Structural analysis of a submarine pipeline subjected to underwater shock

This paper presents a computational approach to safety assessment of submer ged pipelines, exposed to underwater shock. The fluid-structure interaction between the seawater and pipeline are handled using the coupled finite-ele ment and boundary-element codes, based on the Doubly Asymptotic Approximati on (DAA). The shock pressure transmitted from the seawater and sea bottom i s calculated based on published empirical equations, which are incorporated into the coupled fluid-structure codes. Four cases of pipeline configurati ons were modeled and simulated, in this study. The first case is a submerge d empty pipeline without any cover, the second case is a submerged empty pi peline with concrete cover, the third case is an empty pipeline buried in s and and the fourth case deals with a fluid-filled pipeline buried in sand. A comparison between the four pipeline configurations is made, and the effe cts of the concrete cover and sand for the protection of the pipeline are e xamined. (C) 2000 Elsevier Science Ltd. All rights reserved.