In skewed bridges, the sequence of loading during construction influences magnitude of shear stresses developed in the girder supports and is usually not considered in the design. The Canadian Highway Bridge Design Code (CHBDC) and AASHTO-LRFD Bridge Design Specifications permits shored construction. However, design guidelines to estimate the accumulation of girder shear stresses due to different load conditions (i) before the concrete hardening, and (ii) after placing the asphalt layer and the barrier wall are as yet unavailable. In this paper, a three-dimensional finite-element modeling was conducted to determine the shear magnification factor in bridge girders by considering different parameters including: skew angles, girder stiffness and cross-frame layout, span length and number of design lanes under dead load conditions. Finally, the results signify the importance of considering the effect of shear magnification factors for rational prediction of support reactions and to develop more realistic design guidelines for shored and unshored sequence of construction.
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