Post-buckling of network arch bridges subjected to vertical loads

Bridges in service may experience accidental actions, which may alter their structural integrity. Bracing systems are provided along the arch to reduce the risk of damage or failure. In this work, the post-buckling response of a generic network arch bridge has been investigated throughout an intensive finite element analysis. Initially, a buckling analysis was carried out on the steel bridge to find out the critical live loads underlining the influence of the geometrical non-linearity of the arch on the critical overload. Then, the description of the out-of-plane structural response of the steel arches under vertical loads was presented and finally, the lateral capacity of the arch after the accidental cable loss scenario was investigated. As a result of these studies, some interesting observations were made. The critical live loads are strongly influenced by the geometrical nonlinearity of the steel arch. Besides, the non-braced arch bridges exhibit the out-of-plane behaviour identical to that of an isolated arch.