15.4column-beam relationship limitations

Beam-to-column connections shall satisfy the following limitations.

Column-beam moment ratios shall be limited as follows.

• (a) For SMF systems, the column-beam moment ratio shall conform to the requirements of the AISCE Seismic Provisions. The value of $\sum M_{p b}^{*}$ shall be taken equal to:

$\Sigma\left(M_{p r}+M_{u v}\right)$

where

$M_{p r}=$ probable maximum moment at the fuse determined in accordance with Section 2.4.3, kip-in. (N-mm)

$M_{u v}=V_{b}\left(d_{c} / 2\right)$, kip-in. (N-mm)

$V_{b}=2 M_{p r} / L_{h}+V_{g}$, kips (N)

$L_{h} \quad$ = clear distance between column faces, in. (mm)

$\begin{aligned} V_{g} & =\text { beam shear caused by gravity loads based on the load combination } \\ & 1.2 D+f_{1} L+0.15 S, \text { where } f_{1} \text { is the load factor determined by the } \\ & \text { applicable building code for live loads, but not less than } 0.5, \text { kips (N) }\end{aligned}$

$d_{c}$ = depth of column, in. (mm)

The value of $\sum M_{p c}^{*}$ shall be the sum of the projections of the nominal flexural strengths, $M_{p c}$, of the column above and below the joint, at the potential hinge location located one-quarter of the column depth above and below the cover plates edges.

• (b) For IMF systems, the column-beam moment ratio shall conform to the require- ments of the AISCE Seismic Provisions.