A Consideration on Safe and Efficient Operation of Offshore Structures Using Ocean Wave Information Facing Open Seas

Abstract

During the maintenance and construction of offshore structures, it is necessary to ensure calmness in terms of safety and workability in the relevant sea area. In this study, we statistically analyzed the observation data of GPS wave gauges in open seas from the Japanese wave information network (Nationwide Ocean Wave information network for Ports and HArborS: NOWPHAS), and clarified the occurrence of missing data and the number of consecutive days of calm conditions. Based on this, the number of calm conditions that last for three consecutive days or more, which is defined as the minimum required for construction, occurs only two to three times per month. For this reason, it became clear that the maintenance and construction of offshore structures are extremely difficult. Finally, the correlation analysis is conducted to know the relation among the occurrence of missing data, the number of consecutive days of calm conditions, and the statistical values of wave heights.