The primary objective of the structural evaluation of the John A. Roebling Bridge is to determine the maximum allowable gross vehicle weight (GWV) that can be carried by the bridge deck structural elements such as the open steel grid deck, channels, standard sections, or built-up sections. To achieve this objective, four levels of analysis are carried out: "Element Level", "Sectional level 1", "Sectional level II", and "Global level" analysis.

The four levels of analysis yield a load envelope that encapsulates the maximum and minimum allowable loads. The maximum allowable gross vehicle weight (GWV) for different truck and bus types are presented for different levels of structural elements sectional loss. The loss or reduction in element sectional properties is due to rust, cracks, etc.

The "Element Level Analysis" is the most critical and yielded the maximum allowable gross vehicle weights. The critical member in the bridge deck is the built-up 36 inch deep section. Its allowable bending strength controls the maximum "Gross Vehicle Weight" (GVW) that can be permitted on the bridge. Results are presented for different levels of sectional losses (10% to 40%, in 10% increments).

In the event that replacement of the open grid deck will take place in the future, results are presented for different deck weights (10 psf to 50 psf in 10 psf increments). The current open grid deck weight is 20 psf.

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The contents of this report reflect the views of the authors who are responsible for the facts and accuracy of the data presented herein. The contents do not necessarily reflect the official views or policies of the University of Kentucky, the Kentucky Transportation Cabinet, nor the Federal Highway Administration. This report does not constitute a standard, specification or regulation. Manufacturer or trade names are included for identification purposes only and are not to be considered an endorsement.