The connections contained in this standard are prequalified in accordance with the requirements of the AISC Seismic Provisions when used to connect members meeting the limitations of Sections 2.3.1, 2.3.2, or 2.3.3, as applicable.
2.3.1 Rolled Wide-Flange Members
Rolled wide-flange members shall conform to the cross-section profile limitations applicable to the specific connection in this standard.
2.3.2 Built-up Members
Built-up members having a doubly symmetric, I-shaped cross section shall meet the following requirements:
- (1) Flanges and webs shall have width, depth, and thickness profiles similar to rolled wide-flange sections meeting the profile limitations for wide-flange sections applicable to the specific connection in this standard, and
- (2) Webs shall be continuously connected to flanges in accordance with the require- ments of Sections 2.3.2a or 2.3.2b and the requirements of the AISC Seismic Provisions, as applicable.
2.3.2a Built-up Beams
Within a zone extending from the beam end to a distance not less than one beam depth beyond the plastic hinge location, , the web and flanges shall be connected using complete-joint-penetration (CJP) groove welds with a pair of reinforcing fillet
| Connection Type | Chapter | Systems |
|---|---|---|
| Reduced beam section (RBS) | 5 | SMF, IMF |
| Bolted unstiffened extended end plate (BUEEP) | 6 | SMF, IMF |
| Bolted stiffened extended end plate (BSEEP) | 6 | SMF, IMF |
| Bolted flange plate (BFP) | 7 | SMF, IMF |
| Welded unreinforced flange-welded web (WUF-W) | 8 | SMF, IMF |
| Cast bolted bracket (CBB) | 9 | SMF, IMF |
| ConXtech ConXL (ConXL) | 10 | SMF, IMF |
| SidePlate | 11 | SMF, IMF |
| Simpson Strong-Tie Strong Frame | 12 | SMF, IMF |
| Double-tee | 13 | SMF, IMF |
| Slotted web (SW) | 14 | SMF |
| DuraFuse Frames | 15 | SMF, IMF |
welds unless specifically indicated otherwise in this standard. The minimum size of these fillet welds shall be the lesser of 5/16 in. (8 mm) and the thickness of the beam web.
2.3.2b Built-up Columns
Built-up columns shall conform to the provisions of subsections (1) through (4), as applicable. Built-up columns shall satisfy the requirements of the AISC Specification, except as modified in this section. Transfer of all internal forces and stresses between elements of the built-up column shall be through welds.
(1) I-Shaped Columns
The elements of built-up I-shaped columns shall conform to the requirements of the AISC Seismic Provisions.
Within a zone extending from 12 in. (300 mm) above the upper beam flange to 12 in. (300 mm) below the lower beam flange, unless specifically indicated in this standard, the column webs and flanges shall be connected using CJP groove welds with a pair of reinforcing fillet welds. The minimum size of the fillet welds shall be the lesser of 5/16 in. (8 mm) and the thickness of the column web.
Exception: For SidePlate moment connections, each column flange may be connected to the column web using a pair of continuous fillet welds. The required shear strength of the fillet welds, , shall equal the shear developed at the column flange-to-web connection where the shear force in the column is the smaller of
- (a) The nominal shear strength of the column per AISC Specification Equation G2-1.
- (b) The maximum shear force that can be developed in the column when plastic hinge(s) form in the connected beam(s).
(2) Boxed Wide-Flange Columns
The wide-flange shape of a boxed wide-flange column shall conform to the requirements of the AISCE Seismic Provisions.
The width-to-thickness ratio, , of plates used as flanges shall not exceed , where shall be taken as not less than the clear distance between plates.
The width-to-thickness ratio, , of plates used only as webs shall conform to the requirements of the AISC Seismic Provisions.
Within a zone extending from 12 in. (300 mm) above the upper beam flange to 12 in. (300 mm) below the lower beam flange, flange and web plates of boxed wide-flange columns shall be joined by CJP groove welds. Outside this zone, plate elements shall be continuously connected by fillet or groove welds.
(3) Built-up Box Columns
The width-to-thickness ratio, , of plates used as flanges shall not exceed , where shall be taken as not less than the clear distance between web plates.
The width-to-thickness ratio, , of plates used only as webs shall conform to the requirements of the AISC Seismic Provisions.
Within a zone extending from 12 in. (300 mm) above the upper beam flange to 12 in. (300 mm) below the lower beam flange, flange and web plates of box columns shall be joined by CJP groove welds. Outside this zone, box column web and flange plates shall be continuously connected by fillet welds or groove welds.
Exception: For ConXL moment connections, partial-joint-penetration (PJP) groove welds conforming to the requirements of Section 10.3.2 shall be permitted within the zone extending from 12 in. (300 mm) above the upper beam flange to 12 in. (300 mm) below the lower beam flange.
(4) Flanged Cruciform Columns
The elements of flanged cruciform columns, whether fabricated from rolled shapes or built up from plates, shall meet the requirements of the AISC Seismic Provisions.
Within a zone extending from 12 in. (300 mm) above the upper beam flange to 12 in. (300 mm) below the lower beam flange, the web of the tee-shaped sections shall be welded to the web of the continuous I-shaped section with CJP groove welds with a pair of reinforcing fillet welds. The minimum size of fillet welds shall be the lesser of 5/16 in. (8 mm) or the thickness of the column web. Continuity plates shall conform to the requirements for wide-flange columns.
Exception: For SidePlate moment connections, the web of the tee-shaped section(s) may be welded to the web of the continuous I-shaped section with a pair of continuous fillet welds. The required strength of the fillet welds, , shall equal the shear developed at the column web to tee-shaped section connection where the shear force in the column is the smaller of
- (a) The shear strength of the column section per AISC Specification Equation G2-1.
- (b) The maximum shear that can be developed in the column when plastic hinge(s) form in the connected beam(s).
2.3.3 Hollow Structural Sections (HSS)
The width-to-thickness ratio, , of HSS members shall conform to the requirements of the AISC Seismic Provisions and shall conform to additional cross-section profile limitations applicable to the individual connection as specified in the applicable chapter.
2.3.4 Isolation of Concrete Slab
Where an individual connection requires isolation of the concrete slab, the column and connection elements at the face of the column shall be isolated from the concrete slab such that the rotation of the frame beam relative to the column joint is unimpeded by the concrete slab.