Performance assessment of LNG full-containment tank under explosive blast loading

Abstract

Explosive blast is a critical accidental scenario for liquefied natural gas (LNG) full-containment tanks, necessitating rigorous structural safety assessments. This study explored a method for evaluating the performance of LNG full-containment tanks subjected to explosive blast waves. The coupled Eulerian–Lagrangian technique in ABAQUS was used to simulate blast-wave propagation and resulting structural responses. The method was validated using empirical formulas and experimental data. A 270,000-m³ LNG full-containment tank was analyzed as a case study, and the explosion overpressure and structural responses at various locations on the tank were assessed. This study further examined the effects of detonation height and distance on tank performance using structural damage to the outer concrete wall of the tank as an evaluation indicator. Results indicated that the zone of elevated blast overpressure was primarily confined to a vertical range extending up to twice the detonation height and a horizontal angular spread of ±10° from the blast epicenter. The peak structural response of the tank was observed with a noticeable delay after the maximum explosion overpressure was applied, reflecting the tank's dynamic reaction to the sudden blast loading. The prestressing system significantly enhanced the tank blast resistance. Greater detonation heights caused more severe damage to the LNG tank and increased explosive distances reduced the damage. However, an explosion source located too low caused excessive damage to the foundation slab. Therefore, the detonation height should not be less than 0.3 times the outer wall height. These findings support safer design and risk mitigation strategies for LNG storage facilities.