An Abstract of a Thesis a Comparison of Load Factor Rating (LFR) and Load And Resistance Factor Rating (LRFR) in Reinforced Concrete Box and Slab Culverts

Аннотация

Load rating of new and existing bridges have been used in state departments of transportation for decades as a method to determine if a bridge is adequate for the expected vehicle traffic on the bridge. Currently, there are several methods available for rating existing bridges; each method is similar to its corresponding design philosophy. The two primary methods used in state departments of transportation are Load Factor Rating (LFR) and Load and Resistance Factor Rating (LRFR). Previously, the reinforced concrete culverts in Tennessee, which is approximately 40% of the bridge inventory, were not load rated. This was because they were not considered critical structures. However, a Federal Highway Administration (FHWA) mandate requires that all existing culverts be load rated. Also, FHWA recommends that LRFR be used on existing culverts in lieu of LFR. The objective of this research was to provide an accurate comparison of LFR to LRFR for reinforced concrete box and slab culverts. It was also necessary to check if the FHWA recommendation is valid or not.