Buckling failure of a buried pipeline subjected to ground explosions.

Ground explosions are one of the threats to the structural integrities of buried pipelines. To investigate failure modes of buried pipelines subjected to ground explosions, numerical calculation models of buried pipelines in soil and rock layers were established. The stress, strain, plastic deformation and failure modes of the buried pipeline were investigated. The effects of the explosion magnitude, diameter-thickness ratio, burial depth, explosion height and explosion offset on the failure behaviour of the pipeline in the rock layer were studied. The results showed that the pipeline deformation process only lasted for 0.03 s. The high stress zone and plastic strain zone were present in the upper part of the pipeline, and a dent appears. A buried pipeline in a rock layer is more dangerous than that in a soil layer due to the reflection of the explosion wave in the rock layer. The deformation, plastic strain and total energy of the pipeline increase gradually in the rock layer with increasing explosion magnitudes or diameter-thickness ratios, but these indices decrease with the increased burial depths, explosion heights and explosion distances. Empirical formulas can be used to predict the strain and dent rates of the buried pipeline. These results can provide the theoretical basis and references for laying pipeline, as well as for their safety evaluations and maintenance, etc. [ABSTRACT FROM AUTHOR]