ABSTRACT
ABSTRACT The current research provides a broad assessment of seismic resilience of degrading bridges over their lifespans. A three span representative bridge is analysed for this purpose. Three dimensional (3D) finite element (FE) model of the bridge is developed to simulate its seismic behaviour at pristine (or, as-built) condition and at 50 years of its lifespan. Nonlinear time history analyses are performed to express seismic vulnerability of the bridge, at pristine and degraded (at 50-year) conditions, in the form of fragility curves. For evaluating seismic resilience of the bridge, losses due to bridge damage under earthquakes are estimated considering probable postevent recovery of the bridge. The loss model incorporated both direct (due to physical bridge damage) and indirect (due to bridge inaccessibility) losses. Realistic recovery functions for different bridge damage states are considered to account for post-event recovery of the damaged bridge. Outcome of the study reveals the time-dependent variation of seismic resilience of the bridge under consideration. As expected, the high values of resilience are obtained at pristine condition of the bridge, and the values gradually reduce as bridge deteriorates.
