ジャッキ・アップ・リグの強度特性に及ぼすレグの大たわみおよび海底地盤の塑性変形の影響

抄録

The jack-up rigs tend to sway by the lateral force of wave, current and wind and the relatively large deformations are expected to occur on legs but the effects of these large deformations to the structural strength characteristics has not been studied so deeply until now. In addition to the large deformations of legs, the sea bed behaves as elastic/plastic springs and the sea bed plastic deformation affects the leg deformation to become larger. Namely, their effects to structural characteristics are amplified each other. Recently, the classification society requests the builder to check these effects in case of design of the super jack-up rig for deeper water operation and the simplified strength analysis method in required to be established. In this paper, the new strength analysis method considering large deflection of legs is presented and its effects with combination of sea bed plastic deformation is discussed by the results of numerical calculations.