Damage modes of shallow-buried RC oil depots subjected to the coupling of shock waves and oil-gas explosions

Scaled models of shallow-buried RC oil depots were designed by changing depots structure, the type and volume of oil, and explosion source locations to investigate the damage modes and mechanisms of shallow-buried RC oil depots subjected to the coupling of shock waves and oil-gas explosions. The research indicates that the shock wave loading on the oil depot cover causes punching-perforation failure on the blast-facing side and spalling failure on the blast-opposite side. The damage degree of the oil depot cover is greater when the depot contains 50% diesel. Two peaks appear in the overpressure rise stage of the shock wave when the oil depot contains 100% diesel while due to multiple interface reflection in the internal cavity, three peaks appear with the increase of the positive pressure duration of the shock wave when the depot contains 50% diesel. The explosion source located at the bottom of the oil depot causes severe damage to both the cover and the main depot structure. The reflection and superposition of shock waves at the corners lead to significant shear cracking at the edges of the main depot structure. Compared to the explosion of 50% diesel, the explosion of 50% gasoline produces a larger fireball with a longer burning duration, which does not cause damage to the main structure of the oil depot.