HSS Col Splice

[SAIL3]

attached is a concept for installing an equipment platform inside an existing warehouse that has an existing conc slab and limited headroom...the upper portion will be shop assembled...the lower portion consists of (4) loose cols......using (2) cranes the upper portion of platform w/equip is lifted and held in place while the (4) lower cols are positioned in place....the platform is then lowered to within 1/2" of field splice and held in place while the (4) field bolts are installed and cols aligned and bolts tightened...then whole assembley is lowered the remaining 1/2" and cols are welded to pre-installed base plates on conc slab...then plates @ field are welded together ...then cranes are removed....
my main concern right now is the safety of the workers as they install, align and tighten the bolts @ the field splice and also positioning the (4) loose cols into place under a suspended load....is anyone aware of OSHA requirements for safety while working under a suspended load?....I would also welcome any ideas or improvements on how to accomplish this...thanks for your help

 

[BAretired]

I don't think OSHA would take too kindly to men working under a suspended load. I would prefer to see the lower columns braced first, then the load lifted up and placed on top.

BA

 

[SAIL3]

BA...instinctively, I have the same opinion about this....my primary aim with this concept of having the (4) lower cols loose was for field adjustment so the segments of each cols could be ligned-up....if I provide temp braceing for the lower (4) cols it would basically fix the location of these cols...using 2 cranes while lowering the upper portion onto these (4) fixed points which, in turn, would have (4) bolt holes that would have also to lign-up would seem to me very difficult to achieve......I am trying to come up with some guidance system while lowering the upper portion that would result in the col segments and bolt holes ligning up.....also, I suspect that there is alot of field work performed while structural parts are joined together in the field, but, not sure about this and to what extent OSHA requirements apply in these situations