Burgess & Niple was retained by the Arizona DOT to perform in-depth inspections and load ratings of 173 steel arch, truss, girder and beam bridges up to 1,200 feet long and 700 feet high. Bridges were located throughout the northern and eastern portions of Arizona. Structures include the Glen Canyon and Navajo Bridges, the state’s largest arch and truss bridges, respectively.
Load ratings were performed using AASHTO’s VIRTIS load-rating program for the girder and beam bridges and GT-STRUDL for the more complex structures. A load-rating summary report was produced for each structure which contained inventory and operating ratings for HS20 loadings, location of controlling member, failure mode with limit state, posting recommendation, and general bridge information.
Plans and specifications were prepared to repair 22 bridges, most of which had fatigue-related cracks.