In-situ Investigation of Distribution Factors and Impact Factors for Enhancing Design of Box Beam and Plank Girder Bridges with Continuous Deck Slab

Abstract

This paper presents in-situ investigation of distribution factors and impact factors for enhancing design of box beam and plank girder bridges with continuous deck slab. Analysis of measured strains reveals that skew angle and sidewalk have significant effect on girder distribution factors (GDFs) and impact factors (IMs) whereas span continuity has only little influence. Bridges without or with slightly skewed and/or in absence of sidewalk can distribute live load better than bridges with highly skewed and/or in the presence of sidewalk. Statistical maximum GDFs and IMs of bridges without or with slightly skewed and/or in absence of sidewalk are lowers than those of bridges with highly skewed and/or in the presence of sidewalk. Statistical maximum GDFs and IMs of bridges without or with slightly skewed and/or in the absence of sidewalk correspond with GDFs and IMs suggested in AASHTO LRFD (2007 SI) specifications whereas statistical maximum GDFs and IMs of bridges with highly skewed and/or in the presence of sidewalk correspond with GDFs and IMs suggested in AASHTO STANDARD (2002) specifications. It is recommended that GDFs and IMs suggested in AASHTO STANDARD (2002) shall be used in the design of highly skewed and/or in the presence of sidewalk of box beam and plank girder bridges with continuous deck slab.