Abstract
Single layer, randomly placed, interlocking concrete units are widely used for the protection of exposed breakwaters. Based on 15 years of experience with Xbloc projects around the world, DMC started the development of an armour unit called XblocPlus. XblocPlus is a single layer concrete unit which is placed in a regular pattern. An essential part of this development were hydraulic model tests in 2D and in 3D to determine the hydraulic stability under wave loading and the overtopping volumes for the new units. These studies and the results regarding the stability, failure mechanisms and roughness coefficient are described in this paper.
Highlights
Concrete armour units are widely used for the protection of breakwaters and seawalls
FROM OVERTOPPING TESTS The EurOtop overtopping formula for rubble mounds predicts and non-dimensional overtopping rate that is primarily determined by freeboard, Rc/Hm0
The hydraulic stability of XblocPlus armoured slopes from the toe up to but not including the transition to the crest was tested in 2D and 3D hydraulic model tests
Summary
Concrete armour units are widely used for the protection of breakwaters and seawalls. Like other single layer, interlocking armour units XblocPlus is placed on a staggered grid, i.e. the position of each armour units on the breakwater slope is defined. For that reason the armour unit are placed with a uniform orientation Further to this the XblocPlus contact points are designed such that armour units are guided into the target position during placement (DMC, 2018). The contact points were optimised for interlocking During these development stages the hydraulic stability of the new armour unit were tested. The design wave height for the XblocPlus armour units tested is 9.8 cm (significant wave height, Hs) This is based on a stability number Ns = Hs/(ΔDn) of 2.5 (with relative density, Δ and nominal rock diameter, Dn).
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
