Stress and displacement analysis of aerial oil & gas pipelines: A case study of Lantsang tunnel crossing project

Lantsang tunnel crossing project involves three parallel pipelines of gas,crude oil and refined oil. due to the complex condition of lagging in the tunnel,the characteristics of steep slope tunnel and the fact that the project is located at earthquake fault zone,it is of great significance to ensure the safety of operation. therefore,stress and displacement analysis are required on the three pipelines. based on beam element and finite element analysis,caesar ii software was used to establish stress analytical model for the pipelines in yanyingshan tunnel. stress and displacement analysis of the three parallel pipelines under normal condition were conducted. the following conclusions were drawn: (1) after comprehensive consideration of the stress distribution of the three pipelines,it was determined that bend 1 and bend 2 were the most risky sections in yanyingshan tunnel pipelines; (2) the displacement of high pressure pipeline should be particularly monitored during engineering project; (3) axial displacement is the key of displacement validation of pipelines penetrating the tunnel.