design of breakwaters
DESCRIPTION
a case study of designing of a breakwater at Mediterranean by Egyptian professorTRANSCRIPT
Design of Breakwaters
BY Dr. Nagi M. Abdelhamid
Department of Irrigation and Hydraulics
Faculty of Engineering
Cairo University
2013
Purpose for construction Breakwater A breakwater is a structure made of natural
stone or concrete elements which gives
shelter to a shoreline, harbour, anchorage, or
basin from the direct impact of incoming
waves.
To provide a safe, suitable accommodation for
ship refuge, supplies and transfer of cargo.
Protected navigation channel
Prevent deposition in entrance channel
Prevent erosion inside the harbour
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Breakwater design
Port Said East Port
Breakwaters - Problem definition
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Breakwater design
Port Said Port
Breakwaters - Problem definition
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Breakwater design
Alexandria Port
Breakwaters - Problem definition
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Breakwater design
North Alsukhna Port
Breakwaters - Problem definition
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Breakwater design
Tartous Syria
Breakwaters - Problem definition
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Breakwater design
Shinas port Oman
Breakwaters - Problem definition
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Breakwater design
Marina at Beirut
Breakwaters - Problem definition
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Breakwater design
Port and Marina at Beirut
Breakwaters - Problem definition
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Breakwater design
Requirement: limit overtopping and transmission
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Breakwater design
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Requirements: acces (harbour workers, traffic, oil piping)
Breakwaters - Problem definition
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Breakwater design
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Requirements: quay facilities (access, warehouses, sheds)
Breakwaters - Problem definition
Durres Port (Albania)
Breakwaters - Problem definition
San Stefano Marina and Private beach 13 Dr. Nagi Abdelhamid
Breakwater design
Breakwater Types
1- Permenent breakwater Rubble Mound Breakwaters
Vertical Wall Breakwaters
Vertical composite type
2- Temporary breakwater Peneumatic and hydraulic breakwater
Floating Breakwaters
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Breakwater design
Permanent breakwater
Rubble mound and vertical breakwaters.
.
Rubble mound breakwater Vertical composite type
breakwater
Vertical type breakwater 15 Dr. Nagi Abdelhamid
Breakwater design
Rubble Mound Breakwater
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Breakwater design
A rubble mound breakwater normally
consists of a core of small size rock covered
with large [heavy] rocks or concrete
elements. This outer layer is called the
armour layer. An under-layer of rock is
provided between the core and the armour
layer.
Outside layer large enough to resist wave
action.
Inside layer small enough to prevent
removal of native fine material in between.
Rubble mound breakwater
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Breakwater design
Advantages of Rubble mound breakwater:
Failure of the armour layer is not sudden
but gradually;
It allows high energy dissipation due to its
slope and transmission through porous of
mound;
It can be used for weak soil;
Easy maintenance and construction;
Small wave reflection;
Minimum overtopping less than Vertical
Breakwater.
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Breakwater design
Rubble Mound Breakwater
breakwater types Advantages Disadvantages
Rubble mound breakwater
1- Suitable for irregular bottom 1- Required material increases rapidly with increased water depth
2-Suitable for weak soil (distributed load) 2- High maintenance cost
3- Progressive damage 3- Large base cuts into basin area
4- Low toe scour
5-Simpler construction
6-Simpler maintenance
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Breakwater design
Cross sections of the breakwater
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Breakwater design
Vertical Wall Breakwaters - Types
breakwaters with vertical
concrete block
breakwater types Advantages Disadvantages
vertical breakwater
1- Material savings 1-Requireds firm Soil
2-control water depth clearly defined
2- High Construction requirements
3-Repair difficult
breakwaters with vertical
R.C. Wall (caisson)
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Breakwater design
Composite Breakwaters
concrete superstructure founded on a rubble substructure.
composite breakwater
1- Suitable for deeper water with less firm soil
1- More Complicated construction
2- More Susceptible to breaking waves
The caisson ( or concrete blocks) is placed on a high
rubble foundation.
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Breakwater design
Vertical Wall Breakwaters - Types
TYPES (continued)
• Semi-circular caisson Well suited for shallow water
situations with intensive
wave breaking
Due to the dissipation of
energy both the wave forces
on the caisson and the wave
reflection are reduced
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Breakwater design
Vertical Wall Breakwaters - Types
• Perforated front wall
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Breakwater design
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Dieppe (France)
The front wall is perforated by
holes or slots with a wave
chamber behind.
Due to the dissipation of energy
both the wave forces on the
caisson and the wave reflection
are reduced