Pulling Iron

[PEinVA]

We have a transformer vault room that requires some pulling irons to be embedded in the concrete to resist 6,000 lbs in tension.

These appear to be U shaped rebar/rods that will embed to the concrete and tie to the reinforcing steel. How should I treat this load? It occurs only 8" from the foundation wall on 3 sides, and the slab thickness is 15".

I'm not worried about the slab with this load (as it is something the power authority just came up with) but how should I plan on detailing this?

Thanks!
RC

RC
All that is necessary for the triumph of evil is that good men do nothing.
Edmund Burke

 

[kslee1000]

Check with PCI for design/details on embedded lifting devices. Make sure proper safety factors are incorporated. The devices could fail and kill/injure someone.

 

[slickdeals]

If the slab is already placed, then it might be difficult. If the slab is not placed, then embedding them should not be a problem. You will need to apply this as a concentrated load on the slab. Provide reinforcing steel in both directions around this load to distribute it into the slab.

 

[PEinVA]

Thanks for the suggestions kslee1000 and slickdeals.

The pulling irons are not to be used to hang/lift anything they are there to allow the unit to be moved around the floor. They are on the floor of the unit, and I don't really understand how we are to get 6000 lbs in tension on them in this capacity, but whatever.

I will look into PCI for embedded lifting devices.

The 15" slab is already heavily reinforced and we are planning on adding reinforcing around the irons, as it has not been poured yet.

Thanks.

RC

RC
All that is necessary for the triumph of evil is that good men do nothing.
Edmund Burke

 

[civilperson]

A come-along will be hooked to the pulling irons and used to move either the transformer or pull the power cable. An omega shaped bend with the two ears embedded in the concrete under the first layer of reinforcement is a standard shape for electrical vaults.

 

[kslee1000]

RCraine:

It is commen on substation to have such device to pull/slide the transformer for service or replacement. These device is usually permenent with pull post/pulley/motor. for smaller one's, a truck can do the trick. Anyway, it happened before that either the lift ring been sheared, or the device been pull out of the concrete, image what the flexible pulling cable would behave with hook attached, it flew in random manner with killing forces. So, just a friendly reminder, either case - lift or pull, needs hefty margin of safety, and designd with cautious.