• Journal of the Korean GEO-environmental Society
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• v.16 no.3
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• pp.5-13
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• 2015

Wave overflow can cause a failure of sea dike structure. Based on the results of the field surveys on mound-type sea dike, the failure of vicinity of crown and the scouring of toe at the landward was revealed as the most representative failure example. One of the main factors related to this failure pattern is overflow-induced pressure and velocity. Thus, in this study the analytical equations which can determine the pressure and the velocity induced by overflow in sea dike were proposed and verified. To accomplish this, assumed that the flow is quasi-steady and irrotational, and concentric circular streamlines around the vicinity of crown and toe of the sea dike. Flow was assumed as critical state and Bernoulli equation was used to develop the equations that can determine the pressure and velocity at the vicinity of crown and toe of the sea dike. Using these equations, the pressure and the velocity were calculated in condition of various overflow depths and radiuses of circular streamline. Based on the calculation results, while a negative pressure was occurred at the vicinity of crown, a significant amount of positive pressure occurred at the toe. The existence of flow-induced shear stresses was also confirmed. In addition, the limitation of the proposed equations was discussed.