Bridge Analysis and Rating with Microcomputers

Abstract

A software system is developed to analyze the rate existing bridges. The system is capable of rating simple truss and continuous girder bridges up to three spans. Composite and noncomposite steel girders and concrete T‐beam bridges are supported. Girder bridge cross‐sectional properties may vary along each span. Five standard American Association of State Highway and Transportation Officials (AASHTO) trucks and one user‐defined truck are supported. The analysis methods selected are chosen to minimize computer resources. A wide variety of output related to bridge behavior is available. Two examples, a two‐span girder bridge and a four‐panel Pratt Truss bridge, are presented. Identical results are obtained from microcomputers with 8088 or 80286 processors. However, the microcomputers with the 80286 processors conducted the analysis and rating approximately 2.5 times faster. For the 80286‐based microcomputers, the run time for the two‐span bridge varied between 1 minute 12 seconds and 2 minutes 52 seconds. With the proper software, microcomputers will assist those individuals responsible for inspecting and rating the approximately 570,000 bridges in the country.