ACCROPODE™ II" Technology, experience and cost-effectiveness condensed into a single armour unit"

"The single-layer team at your service from preliminary design through to completion of works"

ACCROPODE™II Single-layer system for breakwater armouring

BackgroundThepioneerinsingle-layertechnology,theACCROPODE™techniquehasbecomethebenchmarkformodern breakwater armouring.Feedbackfromextensiveexperienceonasubstantialnumberofsingle-layerprojectshasledtotherefinementoftheoriginalconceptanddesign.Anewarmourunit,theACCROPODE™IIhasbeenpatentedbySOGREAHin1999,further improving the practical use and cost-effectiveness.

Enhanced hydraulic performanceThe optimised shape, and roughening by means of pyramids acting as friction enhancers on the faces of these armour units, increase ACCROPODE™II interlocking, while new features include:- minimised rocking and settlement,- maximised energy dissipation,-reducedwavereflectionandrun-up/overtopping,- improved structural strength.

During thedesign stage, the stability coefficients are selected as a function of the achievable packing density on site. ThestandardHudson’sdesignKD values for breaking or non-breaking wave conditions are: • 16onbreakwatertrunksections • 12.3onbreakwaterroundheadsAlternatively, the recommended Van der Meer stability number is: NS = HS/(∆Dn50)= 2.8 where HS = Significant wave height ∆ = Relative mass density Dn50 = Nominal diameter

These coefficients are valid for armour slopes from 3H/2V to 4H/3V. However for breaking waves and a seabed slope greater than 1%, lower values shall apply.

Concretestrengthspecifications

Min. compressive strengthFc at 28 days

Min. tensile strengthFt at 28 days

Unitvolume≤15.0m3 30 MPa 3.0 MPa

Unit volume > 15.0 m3 35 MPa 3.5 MPa

3D tests

Stress contours

Improved structural robustnessComparative finite-element studies have demonstrated that theACCROPODE™II unit has improved robustness comparedwiththefirst-generationACCROPODE™, which in itself is recognized worldwide for its excellent records and reputation.

Reliable, easy formwork• Twosymmetricalsteelshells• Nobaseplatesrequired• Quick-assemblyboltingsystem• Easeofstrippingandreassembly

Simple casting• Min.arearequiredtocastoneunitofheightH:1.55H2

• Min.compressiveconcretestrengthrecommendedatstripping: 7MPaforunitslessorequalto8m3 and 10 MPa for sizes above 8 m3

• Typicaldailystandardproductionrate:oneunitpermould

Safe storage and handling by crane or forklift• Unitscanbestoredoneontopoftheotherornestedonone or more levels, provided that ground conditions are suitable• Min.arearequiredtostore10unitson1level:7.1H2

where H = ACCROPODE™II unit height • Min.compressiveconcretestrengthrecommendedforhandlingunits: 20MPaforunitslessorequalto8m3 and 25 MPa for sizes above 8 m3

Simplified placementThenewACCROPODE™II shape enables units to be placed more rapidly on site using simple rules, since the random attitude of each unit is naturally obtained, with fewer constraints in terms of orientation.The use of a safe remote-release hook is recommended for unit placement.Placement operations under water are enhanced using GPS, ensuring close adherence to the theoretical grid shown on the placement drawings and allowing reliableQA/QCprocedures.

Properpackingprovidesadequatecoverageonbreakwaterslope: where Na = Number of armour units A = Unit area of breakwater slope Ø = Packing density VaccrII = ACCROPODE™II unit volume

1.55 H

H

Mould ready for casting

Striking operation

Transport by barge

Drafting of positioning drawings

Placement using a floating crane

Plan layout of casting arrangement

NaA

= Ø VaccrII-2/3

Placement rates (using cable cranes)

Average placing time per unit

1.0 m3 ≤Unitvolume≤3.0m3 4 to 6 mins

4.0 m3 ≤Unitvolume≤8.0m3 7 to 10 mins

Unitvolume≥11.0m3 10 to 20 mins

NB:higherratescanbeobtainedusinghydraulicplacingequipmentwithsmallsizeunits.

www.concretelayer.com

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Head officeIn FranceCLI3, cours du 56, av. Marcel Dassault B.P. 510 - 37205 Tours cedex 3 - FranceTel. +33 (0)2 47 74 18 10Fax +33 (0)2 47 74 18 12michel.denechere@concretelayer.com

Other officesIn FranceSogreah Consultants6, rue de Lorraine - 38130 Echirolles - FranceTel. +33 (0)4 76 33 40 00Fax +33 (0)4 76 33 43 33michel.fons@sogreah.fr

In the U.S.Baird & Associates2981 Yarmouth Greenway Dr.Madison, WI 53711 - USATel. +1 608 273 0592Fax +1 608 273 2010dwerren@baird.com

ACCROPODE™II is a registered trademark of Sogreah Consultants - FranceACCROPODE™II armour units are protected by patents worldwideCLI is the licensee of Sogreah Consultants

ACCROPODE™ II projects investigated or built in: •Angola

•Cyprus

•France

•India

•Italy

•Mauritius

•Morocco

•Polynesia

•SouthKorea

•SriLanka

•Uruguay