Skewed Bridge and shear in the exterior beams

QUESTION: The shear in the exterior beam at the obtuse corner of the bridge shall be adjusted when the line of support is skewed (AASHTO LRFD Bridge design specifications – Section wonder how CONSPAN handles the correction factors shown on Table of the AASHTO.


Angle between the centerline of a support and a line normal to the roadway centerline. Used for adjusting LRFD distribution factors, as specified in Art. and Art.
CONSPAN allows the user to enter a starting skew angle as well as an ending skew angle for each span. In LRFD mode, when using the AASHTO formulae for computing the Moment Distribution skew correction factors, the smaller of these two angles is used. When computing the Shear Distribution skew correction factors, the larger of the two skew angles specified for the spans is used. When the refined method of analysis is used in either specification mode, the program sets up the grillage model considering the true bridge geometry created by these two skew angles. The input fields are grayed out in the Standard Specifications (LFD) mode, unless the option to use refined methods of analysis has been selected in the Analysis Factors dialog box.

The user does NOT have to calculate the skew correction factor for shear by hand as the program will model true skew supports and distribute the loading.

The skew correction factor is applied for the entire beam at all location.