Wave Action on Coastal Structures

7/24/2019 Wave Action on Coastal Structures

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Wave action on Coastal

Structures


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Sea Walls

A structure separating land and water areas. It is

designed to prevent coastal erosion and other damage

due to wave action and storm surge, such as fooding.

Seawalls are normally very massive structures because

they are designed to resist the ull orce o waves and

storm surge. In practice, seawalls and revetments are

synonyms.


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A seawall is constructed at the coastline, at the oot o

possible clis or dunes.

A seawall is typically a sloping concrete structure it can

be smooth, stepped!aced or curved!aced.

A seawall can also be built as a rubble!mound structure,

as a bloc" seawall, steel or wooden structure.

#he common characteristic is that the structure is

designed to withstand severe wave action and storm

surge.


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A rubble!mound revetment oten protects the oot o such

non!fe$ible seawalls.

A rubble!mound seawall bears a great similarity to a rubble!

mound revetment however a revetment is oten used as a

supplement to a seawall or as a stand!alone structure at

less e$posed locations.

An e$posed di"e, which has been strengthened to resist

wave action, is sometimes reerred to as a seawall.


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%ertical Sea Walls

%ertical seawalls are built in particularly e$posed

situations. #hese refect wave energy.

&nder storm conditions a non!brea"ing standing wave

pattern can orm, resulting in a stationary clapoticwave

which moves up and down but does not travel hori(ontally.

#hese waves promote erosion at the toe o the wall and

can cause severe damage to the sea wall. In some cases piles are placed in ront o the wall to lessen

wave energy slightly.
https://en.wikipedia.org/wiki/Standing_wavehttps://en.wikipedia.org/wiki/Clapotichttps://en.wikipedia.org/wiki/Clapotichttps://en.wikipedia.org/wiki/Standing_wave


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%ertical Sea Wall

Adv. #he )rst implemented, most easily

designed and constructed type oseawall.

%ertical sea walls defect wave energyaway rom the coast.

*oose rubble can absorb wave energy.

+is Adv. #hese are partial to a lot o e$pensive

damage in a short period o time.

%ertical design can be undercut by high!wave energy environments over a long

period o time.


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Curved Stepped Sea Walls

Curved or stepped seawalls are designed toenable waves to brea" to dissipate wave energyand to repel waves bac" to the sea.

#he curve can also prevent the wave overtoppingthe wall and provides additional protection or thetoe o the wall.


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Curved Stepped Sea Wall

Adv. Concave structure introduces a

dissipative element.

#he curve can prevent waves romovertopping the wall and provides e$traprotection or the toe o the wall

+is Adv. -ore comple$ engineering and

design process.

#he defected waves can scourmaterial at the base o the wallcausing them to becomeundermined.


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-ound #ype Sea Wall

-ound type seawalls, using revetmentsor riprap, are used

in less demanding settings where lower energy errosional

processes operate.

#he least e$posed sites involve the lowest!cost bul"heads

and revetments o sand bags or geote$tiles.

#hese serve to armour the shore and minimise erosion and

may be either watertight or porous, which allows water to

)lter through ater the wave energy has been dissipated.
https://en.wikipedia.org/wiki/Revetmenthttps://en.wikipedia.org/wiki/Ripraphttps://en.wikipedia.org/wiki/Geotextileshttps://en.wikipedia.org/wiki/Geotextileshttps://en.wikipedia.org/wiki/Ripraphttps://en.wikipedia.org/wiki/Revetment


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-ound #ype Sea Wall

Adv. Current designs use porous designs o

roc", concrete armour.

Slope and loose material ensurema$imum dissipation o wave energy.

*ower cost option.

+is Adv.

*ess durable.

Shorter lie e$pectancy.

Cannot withstand or protect rom

high!energy conditions eectively.


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Wave Action on Coastal Structures