Introduction of the axial force terms to governing equation for buried pipeline subjected to strike-slip fault movements

In past studies, several simplification assumptions exist in analytical methodologies and the axial force effect is calculated through external formulations and applied as a constant value to parts of the partitioned governing equations. However, applicability range of them is limited and can lead to significant errors with increasing solution complexity. In this study, we establish an improved governing equation to analyze buried pipeline as a linear material subjected to active strike-slip faults. This approach includes geometrical nonlinearity effects and exact axial force terms of the pipeline inside governing equation, and requires no additional external calculations, which significantly increases application range and accuracy even in the case of large deformation. The proposed methodology is verified against finite element-based results with various faulting angles and displacement ranges. Results of the analytical methods are in good agreement with numerical results in both qualitative and quantitative aspects even for cases with large fault movements. •Axial soil-pipe interaction and axial forces of the buried pipeline are detailly applied inside the governing equation.•Geometrical nonlinearity (large deformation) effects are applied inside the governing equation.•Extended application area and accuracy of analytical methodology in buried pipeline analysis even in large movements.