Load Distribution in Short and Medium Span, Shear-connected, Precast Beam Bridges Under CHBDC Truck Loading

The 2019 Canadian Highway and Bridge Design Code recognized shear-connected Tee, DoubleTee and inverted-U precast beams to accelerate bridge construction. However, a simplified live load method of analysis of this type is yet unavailable. Therefore, a parametric study was conducted using the Orthotropic Plate Theory to determine the transverse vertical shear required to design the shear key between adjacent beams as affected by bridge span and width, flexuraltorsional parameter, and loading conditions. This study resulted in six charts for this shear force for one-lane to six-lane bridge configurations. Another parametric study was conducted to determine the truck load fraction carried by each beam, leading to empirical equations for moment and shear distribution factors required for beam design. Another analysis was conducted to investigate the applicability of the AASHTO Lever Rule method on this bridge type. Based on the analysis findings, this method was modified to include the effect of beam spacing and span and flexural-to-torsional stiffness ratio.