A discussion of the target safety of very large floating structures

摘要

Technological Research Association of Mega float has been developing pontoon type Very Large Floating Structures (VLFS). This system consists of floater and moorings and if necessary breakwater is added to this system. The VLFS is expected to be used for public use such as an airport and so on. In such a case many passengers, crews and ground service persons, will stay on the VLFS. VLFS also support many facilities and properties. VLFS must be highly safe and this paper presents a discussion on target safety Risk analysis and scenarios of catastrophic failure of pontoon type VLFS are briefly reviewed. Safety levels of various activities in Japan are reviewed in historical context and Fatal Accidental Rate for the activities are calculated. Perception of risk of VLFS is discussed when it is provided for public use. Acceptable safeties realized in the equations proposed in the past are also discussed. A trial calculation is made assuming the VLFS is used an international airport.