ABSTRACT
A very important design consideration in fra~t~es with PR connections Is ttte drift of tttese frames. The less the connection restraint, the Rlore ttte drift. Much researctt has been focused on ttte ulti~t~ate loads needed on frames with PR connections for collapse and shal<.e down. Fro~t~ a practical designer's view, allowable drift limits for damage or occupant comfort seem to always come before a fraftle is even close to collapse. The fact is especially true if one adopts the philosoptty of using the minimum connection restraint reauired for tile actual de~t~ands. The writer's experience ttas been that alftlost without fail, drift reauires the most connection restraint, not gravity loads. In the writer's designs, drift is controlled by selectively adjusting the available connection restraint to the de~t~and. If one follows that procedure, a safe t-uilding design controlled by allowable drift will result.
