Document Type



Master of Science


Civil Engineering

First Adviser

Clay J. Naito


A new short-span highway bridge system composed of inverted steel tee beams embedded in a concrete slab was developed for the Pennsylvania Department of Transportation. The connection between the concrete deck and steel tee beams is non-traditional, and is fabricated by drilling holes near the top of the steel tee beam stem, placing reinforcement bars through the holes and casting the tee beam stem into the deck. Due to the non-standard geometry of the composite steel tee concrete deck (STCD) system, the applicability of AASHTO LRFD and PennDOT DM-4 live load distribution factors were examined. Numerical models of the STCD bridge system were developed using commercial software, SAP2000. The numerical model was first validated through comparison with full-scale experimental test results and then extrapolated to examine the spectrum of STCD widths and spans that would be likely for field applications. The live load distribution factors (DFs) for the system were determined. The numerical study indicated that the DFs specified in AASHTO LRFD and PennDOT DM-4 are conservative for bending moment and shear for the new bridge system. It was observed that AASHTO and PennDOT DFs are conservative for bending moment and shear when multiple lanes are loaded. For a single lane loaded, PennDOT DF for moment is unconservative and AASTHO DF recommendations should be used.

Available for download on Saturday, February 19, 2022