Physical model tests on new armour block Crablock for breakwaters to come to preliminary design guidance

In the design of rubble mound breakwaters, nowadays single layer systems using concrete armour units have become more common practice compared to conventional two layer systems. However, after the introduction of the accropode in eighties, a small number of single layer armour units have been developed over the years; for example core-loc, A...

Set-up to design guidance for the Crablock armour unit

The Crablock is a symmetrical unit, this in contrast to the units that have been applied most in the past. Essentially, this is the main difference. All other units have six “obstacles” that insure interlocking, but they are not symmetrical. All those units are placed randomly in a certain way with more or less contacts to neighbouring units. A...

De stabiliteit van stortsteengolfbrekers

Onderzoek naar de stabiliteit van armour units op breuksteengolfbrekers en havendammen, met focus op betonnen elementen. Ontwikkeling van het HARO blok, toepassing van dit blok in de haven van Zeebrugge. Onderzoek naar de hydraulische en geotechnische faalmechanismen (glijvlakken), resultaten modelonderzoek en prototype metingen in Zeebrugge van...

Stability formula for breakwaters armoured with Accropode

Delft Hydraulics has performed an extensive investigation on the stability of rubble mound revetments and breakwaters under random wave attack. Two stability formulae have been derived which describe the stability of rock slopes as a function of wave height, wave period, slope angle, storm duration, permeability and damage level. The complete...

Staticstability of rubble mound breakwaters

It is not possible to design rubble mound structures employing complex blocks entirely from first principles. Each type of armour unit exploits properties like weight, interlocking, inter-block friction etc, in varying degrees to achieve stability. This is one of the reasons that the empirical formulae often used are inadequate and why most...

Laboratory investigations of rubble-mound breakwaters

This paper reports on a laboratory investigation conducted at the United States Army Engineer Waterways experiment station, Vickburg, Mississippi, to determine criteria for the design and construction of rubble mound breakwaters. Small-scale breakwater sections are hand-constructed in a concrete wave flume 119 ft long, 5ft wide, 4 ft deep, and...