An innovative Folded Plate Girder (FPG) system bridge was constructed in Uxbridge,Massachusetts. The University of Massachusetts at Amherst collaborated with the MassDOTAccelerated Bridge Construction Program to instrument the bridge with a total of 93 gages(strain gages, pressure cells, tiltmeters, displacement transducers, and convergence gages). Datawas collected during construction, static live load testing, and long-term for twenty months. Thispaper presents data and comparisons to analysis (3-D bridge and girder modeling in SAP-2000and ANSYS and 2-D hand calculations) to present an independent evaluation of the performanceof this innovative bridge. Stresses in concrete and steel components are well below allowabledesign values through construction, long term data collection and truck load testing. Live-loadtest data indicate that the elastic neutral axis of the girders is higher than calculated, withmeasured strains being much lower than estimated from hand calculations and FE results. Thiswas partially explained by non-linearity of strains in the bottom flanges of the FPG due to shearlag when truck axles were positioned near instrumented locations, as confirmed through analysis.However, higher superstructure stiffness than expected is likely a contributor as well. Throughthe first two years of service no signs of distress have been noted and readings are within theexpected range of bridge behavior. Based on this study the FPG is an effective system foraccelerated construction of short span bridges.
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