Multiobjective maintenance planning optimization for deteriorating bridges considering condition, safety, and life-cycle cost

Many of the currently available bridge management system tools focus on minimizing life-cycle maintenance cost of deteriorating bridges while imposing constraints on structural performance. The computed single optimal maintenance planning solution, however, may not necessarily meet a bridge manager's specific requirements on lifetime bridge performance. In this paper the life-cycle maintenance planning of deteriorating bridges is formulated as a multiobjective optimization problem that treats the lifetime condition and safety levels as well as life-cycle maintenance cost as separate objective functions. A multiobjective genetic algorithm is used as the search engine to automatically locate a large pool of different maintenance scenarios that exhibits an optimized tradeoff among conflicting objectives. This tradeoff provides improved opportunity for bridge managers to actively select the final maintenance scenario that most desirably balances life-cycle maintenance cost, condition, and safety levels of deteriorating bridges.