Berm breakwaters, fifteen years experience

Berm breakwaters have been designed and constructed in Iceland since 1983. Over twenty nibble mound structures of the berm type have been constructed so far, fourteen were new structures, whereas the remaining six were improvements or repairs of existing breakwaters. During 1998 two berm breakwaters are being extended Further two structures will be built every year for the next 2-3 years. Although some of the berm structures in Iceland hale already experienced the design or near to design wave conditions, only minor profile changes have been observed. Valuable experience has, however, been learned from the inspection of the reshaped profile of one structure. The initial idea of berm breakwaters was that they should be wide voluminous structures, built of two stone classes with a wide size gradation. The Icelandic type of berm breakwaters has however been developed into a less voluminous, more stable structure, where large emphasis is put on maximising the outcome of the armour stone quarry and utilising this to the benefit to the design.