5. Conclusions and suggestions
Based on the experimental observations and the analysis above, it can be concluded that the failure of the oil pipeline should be originated from the liquid impingement erosion induced by falling raindrop. Thus, suggestions to prevent the recurrent of the accident may include: (1) Adding water-proof coating or cover to avoid the direct exposure of the external surface of the pipeline, which may be also beneficial for averting other types of erosion and corrosion; (2) keeping the underground trench always dry; (3) periodically checking the covered cement boards, and ensuring no locally large holes. The present work provides sufficient experimental evidences for liquid impingement erosion, which may be helpful for future engineering failure analysis.
