The challenge of numerically implementing numerous force–resultant models in the stability analysis of long on-bottom pipelines

✍ Scribed by Yinghui Tian; Mark J. Cassidy

• Publisher: Elsevier Science
• Year: 2010
• Tongue: English
• Weight: 1001 KB
• Volume: 37
• Category: Article
• ISSN: 0266-352X
• DOI: 10.1016/j.compgeo.2009.09.004

✦ Synopsis

Plasticity models written directly in terms of force and displacement are finding increased popularity in describing the behaviour of offshore foundations. However, when applied to the on-bottom stability analysis of pipelines under random storm loading, hundreds, if not thousands, of models must be incorporated with structural elements in a three-dimensional analysis and simultaneously solved. This necessitates extremely efficient and accurate numerical integration techniques. This paper scrutinizes constitutive integration algorithms within both explicit and implicit frameworks, and applies them to a two-surface mixed hardening model that describes the force-displacement behaviour of a pipe partially embedded in sand. Detailed solutions are provided, allowing implementation of the pipe-soil model into any standard structural finite-element program. Through use of practical examples, the efficiency and accuracy of the solution methods are assessed.