Hee Min Teh, Vengatesan Venugopal, Tom Bruce


The increasing importance of the sustainability challenge in coastal engineering has led to the development of free surface breakwaters of various configurations. In this study, the hydrodynamic characteristics of a perforated semicircular free surface breakwater (SCB) are investigated for irregular wave conditions. The hydrodynamic performance of the breakwater is evaluated in the form of transmission, reflection and energy dissipation coefficients, which are then presented as a function of the relative submergence depth (D/d) and the relative breakwater width (B/Lp), where D = the depth of immersion, d = the water depth, B = the breakwater width and Lp = the wavelength corresponding to the peak wave period. It is found that the wave attenuation ability of the SCB model improves with the increase of D/d and B/Lp. The SCB performs better as an energy dissipater than as a wave reflector. Based on the analysis of measured data, some empirical equations are proposed to predict the performance of the breakwater under varying submergence depths. The behaviour of wave transformation around and within the breakwater’s chamber is discussed. Also, the measured horizontal wave forces acting on the SCB are reported.


semicircular breakwater; wave transmission; wave reflection; energy dissipation; wave force


Brossard, J., Jarno-Druaux, A., Marin, F. and Tabet-Aoul, E.H. 2003. Fixed absorbing semi-immersed breakwater. Coastal Engineering, 49, 25-41.http://dx.doi.org/10.1016/S0378-3839(03)00044-9

Gőnaydın, K. and Kebdaslı, M.S. 2004. Performance of solid and perforated U-type breakwaters under regular and irregular waves, Ocean Engineering, 31, 1377-1405.http://dx.doi.org/10.1016/j.oceaneng.2004.02.002

Gőnaydın, K. and Kebdaslı, M.S. 2007. Investigation of P-type breakwater performance under regular and irregular waves. Ocean Engineering, 34, 1028-1043.http://dx.doi.org/10.1016/j.oceaneng.2006.03.015

Hsiao, S-,S., Fang. H-,M., Chang, C-,M. and Lee, T-,S. 2008. Experimental study of the wave energy dissipation due to the porous-piled structure. Proceedings of the 18th International Offshore and Polar Engineering Conference, Vancouver, Canada, 592-598.

Hu, H., Wang, K.H. and Williams, A.N. 2002. Wave motion over a breakwater system of a horizontal plate and a vertical porous wall. Ocean Engineering, 29, 373-386.http://dx.doi.org/10.1016/S0029-8018(01)00029-4

Hughes, S.A. 1993. Physical models and laboratory techniques in coastal engineering. World Scientific, Singapore.

Koftis, T. and Prinos, P. 2005. On the hydrodynamic efficiency of floating breakwaters. Arabian Coast Conference.


Koutandos, E.V. 2007. Hydrodynamic analysis of a skirt breakwater, Maritime Engineering, 160, Institute of Civil Engineers, 121-133.

Koutandos, E. and Prinos, P. 2005. Design formulae for wave transmission behind floating breakwaters, IAHR XXXI Congress, Seoul, Korea, 4081-4089.

Li, D., Panchang, V., Tang, Z., Demirbilek, Z., and Ramsden, J. 2005. Evaluation of an approximate method for incorporating floating docks in harbor wave prediction models, Canadian Journal of Civil Engineering, 32, 1082-1092.http://dx.doi.org/10.1139/l05-059

Mansard, E.P.D. and Funke, E.R. 1980. The measurement of incident and reflected spectra using a least squares method, Proceedings of the 17th International Conference on Coastal Engineering, ASCE, 154-172.

Neelamani, S. and Gayathri 2006. Wave interaction with twin plate wave barrier. Ocean Engineering, 33, 495-516.

Neelamani, S. and Rajendran, R. 2002a. Wave interaction with T-type breakwaters. Ocean Engineering, 29, 151-175.http://dx.doi.org/10.1016/S0029-8018(00)00060-3

Neelamani, S. and Rajendran, R. 2002b. Wave interaction with '^'-type breakwaters. Ocean Engineering, 29, 561-589.http://dx.doi.org/10.1016/S0029-8018(01)00030-0

Neelamani, S. and Vedagiri, M. 2002. Wave interaction with partially immersed twin vertical barriers. Ocean Engineering, 29, 215-238.http://dx.doi.org/10.1016/S0029-8018(00)00061-5

Patarapanich, M and Cheong, H. F. 1989. Reflection and transmission characteristics of regular and random waves from a submerged horizontal plate. Coastal Engineering, 13, 161-182.http://dx.doi.org/10.1016/0378-3839(89)90022-7

Sundar, V. and Subba Rao, B.V.V. 2003. Hydrodynamic performance characteristics of quadrant frontface pile-supported breakwater. Journal of Waterway, Port, Coastal and Ocean Engineering, ASCE, 22-33.http://dx.doi.org/10.1061/(ASCE)0733-950X(2003)129:1(22)

Tsay, T.-K. and Liu, P.L.-F. 1983. A finite element model for wave refraction and diffraction. Applied Ocean Research, 5(1), 30-37.http://dx.doi.org/10.1016/0141-1187(83)90055-X

Usha, R. and Gayathri, T. 2005. Wave motion over a twin-plate breakwater. Ocean Engineering, 32, 1054-1072.http://dx.doi.org/10.1016/j.oceaneng.2004.07.010

Wang, Y., Wang, G. and Li, G. 2006. Experimental study on the performance of the multiple-layer breakwater. Ocean Engineering, 33, 1829-1839.http://dx.doi.org/10.1016/j.oceaneng.2005.10.017

Full Text: PDF

Creative Commons License
This work is licensed under a Creative Commons Attribution 3.0 License.