The response of a platform subjected to a strong ground motion is highly affected by the method of modelling, and special attention should be paid to such advanced analysis.
While the potential of dynamic inelastic analysis and performance based design of offshore platforms is recognised in earthquake design and assessment, they have inherent shortcomings. This paper discusses the critical issues and their effects on the obtained results in the application of inelastic dynamic analysis. Areas of possible developments that would render the method more applicable to the prediction of dynamic response, and new developments towards a fully adaptive performance based design are explored. These developments lead to dynamic analysis results that are closer than ever to the true inelastic time-history behavior of the structures.
It is concluded that there is great scope for improvements of this powerful technique that would increase confidence in its employment, and encourage its use during design as the primary tool for reliability assessment under seismic loads. The results from a sample project indicated that inelastic time history seismic analysis provides a more realistic assessment of structural behavior and strongly recommended to be implemented for the design and reliability assessment of the fixed offshore structure under extreme seismic event.