Buckling behaviour analysis of a buried steel pipeline in rock stratum impacted by a rockfall

• Buckling behaviour of buried pipeline impacted by a rockfall was simulated.
• Pipeline's cross section becomes from oval to peach shape under bigger impact force.
• Impact dent, stress area and plastic strain increase with the impact force increases.
• Buckling of buried pipeline after second impact is more serious than first impact.

Rockfall impacts have seriously threatened the operations of buried pipelines in geologically unstable regions. In this paper, the buckling behaviour of a buried pipeline impacted by a cube-shaped rockfall was simulated. Effects of the impact velocity, buried depth, impact position, rock height and base area on the stress and plastic strain of the buried pipeline were discussed. The buckling behaviour of a buried pipeline due to continuous impact was also studied. The results show that the cross-section of the buried pipeline evolves from an oval to a peach shape as the impact velocity increases. As the buried depth decreases, the length and depth of the impact dent, the high stress area and the plastic strain increase. However, they increase as the impact velocity, rock height and bottom area increase. The plastic strain distribution of the buried pipeline is more uneven for an eccentric impact. Buckling of the buried pipeline after the second impact is more serious than that after the first impact. After the second impact, the maximum plastic strain appears on both sides, not at the centre line of the impact dent.