Wave attenuation characteristics of single row of perforated hollow piles in laboratory

Laboratory investigation on perforated hollow piles in a single row was con ducted in a two dimensional regular wave flume to study the performance of such an arrangement in dissipating wave energy. The influence of splicing b etween the piles, size of perforations, different percentage of perforation s and water depth on wave attenuation has been investigated. It is found th at water depth has insignificant effect on transmission coefficient (K-t) a t higher wave steepness. K-t decreases as the relative clear spacing of pil es (b/D) decreases and also it decreases as the incident wave steepness inc reases. At lower value of b/D, K-t decreases with increase in percentage of perforations. For the same percentage of perforations, the pile groups wit h larger size of perforations transmit more wave energy than pile groups wi th smaller size of perforations. The perforated hollow pile breakwater is a n alternative solution to protect the coast from erosion where the erosion is due to wave energy concentration or onshore offshore movement of sand.