I am adding a steel framing in the bay under the slab with 4 corners on columns. Just dont want to support the full load, but not sure the separate part of slab and frame can share the load, and how.
I have a PT slab flat plate building, and one area will need to be upgraded as storage room. I am going to add steel framing at the bay to support the added load. Is it possible I can only support the live load and consider the PT slab itself still support the slab dead load?
Wow, a bit crazy detail for our building. We need to replace one row steel columns at a parking garage with concrete columns. I would like the slab steel framing to slide on concrete column, but I prefer 2nd option since we design the way for indoors, but outdoor garage might use the 1st option...
@BridgeSmith,
Do you have a detail of it, it sounds like 2 plates. top plate with teflon welded to base plate?
And you pick 2nd option as it's simpler?
Thanks
Which option is better:
option 1: put steel base plate on top of concrete column, then add Teflon pad on top of base plate for steel beam to sit on. so beam can slide on teflon pad.
option 2: add steel anchors on steel base plate, slot beam bottom flange, so the beam can slide on top of base...
@BAretired, that's way beyond my head. For a beam/column frame with infill wall pinned T&B, how to make it rigid or flexible, there is no slab in the elevator. I can only model them together as one diaphram, otherwise I have no idea how to proceed.
I wish I can treat the link slab and beams as...
Both big or small structures have minimal drift, less than 0.4" on top. I am ok without expansion, only worried about possible cracks in the link slab or elevator beams/columns. The concern in the case is only because we did nothing to model and design them together.
My question is, for any...
@KootK, I am so thankful and feel you ever replied every of my posts!
The main building has symmetric stair towers each end, but once connected to the outside elevator tower, will things change? We checked both individual buildings are very rigid with little drift, so I can bear with no...
The main building has two shear wall towers.
The outside elevator tower is only column-beam frame with infill block walls. We didnt specially design the tower since we design the main building and the elevator separately.
I agree no expansion in this case since both are stiff with little drift...
Yes, the elevator column frame tower is outside of the main building. Main building has one concrete shear wall stair tower each end.
I feel we still need expansion, but boss said any tower outside of main building never need isolation. Only the PT slab building need since any force on PT slab...
The tower is columns frame only with cmu between levels. it's said the main building stair walls each end limit any deflections at end, so no need for this case.
We have a similar PT slab building with concrete moment framing, it's said we need expansion since any force on PT slab would damage...
Wondering whether we should place an expansion joint between main building and elevator tower due to seismic load. Please see attached plan, 4-story building. Even this building may not need since we have shear walls in the building, deflection is small. But for moment framed building, or for PT...
Do exposed fireproofed steel beam need painting?
ground floor is parking garage and floors above are stores. it also has ceiling coverage on garage. We called for 2 layers of painting, but it would not be sticky for fireproof material.
Thanks
I always have a question for the slab on grade concrete pad design. It's not minor non important concrete pad that can ignore the frost depth by code.
Should I have a 2' thicken edge all around for the pad, or should I have 3'-6" deep edges all around so it's below frost depth.
I have seen 8"...
Thank you all for the great input! I am using 12x7x3/4 plate now, and off from edge of wall.
But I'm used to grouting the pocket, maybe I should just brick enclose it, and keep void under beam.
