New proposal of evaluation method for cargo handling efficiency on mega float container terminal facility

摘要

The Japanese government is developing its logistical capacity of international hub port in order to improve Japan's global economic competitiveness. One of the most important issues is to develop international container terminal network. However, since it is expected that coming aging society would give some limitation to spending share for the projects which are strongly required, the reduction of construction cost is urgent task. Inland sea area, which is often characterized by deep soft-ground and deep sea, generally tends to be preferred as container terminal site, because its calm oceanographic condition could guarantee cargo-handling efficiency on container terminal, however we often find that deep soft-ground and deep of inland sea become significant obstacles to realize the projects, because they are cost spending factors in the construction. Although construction engineering is highly improved for conventional facility i.e. the facility with fixed type structure, an application of floating type structure could be a useful substitute to reduce the construction cost due the removal of expensive foundation. Instead, container terminal as well as vessel are always subjected to sea wave motion, so that successful application of floating type structure needs to assure its cargo-handling efficiency, which is preferably more than or equal to that of conventional facility. The authors proposed a method to evaluate cargo-handling efficiency, including the operationality of the crane, in relative oscillation between vessel and MFCT, i.e. mega float container terminal meaning floating type container terminal. The proposal was based on the extensive utilization of the existing criteria, i.e. allowable oscillations of vessel and related facility, which guarantee approximately 100% cargo-handling efficiency and comfortable operationality on fixed type quay wall. Computing simulation showed that the influence of the cargo motion due to the terminal oscillation was significantly small enough to sustain cargo-handling efficiency. Moreover the operationality represented by the dwelling comfortability in operation room was also investigated by comparative study between the obtained simulation results and the related standards.