WinABUD designs or checks a reinforced concrete abutment using the 1996 AASHTO with Interims and Revisions by Caltrans."(the code) of the California Department of Transportation. The abutment may be a spread footing (with optional key) or multiple pile footing. Service load Design (SLD) or Load Factor Design (LFD) specifications may be used. The abutment is investigated for several group loads. The group loads are divided into separate load cases.
THE FOOTING is assumed to be infinitely rigid and the pile loads and footing pressures are calculated from static equations of equilibrium. for spread footings, WinABUD considers uplift and calculates a line of zero pressure (neutral axis), in addition to computing factors-of-safety for sliding and overturning.
STEEL REINFORCEMENT requirements are calculated at 5 locations: backwall at the seat level, stem at top of footing, top of footing, bottom of footing on the heel side, and bottom of footing on the toe side.
THE SLD option is based on assumptions outlined in Article 8.15 of the code. The LFD option is based on the assumptions outlined in Article 8.16
INPUT PARAMETERS to WinABUD include the following:
A table containing the area of steel required at the 3 locations based on crack control, factored moment, 1.2 times the cracking moment, 1/3 greater than required by analysis, a max. bar spacing of 18 in., and .75 times the balanced steel ratio is provided.
A table containing controlling area of steel at each bar location is printed. The table indicates the controlling load type, applied moment, neutral axis location, effective depth, required steel area, bar size, bar spacing and number of bars.
