Burgess & Niple was retained by the Arizona DOT to perform in-depth inspections
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