PERFORMANCE OF CONCRETE ARMOUR UNITS OF BREAKWATERS IN INDIA - A REVIEW

Most of the breakwaters of the major, intermediate and minor ports as well as fishing harbours in India are constructed as flexible rubblemound structures, armoured with quarry stones or artificial concrete armour units. Tetrapods, Dolosse and Cubes are common concrete armour units, which are to be used in double layer in the armour of the rubblemound structures. Development of deep water ports in India has necessitated the designs involving lesser costs. In this context, use of single layer armour units on steeper slopes is inevitable. Single layer armour units like Accropode and Core-loc have also been used for a few breakwaters. Tetrapods are more popular in India in comparison with other armour units. Rubblemound breakwaters constructed in India, using artificial concrete armour units have stood well against the fury of waves. However, there are few examples of damages to the breakwaters during the severe cyclonic wave conditions. The design aspects, site conditions, constraints, and the performance of artificial concrete units have been discussed in the paper. It is observed that selection of design wave condition, packing density, placing method, slope, and proper toe-berm are important aspects in the design and construction of rubblemound breakwaters with artificial concrete armour units.