Experimental study on local scour around vertical breakwater by tsunami waves

A set of 2D laboratory experiments was designed for alluvial bed to investigate local scour around vertical breakwater by tsunami waves. Processes of wave uprush and back wash, change of cross-shore beach profile and scour were measured and recorded. The FLOW3D software was validated through available laboratory experiments to numerically simulate the flow field. The results showed that the beach was significantly protected by vertical breakwater. Meanwhile, local scour was appeared around vertical breakwater. The uprush wave that accompanied the vortex near the toe had a scouring effect on onshore beach around vertical breakwater. The hydraulic drop that generated back wash wave through the breakwater had a scouring effect on offshore beach around vertical breakwater. The maximum local scour depth could decrease, with increase of vertical breakwater height.