Patrick Mulders, Henk Jan Verhagen


A new series of physical model tests were conducted to analyse the behaviour of a breakwater core when it becomes exposed to wave attack. The emphasis of this research was on the measured influence of a wide stone grading on both the deformation of a breakwater trunk and the occurring longshore transport. This behaviour was investigated for both head-on and oblique waves using two different wave loads. The findings were compared to the currently available formulas and the validity of these formulas for the tested range of parameters was (re)checked. In general a clear distinction was found in the processes between tests with narrow grading and wide grading. It turned out that both the parameters describing the two-dimensional deformation and the longshore transport show an increase for wider grading.


rubble-mound breakwater; core; grading; physical model test; two-dimensional deformation; stone displacement; longshore transport

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Alikhani, A., G.R. Tomasicchio and J. Juhl. 1996. Berm breakwater trunk exposed to oblique waves, Proceedings of 25th International Conference on Coastal Engineering, ASCE, 1528-1541.

Hall, K.R. and J.S. Kao. 1991. The influence of armour stone gradation on dynamically stable breakwaters, Coastal Engineering, 15.

Merli, D. 2009. Stability of wide-graded rubble mounds, UNESCO-IHE, Delft, MSc Thesis

Mulders, P.H.M. 2010. Breakwaters under construction exposed to oblique waves, Delft University of Technology, Delft, MSc Thesis

Pianc. 2003. State of the art of designing and construction berm breakwaters, MarCom; Report of WG 40, 2003, International Navigation Association, Brussels, Belgium, 2-87223-138-2

Tomasicchio, G.R., R. Archetti, F. D'Alessandro, P. Sloth. 2007. Long shore transport at berm breakwaters and gravel beaches, Proceedings of 5th Coastal Structures International Conference CST07, Venice, Italy.

Tomasicchio, G.R., A. Lamberti and F. Guiducci. 1994. Stone movement on a reshaped profile, Proceedings of 24th International Conference on Coastal Engineering, ASCE, 1625-1640.

Van der Meer, J.W. 1988. Rock slopes and gravel beaches under wave attack, Delft University of Technology, Delft, PhD Thesis

Van der Meer, J.W. 1992. Stability of the seaward slope of berm breakwaters, Coastal Engineering, 16, 205-234.

Van der Meer, J.W. and J.J. Veldman. 1992. Singular points at berm breakwaters: scale effects, rear, roundhead and longshore transport, Coastal Engineering, 17, 153-171.