Structural performance of buried pipeline undergoing fault rupture in sand using Taguchi design of experiments

Abstract

Nonlinear structural response of buried continuous steel pipeline undergoing fault rupture deformation is studied in a systematic manner. A detailed and efficient analysis framework for design is proposed and explained with a case study. A three-dimensional nonlinear finite element (FE) model previously developed and validated by the authors is used for this study. Taguchi method for design of experiments is employed to evaluate the structural performance of buried pipeline. It is also used to identify the influence of different parameters such as, the fault crossing angle, faulting type, the operating conditions of the pipeline, geometry of the pipe cross-section and material properties of the pipe and soil on the structural behavior of buried pipelines. The proposed method can be successfully employed to derive peak strain demands as a function of fault displacements for a given set of input conditions in an efficient manner leading to an efficient and safe design solution to this problem. A case study involving NPS 24 steel pipeline with a maximum operating internal pressure of 9.1 MPa is also carried out. The method presented here is suitable for pipeline strain hazard analysis, applicable for major oil and gas transmission lines crossing seismically active faults. • An efficient design approach for oil and gas transmission pipelines crossing active faults is presented. • Only 18 analysis are carried out instead of a full factorial design of total 2916 possible combinations. • Overall, the analysis methodology will be useful in performing strain hazard analysis of pipeline fault crossings.