Shoring Point Loads on a 5 inch Slab
Shoring Point Loads on a 5 inch Slab
(OP)
I have a 5" thick post tension slab in a parking garage. It's a one way slab spanning 18' from beam to beam. The contractor is putting about a 17 kip (D+L) point load (shoring load for floor above) about 3' from the beam on each side. He says he's done it without cribbing before (the footprint is a 7" square plate). That's a huge point load on a 5" slab. I checked punching and it is fine. But my negative bending above the beam is almost 65% overstressed. I can't figure a way around it nor how other engineers were able to justify it. Any ideas? Thanks.






RE: Shoring Point Loads on a 5 inch Slab
RE: Shoring Point Loads on a 5 inch Slab
RE: Shoring Point Loads on a 5 inch Slab
RE: Shoring Point Loads on a 5 inch Slab
I figured it was practical, I just thought I was missing something. They'll definitely need cribbing.
RE: Shoring Point Loads on a 5 inch Slab
RE: Shoring Point Loads on a 5 inch Slab
One thing I'd question a little further is this only getting reshored one floor as you've noted. If you're pouring a 5" slab, you're looking at 63 psf of normal weight concrete plus formwork/shoring and personnel loads. Would think all that would tend to come out at 2-3x higher than your typical 40 psf passenger car garage load that the floor would be expected to support in addition to its own weight. Unless garage was designed for a much heavier live or finish load or seriously overdesigned. Could be fine and I'm just missing something, but doesn't seem quite right at first glance.