Design Formulae of Wave Transmission due to Oblique Waves at Low Crested Structures

I Gusti Bagus Siladharma

Abstract


Abstract. Low crested structures, including submerged breakwaters, may be provided to protect the beach from wave attack. These structures can be built parallel to the shoreline and the crest is set up at or below water levels. It function is to protect the beach from wave action by reducing or by acting as a barrier to the waves. Wave transmission on structures has been subject for flume tests by many researchers and come up with several 2D wave transmission formulas. Oblique wave attack rarely involve on the formula since only a few tests conducted on 3D model. Using 3D test data conducted by Seabrook (1997), wave-structure interaction relation in 3D effect was modeled and transmission formula for low crested structures was developed. The interaction of wave-structure in the 3D modeling is more complex. The complex, three dimensional wave-structure interactions include diffraction of the wave. Results show the relative crest height, relative wave height and crest  width are the most important parameters. The model was developed by statistical analysis method, includes parameters that are considered to be representing physical processes such as water depth fluctuation, hence is related to wave breaking, wave overtopping, dissipation by surface friction, and transmission through the breakwater.

Abstrak. Pemecah gelombang ambang rendah, termasuk pemecah gelombang tenggelam, dapat dipergunakan sebagai pelindung pantai dari serangan gelombang. Stuktur dengan ambang lebar ini dibangun sejajar pantai dengan puncak berada pada muka air atau sedikit di bawahnya. Fungsi utama dari bangunan ini adalah melindungi pantai dari gelombang dengan cara mereduksi energi gelombang datang atau sebagai penghalang gelombang. Bangunan ini berfungsi dengan baik dengan meredam sebagian energi gelombang. Transmisi gelombang pada pemecah gelombang ambang rendah tumpukan batu sudah banyak diteliti dan menghasilkan beberapa formula yang dihasilkan dari tes 2 dimensi. Gelombang yang datang menyudut terhadap struktur tidak diperhitungkan karena sangat terbatasnya penelitian transmisi gelombang dalam kondisi 3D. Menggunakan data 3D dari Seabrook (1997), analisis dilakukan untuk interaksi gelombang-struktur dan formula empiris transmisi gelombang diturunkan. Interaksi gelombang-struktur dalam model 3D lebih komleks dari model 2D. Kekompleksan dalam model 3D termasuk adanya proses difraksi pada ujung-ujung pemecah gelombang, Hasil penelitian menunjukkan bahwa tinggi puncak relatif, tinggi gelombang relatif, dan lebar puncak merupakan parameter yang sangat berpengaruh terhadap proses transmisi Rumus empiris diturunkan berdasarkan analisis statistik. Rumus transmisi gelombang memasukkan parameter-parameter yang merepresentasikan proses-proses fisik seperti fluktuasi muka air, yang berkorelasi dengan gelombang pecah, overtopping gelombang, disipasi akibat gesekan permukaan, dan transmisi gelombang melalui bangunan.

Keywords


Wave transmission; Oblique waves; Low crested structures.

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References


Abdul Khader, M.H. and Rai, S.P., 1980, A Study of Submerged Breakwaters. Journal of Hydraulic Research, 18, 2: 113-121.

Ahrens, J.P. and Titus, M.F., 1985, Wave Run-up Formulas for Smooth Slopes. J. of Waterway, Port, Coastal, and Ocean Eng., ASCE, Vol. 111, No. 1, pp. 128-133.

Ahrens, J.P., 1984, Reef Type Breakwaters. Proc. of the 19th Coastal Eng. Conf., Houston, Texas, pp. 2648-2662.

Allsop, N.W.H., 1983, Low Crest Breakwater, Studies in Random Waves, Proc. of Coastal Structures ’83, Arlington-Virginia, ASCE, pp. 94-107.

Beji, S. and Battjes, J.A., 1993, Experimental Investigation of Wave Propagation Over a Bar, Coastal Engineering, 19, pp.151-162.

d’Angremond, K., van der Meer, J.W., and de Jong, R.J., 1996, Wave Transmission at Low Crested Structures, Proc. 25th Int. Conf on Coastal Engineering, pp. 3305-3318.

Dattatri, J., Raman, H. and Shankar, N.J, 1978, Performance Characteristics of Submerged Breakwater. Proc. of the 16th Conference of Coastal Engineering, Hamburg, Germany, pp.2153-2171.

Dean, R.G. and Dalrymple, R.A., 1984, Water Wave Mechanics for Engineers and Scientists, Prentice-Hall, Englewood Cliffs, N.J.

Dick, T.M. and Brebner, A., 1968, Solid and Permeable Submerged Breakwaters, Proc. of the 11th Coastal Engineering Conf., London, England, pp. 1141-1149.

Driscoll, A.M., Dalrymple, R.A. and Grilli, S.T., 1992, Harmonic Generation and Transmission Past a Submerged Rectangular Obstacle. Proc. of the 23rd Coastal Eng. Conf., Venice, Italy, pp.1142-1152.

Goda, Y, 1985, Random Seas and Design of Maritime Structures, U. Tokyo Press.

Liberatore, G. and Petti, M., 1992, Wave Transformations Over a Submerged Bar: Experiments and Theoretical Interpretations, Proc. of the 23rd Coastal Engineering Conf., Venice, Italy, pp. 447-459.

Losada, M., Kobayashi, Nobuhisa, and Martin, F.L. 1992, Armor Stability on Submerged Breakwaters.

J. of Waterway, Port, Coastal, and Ocean Eng., Vol. 118, No. 2, pp. 207-212.

Losada, M.A. and Giménez-Curto, L.A, 1981, Flow Characteristics on Rough Permeable Slopes Under Wave Action, Coastal Engineering, 4, pp. 187-206.

Miles, M.D., 1989, User Guide for GEDAP Version 2.0 Wave Generation Software, Technical Memorandum LM-HY-034, National Research Council of Canada, Ottawa.

Penney, W.G. and Price, A.T., 1952, The Diffraction Theory of Sea Waves and the Shelter Afforded by Breakwaters, Philos. Trans. R. Soc. London, Series A, 244, pp.236-253.

Petti, M. and Ruol, P., 1991. Experimental Study on the Behaviour of Submerged Detached Breakwaters. Proc. of 3rd Coastal and Port Engineering in Developing Countries, pp. 167-179.

Petti, M. and Ruol, P., 1992. Laboratory Tests on The Interaction Between Nonlinear Long Waves and Submerged Breakwaters. Proc. of the 23rd Conference Coastal Engineering, Venice, Italy, pp.792-03.

Philips, O.M., 1958, The Equilibrium Range in the Spectrum of Wind-Generated Waves, J. of Fluid Mechanics, Vol. 4, pp.426-434.

Seabrook, S.R. and Hall, K.R., 1998, Wave Transmission at Submerged Rubblemound Breakwaters, Proc. of the 26th Coastal Engineering Conf., Copenhagen, Denmark, pp. 2000-2013.

Seabrook, S.R., 1997, Investigation of the Performance of Submerged Rubblemound Breakwaters, MSc. zhesis, Queen’s University, Kingston, Canada.

Siladharma, IGB., 2001, A Study of Transmission, Reflection and Stability of Low Crested Rubble Mound Breakwaters under Waves Action, Dalhousie University, Halifax, NS, Canada Seelig, W.N., 1980, Two-dimensional Tests of Wave Transmission and Reflection Characteristics of Laboratory Breakwaters, Technical Report, No. 80-1, CERC, Vicksburg, Miss.

Sorensen, R.M., 1993, Basic Wave Mechanics for Coastal and Ocean Engineers, Wiley, New York.

Van der Meer, J.W. and F.R. Daemen, 1994, Stability and Wave Transmission at Low Crested Rubble Mound Structures, J. of Waterway, Port, Coastal, and Ocean Eng., ASCE, Vol. 121, No. 1, pp. 1-19.

Van der Meer, J.W., 1991, Stability and Transmission at Low Crested Structure, Delft Hydraulics Publication No. 453.

Wiegel, R.L., 1962, Diffraction of Waves by a Semiinfinite Breakwater, J. of Hydraulic Div. ASCE, pp. 27-44.


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