Perimeter Deck Attachments at Protected Zones

[skeletron]

CSA S16 Clause 27.1.9 defines protected zones. Specifically:
"...welded shear studs and decking attachments that penetrate the beam flange shall not be placed on the beam flanges within protected zones unless approved by the engineer. Arc-spot welds necessary to secure decking to beam flanges may be used..."

The Commentary goes on to explain:
"...Hence, unless engineered or part of test assemblies satisfying the specified performance, welded, bolted, screwed, or shot-in attachments for perimeter edge angles...shall not be placed within protected zones..."

I have a simple structure (box). Moment frames in one direction, braced frames in the other. I'm using Bolted Flange Plate Moment Connections. The protected zone of the moment frame extends from the face of the column to one beam depth beyond the bolts farthest from the column. So, for argument sake the protected zone is approximately 22" from the face of the column (furthest bolts are ~10" from the face of the column, W12 beam).

How do I connect the perimeter angle to the moment frame beam in the protected zone? An example detail of a similar structure is attached. It appears that my only option would be to arc-spot the deck to the beam in the protected zone and weld the bent plate? Maybe I'm looking for clarification here because I always thought the preference was to screw attach the deck to structure due to ductility reasons.

 

[Deker]

You don't attach the bent plate to the protected zone. It either hangs free or spans over the protected zone to an outrigger on the column.

For deck attachment you can use puddle welds or shotpins up to 0.18" diameter (AISC 341-22 I2.1). Fasteners may encourage more ductile behavior in the diaphragm, but they can potentially lead to beam fracture when placed in the protected zone.