Hollow core slab

[dgkhan]

I have a situation here where we need to remove and rebuild existing wall supporting (simply supported) 20 feet span, 8" Hollow core roof slab. I need to see if we shore the PC slab 4 feet away from wall, it will work and not crack etc. Also is there any way I can model it is STAAD.

 

[jike]

You need to define whether there will be LL on the roof. I suggest contacting the precaster for his advice.

 

[JStructsteel]

cant you just determine the max moment with or without live load, live load on the cantilever only, then check it against the section to see if it cracks?

 

[csd72]

jrisebo,

That method doesnt work as the post tensioning will be working against you and increasing the cantilever moment.

dgkhan,

If they can reduce it down to a 2' cantilever and there is no loading on the end then I wouldnt expect it to be a problem. At 4' I would want more info on the planks.

 

[JStructsteel]

Is the post tensioning really doing much at the ends, I agree with csd72, 2' shouldnt be a problem.