Lift plan for a large cantilevered steel section

[LeonhardEuler]

All,

I need help with something that may end up being quite simple, but haven't quite found a solid answer yet.

I am working on a lift plan for a large cantilevered steel section. At the base of this cantilevered section there is a wide flange beam framing into a wide flange column. The column is existing and the beam is new. The beam will have fully welded flanges with a shear tab at the web. I am trying to work up an erection aid to keep the beam aligned during erection so that it can be welded in the correct location. I need a temporary connection detail that will "clamp" the beam in place to allow for surveying to be completed and the beam to be adjusted as necessary according to the survey and then welded in that location. I was going to provide stiffened seat connections on top and bottom and provide long slotted holes in the direction that movement will be need (in the torsional direction for lack of better words). However, I have run into the obvious road block with this that there is not access to weld the flanges if I do this because the angle seats will be in the way.

My current running idea is to provide a bolted angle connection at top and bottom flanges with long slotted holes in the direction of adjustment, but instead of an angle seat running full width of the beam provide (2) angle seats on each flange, so one angle can be removed and replaced with weld at a time.

For bonus points I have some columns that go from level to level (not from floor to level) and need to be attached to a beam above (the beam in question) and a beam below (an existing beam). Is there a typical connection aid for this that anyone knows of where I can pin the top plate of the column and freely move the bottom. It may help to mention that the column is connected with a bolted base plate on top and bottom.

 

[JAE]

A sketch might help everyone visualize your situation better.

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[LeonhardEuler]

 

[LeonhardEuler]

It’s basically a connection experiencing torsion that needs to be clamped from twisting during the crane lift, so that flange welds can be completed.

 

[BAretired]

A wide flange beam is not a good section to resist torsion. What is the purpose of the cantilevered assembly? Have you checked the beam for torsion?

BA

 

[LeonhardEuler]

It won’t have much torsion at final assembly. It has a diagonal extending from end of cantilever structure to 100 inches below the base. This setup is really just to control position during the crane lift.

 

[LeonhardEuler]

By the way the cantilevered structure and beam are all flying up as one piece

 

[Lomarandil]

Rather than an aid at the connection, can you just run the whipline of the crane to a temporary outrigger and allow the crane to adjust rotation at the direction of survey?

----
The name is a long story -- just call me Lo.

 

[SAIL3]

it is really not clear to me what you are attempting to do here....are you finally welding the bm to the col web and if so why?....are the top clip angles initially welded to the web of the col and ,if yes, it would make it difficult to get the bm in there....how is the problem of torsion(any torsion) being addressed in the bm....