huangyhg

temporary w8x15 connection to hss 12x4
question:
california highschool remodel:
i need to design an attachment of a temporary safety beam (w8x15) between two hss 12x4 (flat side)columns for elevator installation. i was thinking of using a wt at each end to bolt into the web of the wide flange. after elevator installation, the saftey beam and the wt have to be removed to attach the elevator guide rails.
note: the back of hss columns will be framed into existing wall. saftey beam is temporary and has to be removed because of insufficient height clearance in existing structure.
my question: any suggestions on how to attach the wt to the hss column without going through the hss column with a bolt? since this is a temporary installation, i want to avoid welding. remember, i have to deal with dsa approval...

maybe a hollo-bolt from lindapter? (google it) never used them myself, but they look like an interesting solution to problems such as the one you describe.
why not field weld a single plate connection to the face of the hss and bolt the w8 to the plate? be sure to check the hss wall for the load.
pmr06: yeah i had seen the hollo-bolt. however it does not have an esr report so i didn't want to use it. dsa project...
twinnell: thanks for the suggestion. i could weld a plate however do i want to do that for a temporary condition where the plate would then have to be removed after elevator installation? i need to use that hss for elevator guide rail support. i'm new at this so i'm not sure if this is done often...
how about an angle seat for the beam? the angle supporting the beam would be clamped to the tube by bolts to an angle on the backside of the tube. the bolts would be on either side of the tube (not thru it).
jike: i'm liking your idea. thank you very much.
pmr06 and twinnell: thanks for your input as well.
jike,
just curious, are you letting friction to do the work? i guess this is a work area and sometimes the vibration from the moving equipments can loosen the bolts.
figglet,
how about, having just one size samller tube to fit snug into the hss, which means the smaller tube will be able to slide in and out. just connect the wide flange to this smaller hss. when done, just slide the system out from the permanent hss. you can have a slidable pin thru both the tubes to provide bearing.
you can try using friction only but like shin25 says, you may need to be concerned about vibration loosening the bolts. perhaps lock washers or jamb nuts would be advisable under those conditions. if you are concerned about the angle sliding down the tube, perhaps you can use a keeper baz welded to the tube.
you can always grind or burn the weld off when the work is done. is that permitted? that's a lot more reliable than friction.
weld and grind as stated by ucfse. the hss sections will be as good as new when painted.
grindig off the weld works as long as you ave access to the weld once you are ready to take it off. depending on your load, you could drill and tap on face of the hss to recieve bolts.

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