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[SEAOC] Steel Beam to Column and 3Rw/8 question

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I've design a Waffel-crete building that contains an interior mezzanine
with a large cut-out in the center. The Waffel-crete walls carry all
lateral loads and the interior steel supports the mezzanine and portions of
the roof girders (panelized roof construction).
In the design of the steel for the mezzanine, I have considered the
material weight (plus 25% of the live storage load) and, from this,
determined a lateral load to each edge of the mezzanine.
When I designed the steel, I designed it as a frame with both gravity loads
and lateral loads. Even though the edges of the frame are connected to the
Waffel-crete structure, I wanted to design enough stiffness into the frame
to control story drift as if it were free standing.
The columns are W8x31 members and the beams W14x30's.
When the plan check corrections came back, I was asked to design the beam
to column connection capable of resisting a moment increase of 3*Rw/8 or
2.25 times the beam moment. 

Is this requirement (which increases the cost by eliminating bolted
connections and requiring field welding) necessary for a "secondary" type
structure whose purpose is to support static loads only and not intended to
control the building drift? Drift was considered simply from the static
loads of the mezzanine and did not consider the roof or walls which are
attributed to the Waffel-crete.
The beam yielded a maximum moment of 70 foot-kips and a reaction of 14.5
kips. This would mean designing the bolted connection for a revised moment
of 158 foot-kips.

Comments on this would be greatly appreciated.
Dennis Wish PE

Respond to: wish(--nospam--at)
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