Antonio Corredor, Rafael Torres, Juan Vicente Miñana, Enrique Fernández, Carlos Fermín Menéndez, Moisés Santos, M. Esther Gómez-Martín, Josep R. Medina


The structural strength of concrete armor units (CAUs) is a key factor in the design and construction of armor layers for large mound breakwaters. This paper describes the prototype drop tests carried out to assess the structural strength of conventional cube and Cubipod CAUs. Low intensity overturning tests, high intensity free fall tests and extreme intense free fall tests were conducted to measure the structural integrity under impact loads of the Cubipod CAU
compared to the conventional cubic block. The casting systems and pressure clamps were specifically designed to manufacture and handle the 15-tonne conventional cube and 16-tonne Cubipod prototypes used for the drop tests.
Two reinforced-concrete platforms were used for overturning and free fall tests. The 16-tonne Cubipod prototypes withstand drops more than 50% higher than 15-tonne conventional cube prototypes of similar concrete strength. Two extreme free fall tests verified the robustness of Cubipod prototypes in accidental falls during construction. Both Cubipod and conventional cube CAUs have similar stacking and handling procedures as well as manufacturing cycle


rubble-mound breakwater; armor unit; Cubipod; drop test; prototype test; concrete block

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Burcharth, H.F. 1981. Full scale dynamic testing of dolosse to destruction. Coastal Engineering, 4(3), 229-251.

Burcharth, H.F., and T. Brejnegaard-Nielsen. 1986. The influence of waist thickness of dolosse on the hydraulic stability of dolosse armour. Proceedings of 20th International Conference on Coastal Engineering, ASCE, 1783-1796.

Burcharth, H.F., K. d'Angremond, J.W. Van der Meer, and Z. Liu. 2000. Empirical formula for breakage of dolosse and tetrapods. Coastal Engineering, 40(3), 183-206.http://dx.doi.org/10.1016/S0378-3839(00)00010-7

Burcharth, H.F., E. Maciñeira, and P. Canalejo. 2002. Model testing and reliability evaluation of the new deepwater breakwater at la Coruña, Spain. Proceedings of 27th International Conference on Coastal Engineering, ASCE, 1581-1593.

Corredor, A., R. Torres, J.V. Miñana, E. Fernández, C.F. Menéndes, M. Santos, M.E. Gómez-Martín, R. Goumy, and J.R. Medina. 2008. CUBÍPODO: Estudios de estabilidad hidráulica 2D y 3D, estudio del remonte y rebase, diseño del encofrado y ensayos de caída de prototipos. Libro del III

Congreso Nacional de la Asociación Técnica de Puertos y Costas, Puertos del Estado, 187-211 (in Spanish).

Dupray, S., and J. Roberts. 2009. Review of the use of concrete in the manufacture of concrete armour units. Proceedings of Coasts, Marine Structures and Breakwaters 2009, ICE (in press).

Gómez-Martín, M.E., and J.R. Medina. 2008. Erosion of cubes and Cubipods armour layers under wave attack. Proceedings of 30th International Conference. on Coastal Engineering, ASCE, 3461-3473.

Hakenberg, R., I. Vos-Rovers, J.S. Reedijk, and M. Muttray. 2004. Structural Integrity of the Xbloc® breakwater armour units prototype and numerical droptests. Proceedings of 29th International Conference, ASCE, 4507-4520. Hanzawa, M., T. Kato, Y. Kishira, Y. Ozawa, Y. Niidome, T. Murakami, A. Ono, K. Hidaka, H.

Yoshida, and I. Tanaka. 2006. Fully reinforced 80t Dolos and sloping top caisson in Hososhima Port. Proceedings of 30th International Conference on Coastal Engineering, ASCE, 4805-4814.

Muttray, M., J.S. Reedijk, I. Vos-Rovers, and P. Bakker. 2005. Placement and structural strength of Xbloc® and other single layer armour units. Proceedings of Coastlines, Structures and Breakwaters 2005, ICE, 556-567.

Nishigori, W., T. Endo, K. Nemoto, Y. Noguchi, and M. Yamamoto. 1989. Similarity law of impact between model and prototype tetrapods, in Stresses in Concrete Armor Units, edited by Davidson D.D., and O.T. Magoon, ASCE, 107-122.

Silva, M.A.G. 1983. On the mechanical strength of cubic armour blocks. Proceedings of Coastal Structures '83, ASCE, 259-271.

DOI: https://doi.org/10.9753/icce.v32.structures.43