Dynamic Response of Buried Parallel Gas Pipeline Under the Explosion Impact

Natural gas leakage and explosion have become the main extreme disasters of buried gas pipelines. TNT equivalent method is selected as the estimation model for small hole leakage explosion of gas pipeline. The material constitutive model is appropriately selected. Arbitrary Lagrange-Euler method (ALE) is used to verify the accuracy of the model. A three-dimensional solid model of buried gas pipeline-soil-explosive coupling is established. The relationship between dynamic response (equivalent stress, displacement) of buried gas pipeline and explosion center distance and explosive quantity is analyzed. The results show that the ALE method can well describe the propagation law of spherical explosion waves in the soil, and can visually show the macro-evolution process of the explosion cavity and the surface mound. Under the explosion center distance of 205 cm, the stress increases with the explosive charge. The anti-explosion limit charge of the pipe body is 58.4 kg. Both the stress and displacement increase with the explosive charge or the decrease of the explosion center distance. The <i>X</i>-direction displacement, the <i>Y</i>-direction displacement of front explosion point and rear explosion point increases first and then decreases with time. The <i>Y</i>-direction displacement of the top of the pipe presents a second shock that increases first and then decreases. The displacement of the bottom of the pipe changes approximately sinusoidally. There is a deviation between the strain-based and stress-based failure evaluation results. The strain-based results are relatively conservative. The study can provide a reference for the safety assessment of parallel gas pipelines.