Structural Integrity Management (SIM) processes are usually adopted in offshore engineering practice to monitor the effects of ageing on existing platforms, evaluating the opportunity for their service life extension. Updated analysis and verification of critical structural components reliability are periodically carried out following the State Of the Art Practice (SOAP), making reference to up to date International Standards.
Verification and updating of the input data for design with particular reference to environmental loads and soil/structural properties need to be considered as fundamental steps in the SIM process. In fact, design loads may vary due to equipment modifications and/or new assessments carried out according to SOAP and updated International Standards regarding meteocean, geotechnical and seismic data. Due to the above, new structural and geotechnical investigations or simply a reinterpretation of available design data need to be considered as mandatory.
This paper is aimed at describing the structural re-assessment of existing platforms in the Adriatic Sea (Italy) carried out by following the SIM methodology in line with the design procedures recently developed for new installations, focusing the attention on the foundation system subjected to earthquake loads in the presence of liquefiable soil conditions.
An applicative example will be presented to show how an updated geotechnical interpretation of soil data combined with advanced calculation methods can help to avoid unnecessary and expensive foundation solutions.
