Influences of sea-dike crown walls on the undertow during storms

Abstract

   Crown walls as a measure against wave overtopping are commonly-used on low-crested coastal dikes in Viet Nam. The presence of these walls, however, might modify the wave, undertow characteristics and eventually affect the dike-toe scour during storms. In this paper modifying characteristics of the undertow due to the wall presence are investigated through a series of fix-bed flume model experiments. The results shown that the undertow values, the profile and its across-shore distribution of the undertow markedly deviates.