248 CHAPTER NINE
For horizontal shear distribution, the seismic design story shear in any story,
Vx, is determined by the following:
(9.145)whereFithe portion of the seismic base shear induced at level i. The seismic
design story shear is to be distributed to the various elements of the force-
resisting system in a story based on the relative lateral stiffness of the vertical
resisting elements and the diaphragm.
Provision also should be made in design of structural framing for horizontal
torsion, overturning effects, and the building drift.
Vx
n
i 1 Fi