§10. [E2] Intermediate Moment Frames (IMF)

§10.2 Beam-to-Column Joints and Connections

When calculating the required shear strength per 9.2a (by reference from 10.2) all standard provision load combinations with seismic load cases are considered, replacing the seismic load case and factor with the force produced from a term 1.0E where E = 2.0 [1.1 Ry Mpr] / L. The 1.0 load factor will replace the load factor associated with the seismic load case in the underlying load combination. L is taken as the distance between reduced beam sections, if they exist, otherwise L is the distance between the face of the columns supporting the beams. Mpr is the ultimate strength of the beam in bending at the reduced beam section, if it exists, otherwise it is from the full beam section.

Note: For ASD the Mpr term is not divided by Ω (1.5) as is typically performed in other similar calculations such as 9.3a. This may produce conservative shear forces for ASD design if the Ω factor is then assigned to the capacity calculations.

IMF connections are required to be prequalified, refer to the AISC 358-05 for more information.

All SidePlate beam-to-column joints demonstrate conformance with 10.2a as indicated in 10.2b per ICC-ES ESR-1275

§10.4a [E2.5a] Beam and Column Limitations

Refer to the requirements of 8.2a – Only AISC 360 B4.1 limits are required to be met.

§358-05 5.3.1 [358-10 5.3.1, 358-16 5.3.1] Beam Limitations

If AISC358-05 Section 5.3.1 RBS Moment Connections are designated in the Codes dialog box then all the additional Beam Limitation requirements of this section, beyond those of 341-05, will be performed. For 5.3.1(2) the beam depth will be used to assess if the section size exceeds the largest W36 section depth. It may be possible however that a beam with greater depth is appropriate (or shallower depth inappropriate) if they are not pre-qualified.

§358-05 5.3.2 [358-10 5.3.2, 358-16 5.3.2] Column Limitations

If AISC358-05 Section 5.3.2 RBS Moment Connections are designated in the Codes dialog box then all the additional Column Limitation requirements of this section, beyond those of 341-05, will be performed.

§10.5 [E2.6f] Continuity Plates

If AISC358-05 RBS Connections are designated by the engineer in the Codes dialog then the 358-05 2.4.4 requirements will be performed. In this check the program will assess the column dimensions and indicate when stiffeners are required to be provided.

§10.8 [E2.4a] Lateral Bracing of Beams

Pertinent detailing information regarding stiffness and spacing of lateral bracing required of beams is provided.

Beams framing into the side of a lateral girder are assumed to brace both the top and bottom flange of the girder.

Joists framing into the side of a lateral girder are assumed to brace only the top flange of the girder.

If required the engineer can assign user brace points to all lateral beams to meet this provision. The user brace points should represent actual physical bracing to be provided on the constructed beam.