Study on wave overtopping and wave-structure interactions of sea dyke amoured with layers of tetrapod using a numerical wave flume model

Abstract

Sea dyke section Got-Gia Loc from K0+000 to K3+094, Cat Hai district, Hai Phong province was constructed of quarry stone; the crest level of the dyke is from 3.7 m to 4.5 m. Suffering high wave impact forces, slip failure usually occurs due to either the low crest level or small size of stones. Under the conditions of high tide and wind level 5 or 6, wave overtopping can cause instability and destroy dyke structure. Increasing crest level appears to be unfeasible and uneconomic solution due to either scarcity of material or space limitations (road and residential houses closeby the dyke). Therefore, it is necessary to find an effective solution to reduce wave-structure interactions and also to propose a reasonable dyke cross-section to ensure safety of the dyke in rainy season. The paper refers to study on simulating wave-structure interactions, especially simulating the flow through quarry stone layer and Tetrapod block using IH2-VOF (numerical wave flume), so as to propose location of Tetrapod; reasonable dyke cross sections to maximize the wave reduction efficiency and also to calculate overtopping discharge, propose and design structure of the landward slope of the sea dyke as well as overtopping water collection system.