상치콘크리트 형상에 따른 사석방파제 피복층의 안정성에 관한 연구

Abstract

The value of the coastal area is very high due to its abundant resources. This coastal area has been developed in various forms due to the development of science and technology. Particularly, for the development for the control of the coastal area, structures such as offshore breakwaters, groins, and rubble mound breakwater are mainly installed. In addition, it is essential to construct suburban facilities such as breakwaters when constructing harbors. From these, rubble mound breakwater are one of the oldest types of coastal and harbor structures, which are constructed in a relatively small bay and area with shallow water. As a result, many researches have been carried out for the stability and hydraulic characteristics of rubble mound breakwater which reflected in actual design. In this study, the design equations developed for the existing infinite slope condition are validated to evaluate the stability of the armor layer of rubble mound breakwater with cap-concrete form. In this study, hydraulic model experiment and numerical model simulation have been carried out to use as basic data for design of rubble mound breakwater. First, the damage cases of rubble mound breakwater have been analyzed and then shape characteristics of cross section using structure parameter for rubble mound breakwaters constructed in coastal and trade ports were analyzed. Next, numerical model simulation using CADMAS-SURF was carried out to examine the hydraulic characteristics(run-up/run-down velocity, over- topping) as incident wave condition as well as crest height change of rubble mound breakwater. Finally, hydraulic model experiment was conducted to examine the stability of rubble mound breakwater as incident wave condition as well as crest height change of rubble mound breakwater. The main results are summarized as follows: 1) As the results of damage case analysis of rubble mound breakwater, the stability of armor layer affected by the size of cap-concrete were identified. 2) As the results of numerical model simulation, overtopping rate was decreased and run-down velocity was increased as the CH/AH value increases. Thus, it was predicted that as the crest height of cap-concrete becomes higher, the armor layer stability becomes weaker. 3) From the results of hydraulic model experiment for armor layer stability, it was found that when the value of CH/AH was increased, the damage rate of armor layer was increased which is in a good agreement with the prediction results of numerical model simulation.