Analysis of jack-up units using a Constrained NewWave methodology

There is a steadily increasing demand for the use of jack-up units in deepe r water and harsher environments. Confidence in their use in these environm ents requires jack-Lip analysis techniques to reflect accurately the physic al processes occurring. This paper is concerned with the models appropriate for the dynamic assessment of jack-ups, with a balanced approach taken in considering the non-linearities in the structure, foundations and wave load ing. A work hardening plasticity model for spud-cans on sand is used for th e foundation model. The spectral content of wave loading is considered usin g NewWave theory, and the importance of random wave histories shown by cons training the deterministic NewWaves into a completely random background. A method for determining short-term extreme response statistics for a sea-sta te using Constrained NewWaves is detailed. (C) 2001 Elsevier Science Ltd. A ll rights reserved.