Mumbai University > Civil Engineering > Sem 5 > Transportation Engineering 1

Marks: 4M

Year: May 2015

Breakwater:

The protective structure constructed to enclose the harbor and to keep the harbors waters undistributed from the force of wind generated and from the effect of heavy and strong seas are termed as breakwaters.

Function of breakwater:

A breakwater structure reflect & dissipate the strong sea waves & makes it possible to use the area enclosed as a safe anchorage for ship & to facilitate loading of cargo in calm waters. Offshore breakwaters also called as bulkhead, reduce the intensity of wave action I inshore waters and thereby reduce coastal erosion or provide safe harborage.

Breakwaters are two types:-

1. Vertical breakwater
2. Rubble mound breakwater

Vertical wall breakwater:

Vertical wall breakwater should be constructed under following three conditions

• Sea bed should be resistant to corrosion
• Foundations should not be subjected to uneven settlement or differential settlement
• Depth of water should be sufficiently great so as to prevent the breaking of waves i.e. vertical wall breakwater should not be constructed in a depth of water less than twice the greatest storm wave.

Rubble mound breakwater:-

• A rubble mound breakwater of a central portion termed as core and protective layer termed as armour.
• Core is small pieces of stone and quarry run. Armour layer is very important layer. Hence graded stones should be provided in between the core and the armour layer for better dissipation of energy and for protecting the finer core material from being sucked out on the return wave