Had a call the other day from a guy that wants to slab jack a concrete slab. I told him we could probable do it I would have to look at it. Then he told me it had 50 tons on top of it. Has anyone ever jack anything this heavy? I will have to go and look at it to get the size of the slab and the condition of the slab.
If the load is on an area of 10' x 30' = 300 sq ft x 144 (sq in / sq ft) = 43200 sq in
100,000lb / 43200sq in = 2.31481481 psi to lift the load.
Obviously, you'd want to concentrate the mud under the load, a manifold system would likely serve best to distribute the pressure evenly under the load, and to lift the remaining area too.
I think you'd want to monitor the lift as it's going on with survey instruments. Might be a good one to hire an engineering firm to consult on. there's a little more at stake than a backyard patio or driveway. This is worth some damn good $$$$.
If you can't fix it with a hammer....you've got an electrical problem.
I did not ask to many questions as he was not in a hurry to get this done and I would rather look at a project over having someone explain it to me. But I think it is a prestressed slab that has been moved in and something put on top of it. I am sure it is outside hope he can wait till Spring.
The mud would have to spread out to the 10'x 30' area to get that 2.3psi lift. A space under the slab would help to get the mud to spread out. If the mud only spreads out 10'x10' then thats 100sq ft x 144 = 14,400 sq inches / 50,000lb = 3.2 psi It should work, on paper no problem. You'd have to have a good mix of mud. Start out thin to get it spreading out then thicken it up to get some lift.
How heavy is to heavy
Posted - 02/05/2010 : 22:53:42
