Research on Damage Assessment of Buried Standard and Carbon-Fibre-Reinforced Polymer Petroleum Pipeline Subjected to Shallow Buried Blast Loading in Soil

Buried petroleum pipelines may encounter threats from blast loading due to terrorist attacks, accidental explosions, and artificial blasting during in-progress construction. Carbon-fibre-reinforced polymer (CFRP) is often used for the repair and reinforcement of buried petroleum pipelines. It is meaningful and necessary to distinguish the different responses and establish an effective damage assessment method for standard petroleum pipelines and CFRP-supported petroleum pipelines buried in soil under blast loading. In this study, under fixed end constraints, experimental analysis and numerical simulations were combined to assess the damage of a standard petroleum pipeline and a CFRP petroleum pipeline buried in soil under blast loading. The results showed that, for a scaled distance of 0.19 m/kg1/3, plastic deformation occurred on the surfaces of the two pipelines facing the explosive. The antiexplosion performance of the CFRP pipeline was better than that of the standard pipeline, and the CFRP sheets had a positive effect on the protection of the buried petroleum pipeline during the buried blast loading. Furthermore, based on pressure-impulse damage theory and with consideration of the feasibility under real circumstances, two pressure-impulse damage evaluation curves for standard and CFRP pipelines facing explosive loads were established separately based on a new critical ratio of the dent depth and length. Finally, based on the two pressure-impulse damage evaluation curves and the new critical ratio, two pressure-impulse damage criteria for these two buried petroleum pipelines were defined. Moreover, with the two pressure-impulse damage evaluation curves, mathematical formulae for the two different buried petroleum pipelines were established to generate pressure-impulse diagrams. With the established formulae, the damage to the standard buried pipeline and the CFRP pipeline could be evaluated effectively. Damage to other similar standard pipelines or CFRP pipelines buried in soil with different design parameters due to shallow buried blast loading could also be evaluated using this method.