Bridge life consumption by permit vehicles.

Excessive weight and a growing number of permit vehicles can cause an accelerated bridge damage. Therefore, there is a need to better control operation of heavy permit vehicles. This paper presents an approach to assess bridge life consumption by permit loads. An economic lifetime of a bridge is considered in terms of the number of load cycles to failure so that the structure has to be replaced. Each passage of a truck causes one or more load cycles and thus reduces or consumes a part of the total remaining fatigue life. An incremental consumption equation is derived, and it allows to convert fatigue damage to dollar damage by considering the bridge construction cost, traffic volume, and bridge parameters. The incremental consumption covers only weight exceeding the legal limits. This consumption approach is presented for representative average values and the individual consumption approach with the GIS system using Florida as an example. A developed approach can help state agencies to establish a rational and fair permit fee structure. The methodology is transparent and can be used by any state utilizing the available databases. [ABSTRACT FROM AUTHOR]