P$3\mathrm{.}27.$ The baseplates at the bottoms of the columns are

connected to the foundations at points A and $D$ by bolts

and may be assumed to act as pin supports. Joint $B$ is

rigid. At $C$ where the bottom flange of the girder is bolted

to a cap plate welded to the end of the column, the joint

can be assumed to act as a hinge $($it has no significant

capacity to transmit moment$).$ Compute the reactions at

A and $D.$ P$3\mathrm{.}27$

Draw FBD