Numerical derivation of P-I diagrams for shallow buried RC box structures

Abstract

To perform quick damage assessment and preliminary blast resistant design, the present study develops Pressure-Impulse (P-I) diagrams for the shallow-buried box structures based on high fidelity numerical modelling. Shock wave propagation in the soil and its interaction with the roof slab and vertical wall are considered in the blast load modelling, both flexure and shear damage of the roof slab under surface blast loads are considered in the P-I diagram. Parametric studies are carried out to investigate the effects of roof span, wall thickness, concrete strength, flexure and shear reinforcement ratio on the P-I diagram. Based on the numerical results, analytical formulae to predict the P-I diagrams for buried box structures are derived. The applicability of the improved P-I diagrams approaches in practical evaluation is illustrated through case studies.