Optimal maintenance times of corroded bridges including climatic change and Kernel improvement to the simulation process

Abstract

The corrosion degrades the bridge capacity in such a way that its vulnerability is challenged and its maintenance rises serious concerns. If the effect of climatic change is added, the corrosion process is accelerated and the prediction of the time when a maintenance work is required should be a careful exercise. Uncertainties are also of the utmost importance and, in particular, the corrosion hazard requires a probabilistic model. In this work, a procedure to assess the optimal maintenance times of prestressed concrete bridges is proposed and an emphasis is placed on the corrosion rate which is considered random and several climatic change scenarios make variable its mean value and the standard deviation. By recognizing that, in a bridge network, the most important bridges require a more detailed follow-up, the bridge importance is considered to determine the maintenance times in terms of the size of the potential losses. The reliability reduction and the rate of reliability reduction are appraised to characterize the bridge degradation and infer the priority of the maintenance needs. The reliability is obtained from the bridge failure probability which is calculated through Monte Carlo simulations. Given that the crude Monte Carlo is very time-consuming, Kernel tools are applied to improve the calculations efficiency.This is performed for 3 climatic change scenarios and recommnedations are obtained for these scenarios and for two levels of failure consequences (bridge importance). As expected, for the worst scenarios of climatic change, the maintenance time should be anticipated. In addition, the more important bridges require also an anticipation on the required maintenance times.