1. Click to edit Master title style
1
GROUP 5 :
Aarthi.V(310620103001)
Abdul Rahman M(310620103002)
Jebanandh Paul J(310620103012)
Jyothilakshmi P.S (310620103015)
Kiran Chakkaravarthy K(310620103017)
TYPES OF
BREAKWATERS
191CEE704T :AIRPORT AND HARBOUR ENGINEERING
2. Click to edit Master title style
2 2
INTRODUCTION
• Breakwater is the artificial protective barrier constructed to enclose harbours and to keep the
harbour waters undisturbed by the effect of heavy and strong sea waves.
• Breakwater enables the use of the enclosed area as a safe anchorage for ships and facilitates
cargo loading in comparatively calm waters.
3. Click to edit Master title style
3
FACTORS CONSIDERED FOR CONSTRUCTING BREAKWATER
1.Alignment : straight converging arms where angle of intersection <60 degrees
2.Information : Character of coastal currents , cost and availability of materials, directions and force of prevailing
winds , nature of foundation , height of waves
3.Consideration :
• Design should be on extreme phenomena and not on mean/ average
• Height of wave = 0.34 (F)0.5
4. Forces acting on breakwater :
• Hydrostatic forces
• External forces: wind and wave action produces vibrations in the masonry structure and weakens the
different courses of masonry.
• Dynamic force or wave effect will not be nil at the base of mound as depth of water is less than half wave
length. The waves existing in such conditions will be shallow water waves.
3
4. Click to edit Master title style
4
CLASSIFICATION OF BREAKWATERS
1.Heap or mound breakwater : Heterogeneous assemblage of natural rubble/ stone blocks with no binder
Rubble mound breakwater :
• Armours: irregular heavy stones layer constructed with large voids to hold water
• Secondary armours: smaller size stone to dissipate energy
• Core : layers of mounted stones from quarry waste
4
5. Click to edit Master title style
5
• Rubble mound breakwater supplemented by patented stones :
• Concrete blocks having rectangular section where energy dissipation is not even.
• Hence concrete blocks which are hydraulically rough and stable in their positions are developed:
• Tetrapods : 4 legged truncated cones with reinforcement (40-250kN) , dissipates more energy from waves. Legs of adjacent units on
sides and on top get interlocked.
• Tribars : three legged connected with plate at mid height get interlocked and remain stable.
• Modified cube : cube shaped with grove to interlock adjacent units and resist incoming waves impact.
• Dolos: combines two anchors to form a single dolos.
5
6. Click to edit Master title style
6
2. MOUND WITH SUPERSTRUCTURE BREAKWATER :
• Mound construction with top part made solid adopted between LWL and HWL
• A solid superstructure that consists of a Quay protected by a parapet on the sea face is constructed on top of the
rubble mound. Such a construction is founded on the low water level.
The advantages of such a construction are:
1. It gives a platform for handling cargo.
2. It protects the top of the mound.
3. It decreases the mass of rubble required for the mound in proportion to the depth at which it is founded.
6
7. Click to edit Master title style
7
3. UPRIGHT WALL BREAKWATER:
• A wall or upright breakwater as big regular wall raised to construct a harbour basin on solid natural and
artificial foundation to resist the forces and their components generated by incoming water and waves .
ADVANTAGES :
• Reduce the amount of material
• Less width foundation
• Avoids dangers of unequal settlement
• Increases size of harbour basin
DISADVANTAGES :
• Greater height for wall under water
• Cost of construction is high
• It requires sinking for foundation
7
8. Click to edit Master title style
8
4. SPECIAL BREAKWATERS:
• Breakwater resisting wave forces in first 5 m to 10 m depth with solid construction .
• Types :
• Floating : well connected floating bulk heads5-10 m deep anchored below 10 m
• Hydraulic : A hydraulic or water-jet breakwater is formed by- forcing water through a series of nozzles mounted on
a pipe which is installed perpendicular to the direction of the incident waves. The jets create a surface current which
results in breaking of the incident wave.
• Pneumatic : range of waves with lower height can be achievedThe structure utilizes an air bubble column
deep in water to induce a counter flow which opposes the wave-current resulting in damping of its
energy and the height of the wave
8
PNEUMATIC BREAKWATER HYDRAULIC BREAKWATER FLOATING BREAKWATER
9. Click to edit Master title style
9
CONCLUSION :
• Breakwaters shield the shoreline from strong wave
action. It does this by lowering the tidal energy as it
hits the structure and gets reflected off. It provides an
artificial shelter for the harbour’s infrastructure and
vessels.
• Building a breakwater along the shoreline is a decrease
in sediment transport. The amount of coastal transport
in the shielded seas is slowed because the energy of
the waves that move sediment drops drastically in the
breakwater shadows. As a result, there is a greater
deposit of sediments.
• Breakwaters make the sea calm enough to permit the
safe use of harbour amenities and marine operations
and shelter for small boats.
9
RUBBLEMOUND BREAKWATER-
CHENNAI PORT
10. Click to edit Master title style
10
REFERENCES :
BOOK: Harbour ,dock and tunnel engineering – R SRINIVASAN
https://icce-ojs-tamu.tdl.org/icce/article/view/2052
https://www.britannica.com/technology/breakwater
https://www.sciencedirect.com/topics/earth-and-planetary-sciences/breakwater
https://theconstructor.org/water-resources/mound-breakwater-types-construction-
and-protection/559854/
10
