ABSTRACT
The successful past performance of an existing bridge may reduce the uncertainty associated with the bridge resistance and so increase the bridge reliability. However, the resistance deterioration and the increase in traffic load may negate this effect. In this paper, statistical techniques are used to combine the prior estimate of time-dependent resistance with new information from the service load history, thereby obtaining an updated estimate of bridge resistance. The influences of the intensity and non-stationarity of service load history, the shape and variance of deterioration function on updated estimates of bridge resistance are examined. It is found that the updated resistance of an existing bridge with ever-increasing traffic load is close to that of the same bridge with stationary traffic load process if the mean load intensities at the latest stage of the two load processes are identical. The statistics of deterioration function has significant effect on the updated resistance of the bridge, while the shape of deterioration function has insignificant effect on the updated resistance.
