Progressive collapse of hangers in steel arch bridges due to blast loading

This work was aimed at analysing the redundancy of the hangers of a steel arch bridge and the resilient behaviour of the bridges when subjected to blast loading. Firstly, numerical models of the bridge were created to perform a linear static analysis. Then, the structure was statically verified according to Eurocode norms. Afterwards, the redundancy analysis of the bridge was conducted by considering hangers failure cases in the symmetric and asymmetric configurations. In each case considered, the failure of a particular number of hangers was considered on each side of the arch bridge, then the stress redistribution and global behaviour of the bridge was assessed. A resilience analysis was also performed through a dynamic non‐linear time‐history analysis of the bridge subjected to a blast load of 500 kg of TNT applied 1 m above the deck at two different locations on the bridge. From the redundancy analysis, a progressive collapse mechanism was found to be related to the redundancy of the hangers. Besides, the resilience analysis showed that the vulnerability of the bridge depends on the position of the blast loading. Furthermore, the level of damage of the bridge elements which is a key factor for the bridge's resilience, is dependent on their distances from the detonation point.