April 12, 2012

Vermelding onderdeel organisatie

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Chapter 2: Positioning the subject

ct5308 Breakwaters and Closure Dams

H.J. Verhagen

Faculty of Civil Engineering and GeosciencesSection Hydraulic Engineering

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Focus on:• Technical aspects• Technical impacts only

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Breakwaters and Closure dams

• Comparable items:• similar materials• similar execution methods

• Differences:• load difference (wave action vs. currents)• life time

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Characteristic values

Type of structure H/Δdn

Sandy beachGravel beachRock slopeBerm breakwater(Stable) rubble mound breakwatercaisson

>50020-5006-203-61-4<1

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mound breakwater types

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Monolithic breakwater type

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Sometimes vertical wall is only option

Cardiff Barrage14 m tidal range(situation at high water

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Composite breakwater types

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Special breakwater types

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Floating breakwater in Italy(Marina di Verbania, Lago Maggiore)

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Floating breakwater in Italy

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Floating breakwater in Italy

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Vertical screens(Royal Prince Alfred Yacht Club, Sydney, Australia)

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Basic methods of closure

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Closure named after topography

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Closures named after hydrologic conditions

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closures named after materials used

• stacking up willow mattresses (opzinken)

• sand closure• clay or boulder clay closure• stone dam closure (rock closure)• caisson closure

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Pluimpot, Tholen

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sand closure

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Afsluitdijk

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rock closure

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caisson closure

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Rubble mound breakwater at Cittavecchia

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Breakwater at Cherbourg

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Breakwater at Plymouth

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Monolithic breakwater at Dover

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Breakwater at Marseilles

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Typical breakwater along the Mediterranean coast

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Historical closures

• Rhine damming (Wijk bij Duurstede)• Sloe closure (pakwerk)• Hindeburgdam

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Walcheren, four gaps on one island

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Development of erosion gullies