Temporary shoring from slab-on-grade
Temporary shoring from slab-on-grade
(OP)
What bearing strength is usually assumed for temporary shoring supported on existing slab-on-grade? In my case, the shoring is just a safety measure while some concrete chipping and replacement is carried out at delaminated concrete due to corroded rebar caused by leakage. The total deead load on the beam is quite large (about 190 kips, but I was going to design the shoring for about half of that becasue we are not chipping the concrete away from all the rebar.
The shoring posts would be supported from heavy timber bi-directional spreaders on top of the slab-on-grade. We know that the 30 year old existing building footings were specified to be founded on 10,000 psf soil about 5 feet below the slab-on-grade. We will likley have to get a geotechnical engineer involved, but I am just curious what bearing stress on the soil that engineers have assumed when supporting temporary shoring for garage repairs, off slab-on-grade. We generally specify for new buildings that the slab-on-grade be placed on soil capable of safely supporting 500 psf or 1000 psf, depending on the floor use, but that is for permanent loads.
Question:
What soil bearing pressure do engineers generally assume for design of temporary shoring supported from existing slab-on-grade?
The shoring posts would be supported from heavy timber bi-directional spreaders on top of the slab-on-grade. We know that the 30 year old existing building footings were specified to be founded on 10,000 psf soil about 5 feet below the slab-on-grade. We will likley have to get a geotechnical engineer involved, but I am just curious what bearing stress on the soil that engineers have assumed when supporting temporary shoring for garage repairs, off slab-on-grade. We generally specify for new buildings that the slab-on-grade be placed on soil capable of safely supporting 500 psf or 1000 psf, depending on the floor use, but that is for permanent loads.
Question:
What soil bearing pressure do engineers generally assume for design of temporary shoring supported from existing slab-on-grade?






RE: Temporary shoring from slab-on-grade
Unrelated to your question: Unless the chipping that will be performed is very minor, I suggest that you reconsider designing the shoring to support only half of the dead load. We can discuss that if you want...
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RE: Temporary shoring from slab-on-grade