Investigation of the safety of seawalls against scouring

Abstract

Scouring phenomena is one of the most important issues in Coastal Engineering. Constructing protective structures such as seawalls on the shoreline can cause scouring and the estimation of scouring depth in front of such structures is one of the important problems in the design of their foundations. In this paper, based on experimental data, the beach level changes and potential of scouring at different locations in front of the constructed seawalls and in the case of a natural coast without protective structures are estimated and compared, which can be useful in coastal engineering studies and design and management of coastal defense projects. The results predicted by the model are compared with the experimental data indicating the good accuracy of the proposed model. The results obtained from the present work clearly indicate that the construction of seawalls at the shoreline results in a reduction of the associated seaward sediment transport and bed profile evolution but increases the local scouring depth which may cause damage to such structures. Incorporating the nonlinear effect of wave and wave current interaction into the proposed model has resulted in an improvement in the prediction of sediment transport, bed level changes and scouring depth in front of seawalls. This, in turn, results in a more effective design of seawalls to increase their safety against scouring.