AISC ASD Approach. Beams may be supported directly on concrete or masonry if the bearing pressure is within the allowable. The flanges, however, will act as cantilevers, loaded
When the bearing pressure under a beam flange exceeds the allowable, a bearing plate
should be inserted under the flange to distribute the beam load over the concrete or masonry.
The beam load may be assumed to be uniformly distributed to the bearing plate over an area of 2kN, where k is the distance (in) from bottom of beam to web toe of fillet and N is the length of plate (Fig. 5.40).
Beams usually are not attached to bearing plates. The plates are shipped separately and
grouted in place before the beams are erected. Wall-bearing beams usually are anchored to the masonry or concrete. Government anchors (Fig. 5.41) generally are preferred for this purpose.