Many existing bridges are damaged. the older these bridges are, the higher their probability of being damaged. yet, they continue tofunction and exhibit higher capacities than those associated with their designed vehicular loads. this may be the result of several factors, but the prevalent explanation among researchers today is that the existing bridges have a much greater amount of reserve strength than that anticipated by the original bridge designer. this indicates a need for determining an effective means for modeling and evaluating existing bridges, particularly for those exceeding their design life. the present study primarily reviews definitions of deterministic and probabilistic system redundancy measures which could be used in the design and evaluation of highway bridges. some of these measures are used to evaluate the redundancy of an existing steel girder bridge. in this context, corrosion and accidental damages are simulated and the bridge redundancy is evaluated by using three-dimensional nonlinear finite element and probabilistic system analyses. the bridge damage - redundancy - reliability interaction is also studied. this paper appears in transportation research record no. 1290, thirdbridge engineering conference, march 10-13, 1991, denver, colorado, volume 1.
Abstract