M. De Almeida, “Formation, growth, and failure of debris jams at bridge piers,” Water Resources Research, vol. 54, pp. 6226–6241, Aug. 2018. https://doi.org/10.1029/2017WR022177
[10] D. Poggi, N. O. Kudryavtseva, „Non-Intrusive Underwater Measurement of Local Scour Around a Bridge Pier,” Water, vol. 11, pp. 2063–2074, Oct. 2019. https://doi.org/10.3390/w11102063
[11] G. J. C. M. Hoffmans, H. J. Verheij, “Scour Manual,” Rotterdam: A. A. Balkema, 1997.
[12] H. D. Copp, J. P. Johnson, “Riverbed Scour at Bridge Pier,” Final Report WA-RD 118.1. Washington State Department of Transportation, Technical Report Standard Title Page, Washington State Department of Transportation. Planning. Research and Public Transportation Division in cooperation with the United States Department of Transportation, Pullman: Federal Highway Administration, 1987.
[13] H. D. Copp, J. P. Johnson, J. L. Mcintosh, “Prediction methods for local scour at intermediate bridge piers,” Transportation Research Record, vol. 1201, pp. 46–53, 1988.
[14] H. N. C. Breusers, A. J. Raudkivi, “Scouring. Hydraulic Design Considerations. Hydraulic Structures Design Manual,” London & New York: Association For Hydraulic Research Association 2. Taylor & Francis Group, 1991.
[15] J. Schalko, C. Lageder, V. Schmocker, V. Weitbrecht, R. M. Boes, “Laboratory Flume Experiments on the Formation of Spanwise Large Wood Accumulations: Part II–Effect on local scour,” Water Resources Research, vol. 55, pp. 4871–4885, May 2019. https://doi.org/10.1029/2019WR024789
[16] L. G. Begam, G. Volčenkov, “Vodopropusknaâ sposobnost’ mostov i trub,” Moskva: Transport, 1973.
[17] L. Sz. Dąbkowski, J. Skibiński, A. Żbikowski, „Hydrauliczne podstawy projektów wodnomelioracyjnych,” Warsaw: Państwowe Wydawnictwo Rolnicze i Leśne, 1982.
[18] M. Kiraga, “Local scour modelling on the basis of flume experiments,” Acta Scientiarum Polonorum Architectura, vol. 18, no. 4, pp. 15–26, Mar. 2019. https://doi.org:10.22630/ASPA.2019.18.4.41
[19] M. Kiraga, J. Urbański, S. Bajkowski, ”Adaptation of Selected Formulas for Local Scour Maximum Depth at Bridge Piers Region in Laboratory Conditions,” Water, vol. 12, pp. 2663–2682, Sept. 2020. https://doi.org/10.3390/w12102663
[20] M. Laursen,. A. Toch, ”Scour around piers and abutments,” Bulletin 4, Iowa: Iowa Highway Research Board, USA, 1956.
[21] M. R. Namaee, J. Sui, “Impact of armour layer on the depth of scour hole around side-by-side bridge piers under ice-covered flow condition,” Journal of Hydrology and Hydromechanics, vol. 67, no. 3, pp. 240–251, Jul. 2019. https://doi.org/10.2478/johh-2019-0010-240
[22] M. S. Fael, G. Simarro-Grande, J. P. Martı´n-Vide, A. H. Cardoso, “Local scour at vertical-wall abutments under clear-water flow conditions,” Water Resources Research, vol. 42, pp. 10408–10428, Oct. 2006. https://doi.org/10.1029/2005WR004443
[23] M. van Der Wal, G. Van Driel, H. J. Verheij, “Scour manual. Desk study”. Delft Hydraulics: Rijkswaterstaat, 1991.
[24] N. A. Obied, S. I. Khassaf, “Experimental Study for Protection of Piers Against Local Scour Using Slots,” International Journal of Engineering, vol. 32, no. 2, pp. 217–222, Mar. 2019. https://doi.org/10.5829/ije.2019.32.02b.05
[25] N. S. Cheng, M. Wei, “Scaling of Scour Depth at Bridge Pier Based on Characteristic Dimension of Large-Scale Vortex,” Water, vol. 11, pp. 2458–2466, Nov. 2019. https://doi.org/10.3390/w11122458
[26] O. Link, “Physical scale modeling of scour around bridge piers,” Journal of Hydraulic Research, vol. 57, no. 2, pp. 227–237, Jul. 2019. https://doi.org/10.1080/00221686.2018.1475428
[27] PN-B-02481: 1998 Geotechnika. Terminologia podstawowa, symbole literowe i jednostki miar. Polski Komitet Normalizacji, Miar i Jakości, Poland, 1998.
[28] PN-EN ISO 14688-1: 2006 Badania geotechniczne. Oznaczanie i klasyfikowanie gruntów. Część 1: Oznaczanie i opis. Polski Komitet Normalizacyjny, Poland, 2006.
[29] PN-EN ISO 14688-2: 2006 Badania geotechniczne. Oznaczanie i klasyfikowanie gruntów Część 2: Zasady klasyfikowania. Polski Komitet Normalizacyjny, Poland, 2006.
[30] R. Chavan, P. Gualtieri, B. Kumar, “Turbulent flow structures and scour hole characteristics around circular bridge piers over non-uniform sand bed beds with downward seepage,” Water, vol. 11, no. 8, pp. 1580–1597, Jul. 2019. https://doi.org/10.3390/w11081580
[31] R. W. P. May, J. C. Ackers A. M. Kirby, “Manual on scour at bridges and other hydraulic structures”. London: CIRIA C551, UK, 2020.
[32] Rozporządzenie z dnia 30 maja 2000 r. Ministra Transportu i Gospodarki Morskiej z dnia 30 maja 2000 roku w sprawie warunków technicznych, jakim powinny odpowiadać drogowe obiekty inżynierskie i ich usytuowanie (Dz.U. 2000 nr 63 poz. 735). Regulation... (Journal of Laws 2000 No. 63 item 735).
[33] S. Bajkowski, “Effect of the Siekierka bridge on the flood flow on Zwoleńka river,” Wiadomości Melioracyjne i Łąkarskie, vol. 58, no. 1, pp. 23–29, 2015.
[34] S. Oh Lee, S. Ho Hong, “Turbulence Characteristics before and after Scour Upstream of a Scaled-Down Bridge Pier Model,” Water, vol. 11, pp. 1900–1914, Sept. 2019. https://doi.org/:10.3390/w11091900
[35] S. Bajkowski, “Bed load transport through road culverts,” Scientific Review Engineering and Environmental Sciences, vol. 2, no. 40, pp. 127–135, 2008.
[36] J. Urbański, “Influence of turbulence of flow on sizes local scour on weir model,” Acta Scientiarum Polonorum Architectura, vol. 7, no. 2, pp. 3–12, 2008.
[37] W.-G. Qi, F.-P. Gao, “Physical modeling of local scour development around a large-diameter monopile in combined waves and current,” Coastal Engineering, vol. 83, pp. 72–81, Jan. 2014. https://doi.org/10.1016/j.coastaleng.2013.10.007
[38] W. Majewski, ”Hydrauliczne badania modelowe inżynierii wodnej,” Seria publikacji naukowo-badawczych IMGW-PIB, Instytut Meteorologii i Gospodarki Wodnej Państwowy Instytut Badawczy, Poland, 2019.
Go to article

Authors and Affiliations

Sławomir Bajkowski
1
ORCID: ORCID
Marta Kiraga
1
ORCID: ORCID
Janusz Urbański
1
ORCID: ORCID
  1. Warsaw University of Life Sciences WULS-SGGW, Institute of Civil Engineering, ul. Nowoursynowska 159, 02-787 Warsaw, Poland

The study of the local scour behaviour due to interference between abutment and two shapes of a bridge pier

Noor A.A. Muhsen Saleh I. Khassaf
Journal of Water and Land Development | 2022 | No 55 | 240-250 | DOI: 10.24425/jwld.2022.142327
Keywords local scour pier shape scour interference spacing effect vertical wall abutment
Download PDF Download RIS Download Bibtex

Abstract

Although the complexities and irrevocable consequences associated with bridge scour have attracted researchers interest, their studies scarcely indicated the effect of a bridge pier proximity to an abutment. This research aims to measure maximum scour depth and exhibit the impact of pier-abutment scour interference based on laboratory experiments where vertical-wall abutment and two shapes of a pier (oblong and lenticular) were used at three different spacings (23.5, 16.0, 9.0 cm). The results showed an obvious increase in the scour depth ratio when increasing flow intensity, Froude number, and a decreasing flow depth. They also showed that reduced pier-abutment spacing was accompanied by increase in pier scour for both shapes while decrease in abutment scour. The maximum scour depth that caused by an oblong shape was more than a lenticular shape by about 10.8%. Furthermore, new empirical equations were derived using IBM SPSS Statistics 21 with determination coefficients of 0.969, 0.974, and 0.978 for oblong, lenticular and abutment, respectively. They showed the correlation between predicted and observed data.
Go to article

Authors and Affiliations

Noor A.A. Muhsen
1
ORCID: ORCID
Saleh I. Khassaf
1
ORCID: ORCID
  1. University of Basrah, College of Engineering, Department of Civil Engineering, Center of Basrah, PO Box 49, Al Basrah, Iraq

Assessment of submerged floor water jets to minimize the scour downstream from a stepped spillway

Mohamed M. Ibrahim Al Sayed Ibrahim Diwedar Ahmed Mahmoud Ibraheem
Journal of Water and Land Development | 2021 | No 50 | 122-129 | DOI: 10.24425/jwld.2021.138167
Keywords floor jets flume jet rows stepped spillway scour depth scour length
Download PDF Download RIS Download Bibtex

Abstract

Because of hydraulic jump, the scour downstream a stepped spillway is the most confusing issue that endangers the overall stability of the spillway. In this paper, thirty-six exploratory runs are described to explore the impact of utilizing submerged water jets fixed in the stilling basin of a stepped spillway on the downstream scour measurements under various flow conditions. A smooth apron where the water jets are disabled is incorporated to characterize the impact of adjustments studied. Trials are performed utilizing different upstream discharges, jets arrangements, and tailwater depths. The results are analyzed and graphically presented. The experimental data are contrasted to a scour formulae developed by other specialists. Outcomes indicated that by utilizing submerged floor water jets, the maximum scour depth is decreased between 14.3 and 36.0%. Additionally, the maximum scour length is reduced by 9.7 to 42.3%. Finally, involving regression analysis, simple formulas are developed to estimate different scour parameters.
Go to article

Authors and Affiliations

Mohamed M. Ibrahim
1
ORCID: ORCID
Al Sayed Ibrahim Diwedar
2
ORCID: ORCID
Ahmed Mahmoud Ibraheem
2
ORCID: ORCID
  1. Benha University, Shoubra Faculty of Engineering, PO box 11629 Shoubra, Egypt
  2. National Water Research Center, Hydraulics Research Institute, P.O.Box 74, Shoubra El-Kheima 13411, Egypt

Possibile Recycling of Spent Filter Backwash

Marina Valentukeviciene
Archives of Environmental Protection | 2008 | vol. 34 | No 3 | 223-228
Keywords spent filters air-scour backwash sedimentation backwash water recycling
Download PDF Download RIS Download Bibtex

Abstract

Spent-filter backwash water is usually discharged into sewers or returned to the head of a water treatment plant (WTP) to be re-processed. The purpose of this study was to characterize and compare two different WTP filter backwash water contents that were obtained by using conventional and air scour backwash methods, and influence the recycling of spent-filter backwash water. For this purpose, the spent-filter backwash water was analyzed at two different Lithuanian WTPs i.e. one using a conventional backwash method and another using an air scour backwash method (Eades, 2001). The impact of recycling spent-filter backwash on the treated water's quality was evaluated by comparing the concentration of the total iron content with suspended solids in the filtered water by following legislation rules. Backwash water in this research contained a significant concentration of total iron and a large amount of suspended solids. In this study it was found that, conventional sedimentation by gravity was sufficient for the removal of suspended solids and iron from the backwash water. Further, the presence of analyzed chemical compounds accumulating into the backwash water after sedimentation had no significant impact on the filtration's effectiveness. Therefore, this research shows that air-scour backwash water can be recycled in the same way as conventional backwash water, but a different sedimentation rate needs to be evaluated.
Go to article

Authors and Affiliations

Marina Valentukeviciene

Study the local scour around different shapes of single submerged groyne

Budoor M. Rashak Saleh I. Khassaf
Journal of Water and Land Development | 2020 | No 47 | 1-9 | DOI: 10.24425/jwld.2020.135025
Keywords bed materials bed topography pattern local scour single submerged groyne
Download PDF Download RIS Download Bibtex

Abstract

River training structures; such as submerged groynes are low profile linear structures that are generally located on the outside bank to form groynes fields and prevent the erosion of stream banks by keeping a flow away from it. In the present research, the maximum scour depth was measured based on laboratory experiments where different shapes of submerged groynes (I-shape, L-shape, T-shape) were used as sort of countermeasures to investigate about most shapes that reduce the scour around them. The result of submerged groynes showed a clear decrease in scour depth ratio due to increasing sub-merged ratio and increase the scour hole geometry with increasing of flow intensity, and also Froude number. The maxi-mum scour hole in this research was observed at T-shape groyne and then followed by I-shape groyne and L-shape groyne. The maximum scour depth that cased by I-shape was more than L-shape by a percentage about 8.2%, and it was less than T-shape by a percentage about 16.4%.

Go to article

Authors and Affiliations

Budoor M. Rashak
Saleh I. Khassaf
ORCID: ORCID

Experimental investigation of local scour under two oblong piers of a bridge crossing a sharp bend river

Abdulrazaq K. Abdulwahd Jaafar S. Maatooq
Journal of Water and Land Development | 2023 | No 58 | 129-135 | DOI: 10.24425/jwld.2023.146605
Keywords intensity of flow local scour oblong pier sharp bend
Download PDF Download RIS Download Bibtex

Abstract

Bridges built across a river bend and supported by more than one pier has been experimentally studied regarding the shape and nature of erosion and deposition. For this purpose, a U-shaped laboratory channel was used with two oblong piers installed at different locations. The first one was at the mid-section of the upstream straight reach, whereas in the second site within the bend, the piers have been installed at sections of central angles 0°, 30°, 60°, 90°, 120°, 150°, 170°, and 180°, from the beginning to the end of the bend segment respectively. The studies were conducted under clear water and threshold flow conditions. The results show that the higher and lower values of local scour around the pier positioned close to the outer bank, are 1.803 and 0.623 times the pier width when the bridge was installed at an angle of 90° and 30° respectively. As for the pier close to the inner bank, the deepest local scour was 1.786 times of the pier width when the bridge was installed at 60° of the bend, while the least one was 0.516 times of the pier width when the bridge was located in the 180° sector. It is worth noting that the presence of piers within sector 150 is less affected by local scour than in the other sections.
Go to article

Authors and Affiliations

Abdulrazaq K. Abdulwahd
1
ORCID: ORCID
Jaafar S. Maatooq
1
ORCID: ORCID
  1. University of Technology, Civil Engineering Department, Al-sina’a St, P.O Box 19006, Baghdad, Iraq

Experimental and numerical investigation of scour downstream contracted spillways

Tarek H. Nasralla
Journal of Water and Land Development | 2022 | No 52 | 53-59 | DOI: 10.24425/jwld.2021.139943
Keywords buffers contraction downstream Flow 3D scour spillway
Download PDF Download RIS Download Bibtex

Abstract

A study of scour downstream of free hydraulic jump in stilling basin of stepped spillways was carried out. This paper employed an experimental study to investigate the stepped spillway with the movable bed material of D50 = 3.1 mm. The effect of the contraction ratio of the stepped spillway was highlighted. Different downstream divergent angle was studied to minimise the scour depth, the results showed that the relative scour depth was reduced by 23% for divergent angle is equal to 170°, different shapes of buffer in stilling basin were also studied to reduce the scour depth where the considered buffer decrease the relative scour depth up to 84%. This study was simulated by Flow 3D program to analyse the scour hole formed using velocity vectors at the bed. The simulated results well agreed with the measured data.
Go to article

Bibliography

ABDELHALEEM F.S. 2013. Effect of semi-circular baffle blocks on local scour downstream clear-overfall weirs. Ain Shams Engineering Journal. Vol. 4 p. 675–684. DOI 10.1016/j.asej.2013.03.003.
ABDELHALEEM F.S. 2016. Discharge estimation for submerged parallel radial gates. Flow Measurement and Instrumentation. Vol. 52 p. 240–245. DOI 10.1016/j.flowmeasinst.2016.11.001.
ABDELHALEEM F.S. 2017. Hydraulics of submerged radial gates with a sill. ISH Journal of Hydraulic Engineering. Vol. 23(2) p. 177–186. DOI 10.1080/09715010.2016.1273798.
ABDELHALEEM F.S., AMIN A.M., BASIOUNY M.E., IBRAHEEM H.F. 2020. Adaption of a formula for simulating bedload transport in the Nile River, Egypt. Journal of Soils and Sediments. Vol. 20(3) p. 1742–1753. DOI 10.1007/s11368-019-02528-8.
AWAD A.S., NASR-ALLAH T.H., MOHAMED Y.A., ABDEL-AAL G.M. 2018. Minimizing scour of contraction stepped spillways. Journal of Engineering Research and Reports. Vol. 1(1), 41543 p. 1–11. DOI 10.9734/jerr/2018/v1i19779.
AYTAC S., GUNAL M. 2008. Prediction of scour downstream of grad control structures using neural networks. Journal of Hydraulic Engineering. Vol. 10(11) p. 1656–1660. DOI 10.1061/(ASCE)0733-9429(2008)134:11(1656).
AZAMATHULLA H.M., DEO M.C., DEOLALIKAR P.B. 2006. Estimation of scour below spillways using neural networks. Journal Hydraulic Research, International Association Hydraulic Research. Vol. 44 (1) p. 61–69. DOI 10.1080/00221686.2006.9521661.
BAGHDADI K.H. 1997. Local scour downstream drop structure. Alexandria Engineering Journal. Vol. 36. No. 2.
BORMANN N.E., JULIEN P.Y. 1991. Scour downstream of grade-control structures. Journal of Hydraulic Engineering. Vol. 117(5) p. 579– 594. DOI 10.1061/(ASCE)0733-9429(1991)117:5(579).
CHANSON H. 2001. The hydraulics of stepped chutes and spillways. Lisse, The Netherlands. Balkema. ISBN 90-5809-352-2 pp. 418.
CHANSON H., GONZALEZ C.A. 2004. Stepped spillways for embankment dams. Review, progress and development in overflow hydraulic. In: Hydraulics of dams and river structures. Eds. F. Yazdandoost, J. Attari. Proceedings of the International Conference. Tehran, Iran, 26–28 April 2004. London. Taylor & Francis Group p. 287– 294. DARGAHI B. 2003. Scour development downstream of a spillway. Journal of Hydraulic Research. Vol. 41(4) p. 417–426. DOI 10.1080/00221680309499986.
EL-MASRY A.A, SARHAN T.E. 2000. Minimization of scour downstream heading-up structure using a single line of angle baffles. Engineering Research Journal. Vol. 69 p. 192–207.
ELNIKHELY E.A. 2016. Minimizing scour downstream of spillways using curved vertical sill. International Water Technology Journal. Vol. 6. No. 3.
KOOCHAK P., BAJESTAN M.S. 2016. The effect of relative surface roughness on scour dimensions at the edge of horizontal apron. International Journal of Sediment Research. Vol. 31(2) p. 159– 163. DOI 10.1016/j.ijsrc.2013.02.001.
NAJAFZADEH M., BARANI G.A., KERMANI M.R. 2014. Group method of data handling to predict scour at downstream of a ski-jump bucket spillway. Earth Science Informatics. Vol. 7(4) p. 231–248. DOI 10.1007/s12145-013-0140-4.
NOVAK P.J. 1961. Influence of bed load passage on scour and turbulence downstream of stilling basin. Congress, IAHR, Dubrovnik, Croatia.
OLIVETO G., COMUNIELLO V. 2009. Local scour downstream of positive- step stilling basins. Journal of Hydraulic Engineering. Vol. 135 (10) p. 846–851. DOI 10.1061/(ASCE)HY.1943-7900.0000078.
PETERKA A.J. 1978. Hydraulic design of stilling basin and energy dissipaters [online]. A Water Resources Technical Publication. Engineering Monograph. No. 95. Denver. U.S. Dept. of the Interior. Bureau of Reclamation. [Access 12.12.2020]. Available at: https://www.usbr.gov/tsc/techreferences/hydraulics_lab/pubs/ EM/EM25.pdf
PILLAI N.N. 1989. Hydraulic jump type stilling basin for low Froude numbers. Journal of Hydraulic Engineering. Vol. 115(7) p. 989– 994. DOI 10.1061/(ASCE)0733-9429(1989)115:7(989).
Go to article

Authors and Affiliations

Tarek H. Nasralla
1
  1. Benha University, Benha Faculty of Engineering, Civil Engineering Department, 13512, Benha, Qalubiya, Egypt

The Impact of Energy Dissipation Devices on the Size of Local Scour Beds on the Sluice Gate Model

Janusz Urbański Marta Justyna Kiraga Sławomir Bajkowski
Archives of Civil Engineering | Vol. 66 | No 4 | 507-524 | DOI: 10.24425/ace.2020.135234
Keywords local scouring hydraulic model studies energy dissipation devices sluice gate
Download PDF Download RIS Download Bibtex

Abstract

The article presents the results of experimental research aimed at recognizing the impact of the design of energy dissipation devices on the formation of bed local scouring below the sluice gate. The experiments were carried out on a model of a sluice gate built in a rectangular flume with a width of 0.58 m, with the outflow of the stream from under the slider to a horizontal bed 0.80 m long. Behind the dam gate valve three different constructions of energy dissipation devices were used: flat, horizontal slab, slab equipped with baffle blocks arranged in two rows and rip-rap. The experiments assumed forming a scour hole in 480 minutes downstream the sluice, where the bed was filled with sorted sand. The depths of the scour were measured in the longitudinal profile after 30, 60, 90, 120, 180, 240, 300, 360, 420 and 480 minutes. The deepest scour holes of the bed, both in terms of depth and length, occurred on the structure model with energy dissipation devices made as a flat, horizontal plate. At the same time, in this case, the hole was developing the most rapidly, and its shape and size posed the greatest threat to the stability of the structure. The use of baffle blocks arranged in two rows or a rip-rap behind the structure slide noticeably reduced the size of the scour and delayed the erosion of the bottom in time, as compared to the course of this process on a model with a flat, horizontal slab.

Go to article

Authors and Affiliations

Janusz Urbański
ORCID: ORCID
Marta Justyna Kiraga
Sławomir Bajkowski
ORCID: ORCID

Bridge headwater afflux estimation using bootstrap resampling method

Marta Kiraga Sławomir Bajkowski Janusz Urbański
Archives of Civil Engineering | 2023 | vol. 69 | No 1 | 21-37 | DOI: 10.24425/ace.2023.144157
Keywords local scour sediment hydraulic structures hydraulics flood bridge engineering
Download PDF Download RIS Download Bibtex

Abstract

The bridge structure’s development causes a riverbed cross-sections contraction. This influences the flow regime, being visible during catastrophic floods. Then the flow velocity increases and water piles up upstream the bridge, where headwater afflux could be observed. These changes depend on the watercourse geometry and the bridge cross-section properties, especially on the degree of flow contraction under the bridge. Hydraulic conditions under the bridge depend on flow velocity, dimensions, and shape of abutments, the granulometric composition of bedload, which can be quantitatively characterized by hydraulic resistance coefficients. The research subject of headwater afflux is equated with the recognition of morphodynamic processes occurring along the passage route. The headwater afflux could be estimated by empirical formulas and by the energy method using Bernoulli’s law. Empirical methods are optimized by adopting various statistical criteria. This paper compares the headwater afflux values calculated using two existing empirical formulas, Rehbock and Yarnell, and compares them with the results of laboratory tests. Following the assumption that the free water surface is influenced by flow resistance, an attempt was made to include friction velocity in the empirical formulas. Based on the Authors’ database, the coefficients used were optimized using bootstrap resampling in Monte Carlo simulation. The analyses demonstrated that the formula best describing the phenomenon of headwater afflux upstream the bridge is an empirical formula built based on the historical Yarnell formula, which includes friction velocity value. The optimized equation provides an average relative error of 12.9% in relation to laboratory observations.
Go to article

Authors and Affiliations

Marta Kiraga
1
ORCID: ORCID
Sławomir Bajkowski
1
ORCID: ORCID
Janusz Urbański
1
ORCID: ORCID
  1. Warsaw University of Life Sciences, Institute of Civil Engineering, Faculty of Civil and Environmental Engineering, ul. Nowoursynowska 159, 02-776 Warsaw, Poland

This page uses 'cookies'. Learn more