# 18.4 Intermediate Moment Frames

**in tension at the face of support.**

*f*_{y}*V*shall be at least the lesser of (a) and (b):

_{n}(a) The sum of the shear associated with development of nominal moment strengths of the beam at each restrained end of the clear span due to reverse curvature bending and the shear calculated for factored gravity loads

(b) The maximum shear obtained from design load combinations that include ** E**, with

**taken as twice that prescribed by the general building code**

*E***2**measured from the face of the supporting member toward midspan. The first hoop shall be located not more than 2 in. from the face of the supporting member. Spacing of hoops shall not exceed the smallest of (a) through (d):

*h*(a) *d*/4

(b) Eight times the diameter of the smallest longitudinal bar enclosed

(c) 24 times the diameter of the hoop bar

(d) 12 in.

*V*shall be at least the lesser of (a) and (b):

_{n}(a) The shear associated with development of nominal moment strengths of the column at each restrained end of the unsupported length due to reverse curvature bending. Column flexural strength shall be calculated for the factored axial force, consistent with the direction of the lateral forces considered, resulting in the highest flexural strength

(b) The maximum shear obtained from factored load combinations that include ** E**, with

**Ω**substituted for

_{o}E

*E***over a length**

*s*_{o}**measured from the joint face. Spacing**

*ℓ*_{o}**shall not exceed the smallest of (a) through (d):**

*s*_{o}(a) 8 times the diameter of the smallest longitudinal bar enclosed

(b) 24 times the diameter of the hoop bar

(c) One-half of the smallest cross-sectional dimension of the column

(d) 12 in.

Length ** ℓ_{o}** shall not be less than the greatest of (e), (f), and (g):

(e) One-sixth of the clear span of the column

(f) Maximum cross-sectional dimension of the column

(g) 18 in.

**, spacing of transverse reinforcement shall be in accordance with 10.7.6.5.2.**

*ℓ*_{o}**in accordance with 18.4.3.3 over the full height beneath the level at which the discontinuity occurs if the portion of factored axial compressive force in these members related to earthquake effects exceeds**

*s*_{o}**. If design forces have been magnified to account for the overstrength of the vertical elements of the seismic-force-resisting system, the limit of**

*A*/10_{g}f'_{c}**shall be increased to**

*A*/10_{g}f'_{c}**. Transverse reinforcement shall extend above and below the column in accordance with 18.7.5.6(b).**

*A*/4_{g}f'_{c}**γ**. Effective slab width for exterior and corner connections shall not extend beyond the column face a distance greater than

_{f}M_{sc}**measured perpendicular to the slab span.**

*c*_{t}**at the face of support as defined in 8.10.3.2.1.**

*f*_{y}### Related Code Sections

*intermediate*

*moment*

*frames*including two-way slabs without beams forming part of the seismic-force-resisting system ...

*moment*strength at the face of the joint shall be at least one-third the negative

*moment*strength provided at that face of the joint ...

*Beams*> 18.4.2.2

*intermediate*

*moment*

*frames*including two-way slabs without beams forming part of the seismic-force-resisting system ...

*Scope*> 18.4.1.1

*Beams*> 18.4.2.1

*moment*strengths of the beam ...

*Beams*> 18.4.2.3