연안역 해저구조물의 안전에 관한 연구

A Study on the Safety of Sea Bed Structures in Coastal Area

연안해역에 산업시설 및 생활기반시설이 집중됨에 따라 연안해역에는 선박교통량이 폭주하게 되었으며, 또한 송수관, 송유관, 가스파이프 라인 및 케이블 등 해저구조물의 건설이 증가하게 되었다. 해저침식에 의한 구조물의 노출, 닻의 투하에 의한 구조물의 충격 등 해저구조물이 손상을 받으면 막대한 인명 및 재산피해를 초래할 수가 있다. 따라서 이 연구는 조류에 의한 해저의 침식, 닻에 의한 해저충격력, 닻의 파주깊이를 현장자료 등에 기초하여 해저구조물의 안전성을 평가한 것이다.

In coastal area, there are various flows such as tidal currents, wind-induced currents, nearshore currents and so on, and also there is heavy traffic due to the numerous sailing vessels. The flows in coastal area bring in topographical changes through the accumulation/erosion on the sea bed. Topographical changes on the sea bed affect the safety of vessels and sea bed structures because those make change of water depth and buried depth. Buried depth is one of major factors to define the striking force of anchor to sea bed structure. When ship's anchor is dropped to the sea bed, the anchor strikes the sea bed and penetrates sea bed to the certain depth. In this case, sometimes structures on/under the sea bed may be damaged by strike or touch of anchor. This study presents the qualitative method to predict the topographical changes by flows, and some approximate equations which calculate the striking force and the penetrating depth of anchor. This method and equations are applied to the Inchon bay to evaluate the safety of gas pipe buried in sea bed. In results of the study, the sea bed gas pipe is safe from strike and penetrating depth of anchor, but continuous observation and caution is required because the erosion occurs in some places around the buried gas pipe. The results of this study are expected to be used as the design parameters of sea bed structures.