Structural analysis of a submarine pipeline subjected to underwater shock

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