6 ton crane on 6" thick concrete slab safe
6 ton crane on 6" thick concrete slab safe
(OP)
I recently assigned to a project to design a steel structure for a 6 ton overhead crane and i am very uncomfortable that my lead design engineer suggested to install the crane on a 6" thick concrete slab. The ground floor slab (f'c=3700 psi) is rated for 600 psf and I recommended to install a pile foundation. my question is, would it be safe to install a 6 ton crane on 6 inch thick slab.






RE: 6 ton crane on 6" thick concrete slab safe
I have no answer for my question, but I think you know the answer for your question.
Mike Halloran
Pembroke Pines, FL, USA
RE: 6 ton crane on 6" thick concrete slab safe
I would also think the punching shear would fail as well...unless you have a 4 ft. square base plate or something.
RE: 6 ton crane on 6" thick concrete slab safe
I am assuming this is a portal framed building with steel columns onto a slab.
would you require piles, what about large concrete footings, what is your hd like.
or is this a jib crane.
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RE: 6 ton crane on 6" thick concrete slab safe
Is it a 10ft span crane?
Is it a 100 ft span crane?
Double girder?
Kit type crane?
A six ton crane could have wheel loads of 25 kips or 5 kips and foundation reactions that are somewhat proportional.
RE: 6 ton crane on 6" thick concrete slab safe
Dik
RE: 6 ton crane on 6" thick concrete slab safe
I will note that we have successfully put light capacity crane systems on existing 6" concrete slabs. Large column base plates help. Insureing adequate subgrade modulous contributes as well. I assume you are planning on the crane columns being braced to to an existing building structure. A 6" Slab cannot take much in the way of moment loads
RE: 6 ton crane on 6" thick concrete slab safe
ZCP
www.phoenix-engineer.com
RE: 6 ton crane on 6" thick concrete slab safe
First, figure out what the TOTAL crane weight is (plus overload and margins are), NOT what load the crane can lift or what its capacity is at some lift radius.
A six-ton crane could be a truck-portable four wheel road rig on four 2 ft x 2ft steel pads while lifting a 6 ton load (12,000 lbs alone) at 100 feet radius - total weight on the concrete might be upwards of 50,000 - 80,000 lbs. (And what happens when that crane isn't available, and the contractor brings in the "next biggest" crane that weighs 100,000 lbs?)
Or it could be a rail-mounted overhead jib boom whose load is carried to the structural steel already in position.