EXPLOSION IMPACT SIMULATION METHODS FOR PARALLEL PIPELINE LAYING IN THE SAME DITCH AFTER GAS LEAKAGE

The explosion impact after gas pipeline leakage can be simulated by Arbitrary Lagrange-Euler Algorithm (ALE), Blasting Cavity Theory (BC) and Smooth Particle Hydrodynamics - Finite Element Method (SPH-FEM), each method has its own characteristic. Using the experimental data of Defense Research Establishment Suffield of Canada, it is found that both ALE and SPH can describe the propagation characteristics of detonation waves in a soil well, and SPH-FEM can accurately reflect the compression, cracking and deformation of soil after an explosion. For parallel buried gas pipeline laying in one trench, three pipe-soil explosion models were design based on the mentioned three approaches above, and the same response of pipeline were obtained under the same operating conditions. However, the soil bulging deformation in BC was greater than that in SPH-FEM, the result of the former was more conservative. Moreover, the BC is dominated by the blasting cavity radius, i.e. it cannot be modeled when the radius is larger than the depth of an equivalent explosion. According to the pressure time history curve of the soil unit under the action of detonation wave, the pressure propagation characteristics were analyzed. Finally, the stress and deformation of the attack surface, top surface, back surface and bottom surface of a pipe were analyzed. The research evaluated the advantages and disadvantages of the existing explosion simulation approaches, which can provide technical references for the reliability analysis and risk prevention and control of parallel gas pipelines under extreme disasters.