Improved 2D-Grid Construction Analysis of Curved and Skewed Steel I-Girder Bridges

Structural analysis methods for steel I-girder bridges can be grouped in three categories: 1D line-girder, 2D-grid, and 3D finite-element analysis. This paper discusses the qualities and limitations of these techniques, and it focuses on improvements that may be implemented to 2D-grid methods to capture horizontal curvature and support skew effects effectively at little or no additional computational cost compared to traditional 2D-grid methods. The paper focuses predominantly on the problem of analyzing the noncomposite response of the structure during construction, which is of essential importance for setting girder cambers and controlling the constructed geometry. The proposed modeling techniques also can be applied to the analysis of partially composite structures during staged deck placement and to the analysis of a structure in final composite condition. Analysis results for several example bridges with challenging geometries are presented to demonstrate the application and show the impact of the proposed modeling improvements.