Stress Analysis of the Haunch Region in a Rigid Frame Bridge

About the report:

The purpose of this study was to obtain an understanding of the behavior and stress distribution in the haunch region of a rigid frame highway bridge. A finite element model of the haunch of the bridge was developed to permit the prediction of stress levels within the haunch region. Loadings on this region were determined using an analytical model of the total frame. Results from an analytical model of the haunch region were compared with the results obtained from previously made field tests of the studied bridge. Stress contours of minimum principal stress in the haunch were plotted for live loading by a test vehicle placed at three locations. Areas of probable high stress concentrations were identified, and the effect of varying web and flange thicknesses on live load stress levels in these regions was determined. Current analysis procedures of the region are generally based on a method proposed by Olander. A comparison between stresses calculated in this study and those determined by Olander's method indicated that Olander's procedure may be on the nonconservative side and designers should be extremely cautious in its use. Though only one bridge configuration and haunch geometry was considered, it is believed that the results from this study can be readily extrapolated to haunch configurations in other rigid frame bridges.

Authors