Determination of Slab Participation from Weigh-In-Motion Bridge Testing

Abstract

The objective of this paper is to determine the locations of the neutral axis and the effective flange widths for steel girder bridges that may be used in bridge design or, at least, in the bridge rating process. A study using weigh-in-motion field test results was conducted to determine the various section properties for slab-and-beam bridge structures. From the field testing of four existing bridge structures under real truck loading, the girder neutral axis is determined using several alternatives developed by the study team. The results are studied, compared, and evaluated to find the most reliable alternative for the bridge testing. The research is also extended to the determination of the effective flange width from neutral axis results and other parameters. Comparisons are made against some of the previously developed methods and design codes. Results are given in tabulated form and conclusions are drawn from the tables.