Parametric Model for Conceptual Cost Estimation of Concrete Bridge Foundations.

Motorway bridges constitute a major part of modern transportation infrastructure networks. Interestingly, although foundations substantially influence the bridge construction cost, few studies have focused on predesign cost estimates. This paper presents a conceptual cost-estimate model for bridge foundations that involves three stages: the selection of the foundation system, the estimation of the material quantities, and the estimation of the foundation cost. It describes an easy-to-use ground classification method, which combined with a rule-based system, leads to the choice of the foundation system. This paper also describes the development of prediction models for the material quantities of different types of foundations. The significant independent variables were identified by the experts in interview sessions. Despite its drawbacks, the stepwise regression methodology was applied to see whether the results are consistent with the experts' opinion. The major assumptions underlying the correct application of the regression methodology were tested, and the necessary adjustments were made. The proposed conceptual cost-estimating methodology provides fast and reliable results that can be very useful in the early stages of a project. [ABSTRACT FROM AUTHOR]