Abstract: (26035 Views)
Determination of allowable free span length plays a crucial role in design of offshore
pipelines. The seabed intervention cost and safety of an offshore pipelines project are largely
influenced by pipelines free spanning during the project life time. Different criteria are proposed by
both the current designing guidelines and researchers there is however lack of comprehensive
assessment of independent parameters affects the design length of free span. In this note, it is
intended to investigate the effects of seabed formation along with axial force on Natural Frequency
of offshore pipelines. Based on this assessment a new simple formula is proposed. Finally, to
evaluate the result of this study, the allowable free span length of Qeshem Island pipelines is
calculated as a case study and compared with those of the DNV (1998) and ABS (2001) guidelines
and the modal analysis.
Type of Study:
Technical Note |