Transverse seismic response analysis of offshore pipelines in proximity to the sea‐bed

Abstract

Abstract Both harmonic and seismic responses of several idealized offshore oil pipelines in proximity to the sea‐bed have been studied in this paper by using a digital computer algorithm. In this, spatial discretization was based on finite elements, with nodal lumped masses, while a step‐by‐step explicit forward integration scheme was implemented for processing in the time domain. A study of the basic system parameters shows that pipe response to a horizontal transverse ground excitation is mainly affected by the clearance between the pipe and the sea‐bed, pipe geometry and its end‐restraints. Results also show that the overall effect of non‐linear pressure drag is not substantial. Relevant fluid dynamic aspects affecting system response as well as possible effects of marine growth on pipe surface and structural/chemical degradation of the pipe coating are also discussed.