Steel beam to lift 12,000 pounds-size??

[pappa]

I have a leaning 6 ft wide chimney that weighs approxi- mately 12,000 pounds. I would like to insert a steel beam of about 14 ft length under it, so that 4 ft stick out each side. Then I will use two 10 ton jacks to lift the beam&chimney. I plan to position the jacks 3 ft from the chimney. I need to know what size/shape/material steel I-beam (or other shape?) to use that will support this weight over a 12 ft span with minimal deflection. I wish achieve an even loading across the foundation to lessen the chance of cracking it, so minimal deflection is needed.
I do not know where to find this information, even though I did have "statics" and "dynamics" in school. (I am an electrical engineer). If someone could clue me in as to what I need, I will greatly appreciate it. Also, I am interested in the learning the information source, so I will be better informed in the future.
I am fixing up an old farmhouse, so who knows what I might need down the road. Thanks!

 

[austim]

Hi, pappa.

What you really need is an experienced structural engineer, who will fully assess your scheme.

We cannot tell you what damage you may do to your chimney when you try to take its full weight on two local points; you cannot achieve "equal loading" on any foundation if you load it at only two points; we cannot tell whether the foundation will do much more than simply "crack" - you could do quite cause serious damage to it, and end up with much worse problem than the existing lean; we cannot tell why your chimney is leaning at present - it could well be that your foundation is quite inadequate right now, and you are addressing a symptom rather than the real problem.

"Minimal deflection" is a meaningless design criterion. For some purposes, span/150 may be quite OK, for others, one fifth of that might be needed.

As for references, all that you would need would be a couple of good steel design texts, several geotechnical texts, a lab report on the soil conditions under your foundation. (And a couple of good concrete texts if it is a concrete chimney). Plus some books on site construction operations, and several years of worthwhile experience in the field.

As far as your basic site operation is concerned - if you try to lift a chimney with only two jacks, it will almost certainly fall over perpendicular to your proposed lifting beam unless it is also guyed in both directions, and the guys are extended as you lift.