SOLITARY WAVE INTERACTION WITH VERTICAL POROUS BARRIERS

Tsunami waves pose a threat to the coastal zone and numerous studies have been carried out in the past to understand them. The present study-carried out in the 2D wave flume at the Ocean Engineering Laboratory of IIT Bombay-focusses on the interaction and run-up of solitary waves on coastal protection structures in the form of thin, rigid vertical porous barriers with special attention given to the degree of energy dissipation. In order to understand the physics of the energy dissipation problem, the propagation of the solitary wave and its interaction with the porous barrier has been studied from the viewpoint of energy balance. Based on this, a proper relationship for the wave energy dissipated by the barrier has been developed. Using this relationship, the experimental data has been analyzed and we have determined that the plate porosity that gives the optimal energy dissipation characteristics lies within the 10-20% range. In addition, using the experimental data, we have derived a formula for calculating the maximum wave run-up on the porous barrier models which should be useful in the planning, design, construction and maintenance of coastal protection structures.