Resistance and time-variant reliability updating of existing bridge structures based on proof loads

Based on the characteristics of existing structures, the analyses were presented for an effect on the resistance of existing structures by using deterministic loads and stochastic loads. The calculating equations of the normal distribution and logarithmic normal distribution resistance under the deterministic proof load and the stochastic proof load were presented. Some valuable conclusions have been obtained for the calculating reliability of the existing structures. Based on the conclusions, time-dependent reliability model of the existing bridges was updated, the timedependent reliability indices were solved with time integrated-discretized approach, and finally the numerical examples were presented.