Subject: AISC Seismic Provisions, Part I, Sect. 11.2a
From: Eddie Gonzalez <Eagonzal(--nospam--at)ENG.CI.LA.CA.US>
Date: Fri, 04 Jun 1999 16:33:48 -0700
Could someone verify if the following interpretation is correct?
11. Ordinary Moment Frames (OMF)
11.2 Beam-to-Column Joints and Connections
11.2a. [Moment Connections]
11.2a.1 states: "FR moment connections that are part of the Seismic Force
Resisting System shall be designed for a required flexural strength Mu that is
at least equal to 1.1RyMp [Ry=1.1 for A572,Gr50] of the beam or girder or the
maximum moment that can be delivered by the system, which ever is less.
This seems to mean that if 1.1RyMp is the least, then one may ignore Mdl & Mll.
If Meq is less, than must include Mdl and/or Mll, depending on the load
combination considered. This may seem obvious except that in item 2, for Shear
Connection, load combination that includes DL & LL & S is specifically
Other documents like FEMA 310 make this issue much more clear.