Optimal intervention strategies for multiple object types affects by both manifest and latent processes using a Markov model

In this paper a linear optimization model is presented that can be used to determine optimal intervention strategies for critical civil structures located in regions, where there is a high probability of occurrence natural hazard events. The model allows the consideration of both manifest and latent deterioration processes. The manifest deterioration process is modeled using discrete jumps between condition states as a Markov chain. The latent deterioration process is modeled by estimating the probability of failure when an object is in each manifest condition state. The probability of failure is estimated using fragility curves. Two advantages of the deterioration model compared to conventional ones are that 1) it allows the determination of optimal intervention strategies taking into consideration multiple types of objects simultaneously and 2) the probability of being condition states due to multiple types of deterioration processes. The model is illustrated by determining the optimal intervention strategy for a road link composed of one road section and one bridge where both are affected by a manifest and a latent deterioration process.