Investigating existing structures in the real world can help us know more about their characteristics, advantages, and disadvantages. In this... Show moreInvestigating existing structures in the real world can help us know more about their characteristics, advantages, and disadvantages. In this thesis project, the investigation was performed on two real bridges named “Yale” Bridge, and “Valleyfield” Bridge. They were owned by the CN, one of the largest railway in the North American railroad industry. First, field testing of the bridges was performed by CN. Strain gauges (devices for indicating the strain of a material) and displacement transducers (devices for indicating movement) were placed on specific points on desired elements. Then the strain and displacement data for these specific points were recorded during the time trains were passing through the bridge. These devices record the data in voltage, so calibration constants must be applied to convert the data to stress & displacement units. After that, the bridges were modeled in “SAP2000” software, and the results were compared to the data recorded in the field. In the real world, these types of bridges are behaving something between the “Truss Model” and the “Frame Model”. Our aim is to know how they exactly behave and which model they are closer to. Results are showing that although the bridges are considered “Truss Bridges”, both of them are behaving more like a “Frame” Model than a “Truss” Model. In addition, the effect of the collision strut on L0U1 was investigated. Results shows that having this collision strut leads to the larger bending moment on L0U1 in comparison to lack of this member on the bridge. Finally, with respect to our results, “Adjustment Factors” for three different groups of diagonal, horizontal, and vertical members were provided in order to improve load rating analysis in the future. M.S. in Civil Engineering, May 2015 Show less
