HORIZONTALLY CURVED I-GIRDER BRIDGE ANALYSIS: V-LOAD METHOD

The V-load method is a widely used approximate method for the analysis of horizontally curved I-girder highway bridges. Previously, this method had been proven valid only for noncomposite I-girder bridges with radial supports. Thus, a study was made to extend the method to composite I-girder bridges with any general support configuration. Vload-analysis results for noncomposite and composite I-girder bridges under dead load and live load were compared with the corresponding results from three finite-element curved bridge models with different combinations of radial and skewed supports. The dead-load V-load results were extremely accurate. The live-load V-load results were strongly influenced by the lateral distribution factors that were used; specification distribution factors gave acceptable V-load results for exterior girders and conservative results for interior girders. More accurate results were obtained with more realistic factors. It is also shown that the V-load method is not a valid approximation for closed-framed I-girder systems with horizontal lateral wind bracing. Approximate expressions are presented to compute the warping stresses in the girder flanges, an important consideration in curved I-girder bridges.