Seismic loss and resilience assessment of single-column rocking bridges

This study focuses on structural systems, which are particularly attractive for bridge design. Specifically, it investigates the seismic performance of single-column bridges, which are either conventionally designed, with the column monolithically connected with the ground (i.e. fixed-base), or designed with the column-footing system able to uplift and exhibit planar rocking motion during an earthquake. Although various researchers have studied the examined structures in terms of their seismic fragility, their seismic losses, post-earthquake functionality and resilience have received less attention. This paper redirects our attention to the main benefits of rocking design over the conventional (fixed-base) design in the aftermath of severe seismic hazard scenarios. The analysis reveals the considerably mitigated (short-term and long-term) seismic losses of the rocking structure compared to the pertinent losses of the fixed-base structure. In addition, the results show the remarkable functionality and resilience of the rocking structure after all the examined seismic hazard scenarios. Importantly, this work unveils that the post-earthquake financial benefits of the rocking structure can be further increased when the structure is carefully designed. In particular, even a small modification of its slenderness can lead to a substantial enhancement of its post-earthquake performance. The above findings illustrate the potential of the rocking structural system as an alternative seismic design paradigm for bridges and serve as the basis for a more rational and holistic seismic assessment framework of single-column rocking bridges.