Keywords
armor porosity
armor unit placement
Cubipod armor unit
cube armor unit
placement test
placement grid
crawler crane
How to Cite
Abstract
The handling procedure and placement grid of concrete armor units (CAUs) are the key construction factors of armor layers. This paper analyzes conventional cube and Cubipod CAUs which are handled by pressure clamps and placed randomly. Two methodologies for small-scale blind construction of armor layers in laboratories are compared using a Cartesian system and crawler cranes. Model construction by hand in laboratories is usually done in excellent conditions contrary to actual construction at prototype scale which is blind underwater and is influenced by wind, waves and equipment constraints. For randomly placed CAUs, the layer coefficient is an unnecessary and subjective concept which should be disregarded to prevent misunderstandings when considering armor porosity. For a given CAU, the placement grid affects armor porosity which is directly related to armor hydraulic stability. Crawler cranes can only place CAUs in a narrow armor porosity band; therefore, porosity of small scale armor models constructed by hand must be selected within that viable porosity band to avoid uncontrolled model effects. Armor layers of conventional cubes placed randomly by hand are not realistic if porosity is p%<35% and have more hydraulic stability than the higher porosity armors which can actually be constructed with crawler cranes.References
Bakker, P., M. Klabbers, M. Muttray, and A. van den Berge. 2005. Hydraulic performance of Xbloc® armour units. Proceedings of 1st International Conference on Coastal Zone Management and Engineering in the Middle East. Dubai, November 2005.
Burcharth, H.F., E. Maciñeira, and P. Canalejo. 2002. Model testing and reliability evaluation of the new deepwater breakwater at A Coruña, Spain. Proceedings of 27th International Conference on Coastal Engineering, ASCE, 1581-1593.
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).
Figueres, M., and J.R. Medina. 2004. Estimation of incident and reflected waves using a fully nonlinear wave model. Proceedings of the 29th International Conference on Coastal Engineering, ASCE, 594-603.
Frens, A.B. 2007. The impact of placement method on Antifer-block stability. M.Sc. thesis, Delft University of Technology, May 2007.
Gómez-Martin, M. E., and Medina, J. R. 2006. Damage progression on cube armoured breakwaters. Proceedings. of the 30th International Conference on Coastal Engineering, ASCE, 5229-5240.
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.
Medina, J.R., M.E. Gómez-Martín, A. Corredor, R. Torres, J.V. Miñana, E. Fernández, C.F. Menéndez, and M. Santos. 2009. Cube and Cubipod armour unit drop tests and cost analysis. Proceedings of Coasts, Marine Structures and Breakwaters 2009, ICE, (in press).
Pardo, V. 2009. Análisis de la colocación de bloques cúbicos y cubípodos en el manto principal de diques en talud. Aplicación a la ampliación del Puerto de Valencia. Proyecto Fin de Carrera de la ETSI Caminos, Canales y Puertos, Julio 2009 (in Spanish).
SPM. 1984. Shore Protection Manual, U.S. Army Corps of Engineers, Waterways Experiment Station, Coastal and Hydraulics Laboratory, Vicksburg, MS.
Yagci, O., and S. Kapdasli. 2003. Alternative placement technique for antifer blocks used on breakwaters. Ocean Engineering, 30(2003), 1433-1451.http://dx.doi.org/10.1016/S0029-8018(02)00134-8
Van der Meer, J. 1999. Design of concrete armour layers. Proceedings of the Coastal Structures ´99. A.A. Balkema, 213-221.