A method for estimating strength and reliability of stiffened plates for pontoon-type VLFS

This paper deals with a simplified method for estimating strength and reliability of stiffened plates for pontoon-type very large floating structures (VLFS), which are supposed floating airport, as a part of studies on reliability based preliminary design systems. Firstly, limit state conditions are shortly presented for the buckling and ultimate collapse strength of stiffened plates under combined compression, shear and lateral pressure in the deck, bulkhead and bottom parts of VLFS, especially, by using a simplified estimation formula. Next, the validity is shown by nonlinear finite element method. Finally, the reliability level is investigated through numerical examples for a 5,000 m-class VLFS under a trial design.