Damage impacts and failure modes on a second and third span of an RC skew highway girder bridge under surface explosion using FEM-SPH coupling and non-Explosive Reactive Armour

Engineering infrastructures and transportation networks are indispensable to a country’s socioeconomic development. Bridge, in particular, is a critical component of these networks, and their safety is vital, as their failure can stymie national growth. However, many studies were conducted on bridge performance under conventional service and dynamic loads. But, studies on explosive impacts and their protections are scarce. In addition, full-scale blast testing on bridges is unfeasible and frequently restricted by federal rules. Therefore, computer-based numerical analysis is better when guided by experimental data derived from scaled models or their components. Further, skew bridges, like straight bridges, have become popular as part of highway infrastructures. The literature addressed that 20° to 30° skew bridges are the most vulnerable to blasts. Therefore, the present work uses the computer-based coupled FEM-SPH method and non-Explosive Reactive Armour (nERA) as protective material to explore the damage responses and failure modes over a second and third span of an RC skew three-span highway girder bridge under surface blasts confined with reflected air boundary, and each span is 20.4 m in length. Further, this exploration compares the behaviour at said skew angles under the different assessable top and bottom explosions, looking at various blast wave propagations, mass losses, damage contours and particle formations, effective plastic strain, and failure modes with preventions. Finally, the study evaluates and mitigates the substantial structural damage using nERA under surface blasts in the second and third spans, signifying its potency.