| In the aftermath of the collapse of the I-35W over Mississippi River Bridge in Minnesota, the Federal Highway Administration (FHWA) issued a technical advisory to bridge owners to check the status of similarly-designed bridges. It was determined that under-designed gusset plates contributed to the collapse. This sparked a nationwide effort to investigate the design of these connection members and to develop more detailed specifications for future gusset plate design. In order to thoroughly study complicated bridge elements such as gusset plates, sophisticated analysis techniques are required. One such technique is finite element modeling (FEM), which is used here to identify critical loading cases for typical Warren truss gusset plates.;The specific gusset plates studied here are located on two bridges, herein referred to as Bridge A and Bridge B, that are similar in design to the I-35W Bridge. Following the I-35W collapse, independent investigations, which included finite element analysis, were initiated on both bridges. In this thesis, information from these investigations is used to develop a comprehensive FEM, which facilitates more in-depth analysis of such gusset plates. The analysis focuses on the investigation of stresses created in the gusset plates by various types of live loading. The results are compared to the Method of Sections approach recommended by FHWA following the I-35W Bridge collapse to determine if better analysis specifications are needed. Although the results of the finite element analysis and the Method of Sections approach are similar, the authors conclude that the value of the Method of Sections approach is strongly dependent on the accuracy of the load data input. Therefore, more detailed specifications are needed to ensure the accuracy of future gusset plate analysis and design. |
