INVESTIGATION DIFFERENT TYPES OF BREAKWATERS

2.4 BREAKWATER TYPOLOGY STUDY

There are a number of different types of breakwater types. Which type best suits the specific criteria of the Grand Tour of EUtopia? An analysis of the four major types.

CALULATING WAVE PRESSURE

OPTION A: SLOPING OR RUBBLE MOUND BREAKWATER

WAVE TYPE AT THYBORØN The waves arriving on the site are non breaking as the water depth is approximately 9m deep. However, over time sand will accumulate in the breakwater and decrease the water depth.

DESCRIPTION Rubble mounds arranged in sloping hills. They are the most common method to protect harbors from waves. The seaward slop of the mound can wasily absorb wave energy.

WAVE ACTION

NON BREAKING WAVES FORCES ON VERTICAL WALLS Typically hydrostatic forces from non breaking waves can be expected when the depth of the structure (9m) is 1.5 times the wave height (4.5m). The Sainflou method of wave pressure theory describes the forces acting on the wall.

ADVANTAGES Flexibility Low transmission and reflection DISADVANTAGES Large volume of material needed Large area of seabed ocupation

p 1 = (p 2 + w0 h)

OPTION B: VERTICAL BREAKWATER DESCRIPTION

p1

Traditionally constructed from interlocking stone blocks, the technology has since improved. Now concrete caissons are used.

WAVE ACTION

H + h0 H + h + h0 SEA p1

H +h 0

H h0

SWL

h

pz p2

DISADVANTAGES Wave reflection and transmission Undermining and erosion

BREAKING WAVES FORCES ON VERTICAL WALLS It is expected that breaking waves will also act on the structure. As some areas are below 1.5 times deeper than the wave height. In addition sediment collecting in the breakwater will lower the depth over time. The force of these waves are calculated with the Minikin formula.

OPTION C: COMPOSITE BREAKWATER DESCRIPTION WAVE ACTION

Rubblemounds are placed infront of the upright sections of breakwater. These blocks dissipate energy before reaching the upright wall.

p d = 101w pd Hb LD D,d d D

ADVANTAGES Increased strength over vertical breakwater DISADVANTAGES Large seabed area Less suitable for deep water conditions

Hb

hd

LD

D

(D + d d )

= maximum dynamic pressure = breaker height = wave length = depth at the toe of the wall = depth one wave length infornt of the wall

AREA OF BREAKWATER

OPTION D: PILED BREAKWATER DESCRIPTION WAVE ACTION

Piled breakwaters are constructed in the form of sheet piles anchored to each other with the space between them filled with infill. ADVANTAGES Good in poor soil conditions Work carried out above sea level Cost effective DISADVANTAGES Must use multiple walls for extra strength

SELECTION CRITERIA

OPTION 1

EASE OF LAYOUT

2

SENSITIVE TO ENVIRONMENTAL CONDITIONS

3

HABITATABLE UTILIZATION CONDITIONS

4

EASE OF AVAILABILITY OF MATERIALS/EQUIPMENT

5

LOW COST OF CONSTRUCTION

6

LOW COST OF MAINTANCE

A

B

C

D

CONCLUSION Tsinker, Gregory P. Port Engineering: Planning, Construction, Maintenance, and Security. John Wiley & Sons. New Jersey. 2004.

THE GRAND TOUR OF EUtopia

The sheet pile breakwater provides the ideal breakwater typology for the masterplan. Its low environmental impact, strength, and ease of installation suit the site’s environmental sensitivity, and the short window of installation between inclement weather.

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# The Grand Tour of EUtopia. Design Realisation

Relocating across memory to critique the contemporary European Union. The Grand Tour of EUtopia is a modern pilgrimage critiquing the role o...

# The Grand Tour of EUtopia. Design Realisation

Relocating across memory to critique the contemporary European Union. The Grand Tour of EUtopia is a modern pilgrimage critiquing the role o...