Temiz Su Koşulları Altında Dairesel Köprü Ayaklarının Etrafındaki Nihai Oyulma Derinliklerinin Deneysel Araştırılması

Year 2019, Volume: 10 Issue: 3, 1165 - 1175, 29.09.2019

Fırat Gümgüm Ayşegül Özgenç Aksoy Mehmet Şükrü Güney

https://doi.org/10.24012/dumf.583208

Abstract

Bu deneysel çalışmada, TÜBİTAK 109M637 projesi kapsamında inşa edilen hareketli tabanlı doğrusal kanalda kararlı akım şartlarında dairesel kesitli köprü ayakları etrafındaki nihai temiz su oyulması incelenmiştir. Deneysel çalışmada 4 farklı boyutlu dairesel köprü ayağı ve 3,47 mm ortalama tane çapına sahip üniform taban malzemesi kullanılmıştır. Ultrasonik hız profilleyicisi yardımıyla ölçülen oyulma derinlikleri, literatürdeki mevcut bağıntılardan elde edilen oyulma derinlikleri ile karşılaştırılmış ve oyulma derinliği ile ilişkili bazı parametrelerin oyulma derinliğine olan etkisi incelenmiştir. Çeşitli regresyon analizleri sonucu nihai temiz su oyulma derinliğini tahmin eden bir bağıntı önerilmiş ve istatistiksel olarak anlamlı parametreler elde edilmiştir. En yüksek oyulma derinliğinin ayağın memba bölgesinde meydana geldiği gözlenmiştir. Akım şiddeti, yoğunluk farkı esaslı dane Froude sayısı ve köprü ayak çapı arttıkça oyulma derinliğinin arttığı tespit edilmiştir.

Keywords

Köprü ayağı, yerel oyulma, temiz su oyulması, kararlı akım

Supporting Institution

TÜBİTAK

Project Number

109M637

Thanks

Yazarlar finansal destek için TÜBİTAK'a (proje numarası 109M637) teşekkür ederler.

Experimental Investigation of Final Scour Depths Around Circular Bridge Piers Under Clear-Water Conditions

Abstract

In this experimental study, final scour depths around circular bridge piers under clear-water conditions were investigated within the scope of the project TÜBİTAK 109M637. Circular bridge piers with 4 different diameters and uniform bed material having median diameter of 3.47 mm were used during the experiments. The scour depths measured by means of ultrasonic velocity profilers were compared with the scour depths obtained from the present equations in the literature and the effect of some parameters related to scour depth was investigated. As a result of various regression analyses, an equation was proposed to predict the final scour depth and statistically significant parameters were obtained. The highest scour depth was observed in the upstream side of the pier. It has been found that the scour depth increases with increasing flow intensity, densimetric particle Froude Number and pier diameter.

Keywords

Bridge pier, local scour, clear water scour, steady flow

Project Number

109M637

References

• Breusers, H. N. C., Nicollet, G., Shen, H. W., (1977). Local scour around cylindrical piers, Journal of Hydraulic Resources, 15, 3, 211-252.
• Chang, W., Lai, J., Yen, C., (2004). Evolution of Scour Depth at Circular Bridge Piers, Journal of Hydraulic Engineering, 130, 9, 905–913.
• Chabert, J., Engeldinger, P., (1956). Etude des affouillements autour des piles de ponts, Serie A. Laboratoire National d’Hydraulique, 6, Quai Watier, Chatou, France.
• Chiew. Y. M., (1984). Local Scour at Bridge Piers, Doktora Tezi, The University of Auckland, Auckland.
• Dey, S., Bose, S., Sastry, G., (1995). Clear Water Scour at Circular Piers: a Model, Journal of Hydraulic Engineering, 121, 12, 869–876.
• Ettema, R. E., (1980). Scour at bridge piers, Rep. No. 236, School of Engineering, The University of Auckland, New Zealand.
• Günyaktı, A., (1988). Köprü ayakları etrafında oyulma derinliğinin grafik yöntemle tayini, Mühendislik ve Çevre Bilimleri Dergisi, TÜBİTAK, 12, 1, 96-108.
• Hancu, S., (1971). Sur le calcul des affouillements locaux dams la zone des piles des ponts. Proc., 14th /AHR Congr., Int. Assn. for Hydr. Res. (IAHR), Paris, France, 3, 299-313.
• Kothyari, U. C., Hager, W. H., Oliveto, G., (2007). Generalized approach for clear-water scour at bridge foundation elements, Journal of Hydraulic Engineering, 133, 11, 1229-1240.
• Lai, J. S., Chang, W. Y., Yen, C. L., (2009). Maximum Local Scour Depth at Bridge Piers under Unsteady Flow, Journal of Hydraulic Engineering, ASCE, 135, 7, 609-614.
• Laursen, E. M., (1958). Scour at bridge crossings, Bull. No.8, Iowa Hwy. Res. Board, Ames, Iowa.
• Melville, B. W., (1975). Local scour at bridge sites, Doktora Tezi, The University of Auckland, Auckland.
• Melville, B. W., Sutherland A.J., (1988). Design Method for Local Scour at Bridge Piers, Journal of Hydraulic Engineering, 114, 10, 1210-1226.
• Melville, B. W., (1997). Pier and abutment scour: integrated approach, Journal of Hydraulic Engineering, 123, 2, 125–136.
• Melville, B., Chiew, Y., (1999). Time Scale for Local Scour at Bridge Piers, Journal of Hydraulic Engineering, 125, 1, 59–65.
• Mia, M., Nago, H. (2003). Design Method of Time-Dependent Local Scour at Circular Bridge Pier, Journal of Hydraulic Engineering, 129, 6, 420–427.
• Oliveto, G., Hager, W. H., (2002). Temporal evolution of clear-water pier and abutment scour, Journal of Hydraulic Engineering, 128, 9, 811–820.
• Oliveto, G., Hager, W. H., (2005). Further results to time-dependent local scour at bridge elements, Journal of Hydraulic Engineering, 131, 2, 97–105.
• Raudkivi, A. I., (1986). Functional trends of scour at bridge piers, Journal of Hydraulic Engineering, ASCE, 112, 1, 1-13.
• Richardson, E.V., Davis, S.R., (2001). Evaluating scour at bridges (4th Edition), Teknik Rapor, Federal Highway Administration Hydraulic Engineering Circular No. 18, FHWA NHI 01-001.
• Sheppard, D. M., Odeh, M., Glasser, T., (2004). Large scale clear-water local pier scour experiments, Journal of Hydraulic Engineering, 130, 10, 957-963.
• Yanmaz, A. M., (1989). Time dependent analysis of clear water scour around bridge piers, Doktora tezi, Orta Doğu Teknik Üniversitesi, Ankara, Türkiye.
• Yanmaz, A., Altinbilek, H. (1991). Study of Time‐Depenbent Local Scour around Bridge Piers, Journal of Hydraulic Engineering, 117, 10, 1247–1268.
• Yanmaz, A.M., (2002). Köprü Hidroliği, Ankara: METU Press.