A refined nonlinear analytical method for buried pipelines crossing strike‐slip faults

Abstract

AbstractThis paper presents a novel nonlinear governing equation and solution procedure for analyzing a buried pipeline at an active strike‐slip fault crossing. The proposed method includes exact nonlinear axial and nonlinear transverse soil–pipe interaction terms, in addition to geometrical nonlinearity terms in the governing equation. The assumption of partitioning the pipeline into four segments with four governing equations based on the soil yield threshold is removed, and a unified governing equation is introduced. Compared with existing methods, the proposed method has a significantly extended application range with improved accuracy and provides the advantage of including the sliding of buried pipelines within soil, transverse soil spring plasticity, and improved large‐deformation effects including the sliding effect. The solution procedure is improved by removing the optimization steps and external calculations. The proposed method is verified by comparison to a verified finite element‐based model with various fault displacements and angles, and the results are in excellent quantitative and qualitative agreement with the numerical results, even for cases of large fault movement. Finally, criteria for assessing the ovalization damage of buried pipelines are proposed. The proposed method fulfills the missed part of literature, and it is valuable for (1) verification of the nonlinear FEM analysis; (2) fast, economic, and reliable stability analysis and design of buried pipelines; and (3) a strong tool for future developments of buried pipelines seismic design guidelines.