About the research
Accelerated bridge construction (ABC) techniques are rapidly gaining acceptance as an alternative to conventional construction to reduce construction duration and minimize the impact of closures at the network level. There are different types of ABC and each technique has its limitations and speed of completion. The choice of using a specific ABC depends on a host of different factors including its applicability to specific bridge site, criticality of the bridge to the network, and availability of capital funds for its implementation. Some of these factors tend to have contradicting affects, as a faster ABC technique often entails higher investment levels; on the other hand, a faster technique for a bridge with high criticality to the network may result in large savings in user costs.
This report details the development of a mixed-integer programming model that provides a balanced portfolio of construction techniques on bridge sites over a prioritization process for bridges at the network level. For this purpose, while a network-level scheme is used to select the bridges for rapid replacement based on their criticalities to the network, a project-level scheme accordingly is conducted to optimize the choice of accelerated construction techniques. To account for the effects of different accelerated construction techniques, the costs associated with each replacement technique is calculated including direct costs from the actual replacement of bridges and indirect costs experienced by network users due to the bridge closure during the maintenance period.
Using the mixed-integer programming model, based on the investment budget, the new service performances of bridges, and the optimal accelerated construction techniques for different bridges, the bridge replacement strategy and the costs during the entire process are estimated, which could provide the decision-makers and stakeholders a detailed understanding of the prioritization process at both the network and project level.