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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