Numerical investigation of buckling resistance in buried wave-shaped steel pipes for fault crossing

Buried pipelines, as critical infrastructure for oil and gas transportation, are at significant risk of buckling failure induced by fault displacement in seismically active regions. This study investigates a wave-shaped Steel Pipe for Fault Crossing (SPF), aiming to enhance its buckling resistance under fault displacement through geometric optimization. A three-dimensional nonlinear finite element model incorporating soil–pipe interaction was developed using ABAQUS. The mechanical responses of SPF and conventional pipes (CP) under fault displacement were systematically compared. The effects of fault displacement magnitude, dip angle, fault type, and internal pressure were evaluated, along with different wave-pattern configurations. Results show that SPF effectively concentrates strain within the wave-shaped segments, significantly reducing deformation in the smooth pipe sections. Compared with CP, the SPF reduces the peak bending moment by 68% and shortens the moment distribution range by 29%, thereby mitigating local buckling caused by excessive compressive strain. The double-wave design further improves strain distribution by redistributing localized high strains through multi-wave synergy, resulting in a lower peak strain and a more uniform strain field. Moreover, internal pressure has a more significant impact on the compressive performance of SPF, while the influences of fault type and dip angle are relatively limited. This study provides theoretical support and engineering guidance for the seismic design optimization of fault-crossing buried pipelines. • A 3-D numerical model of wave-shaped SPF interacting with the surrounding soil is proposed. • An in-depth analysis is conducted on the mechanical response of SPF under fault displacement, with comparison to conventional pipe. • Different working conditions and wave structure configurations are systematically evaluated for their impact on SPF performance. • High internal pressure enhances SPF’s compressive performance, while fault types and dip angles have little effect. • Double-wave geometry reduces strain peaks and improves distribution uniformity.