Net Uplift on Steel Joist
Net Uplift on Steel Joist
(OP)
When specifying net uplift pressure on steel joist, do any of you indicate design approach (say ASD) or the exact load combination (say 0.6D+W) used to arrive at that value. With SJI promoting both LRFD and ASD for the design of steel joists, isn't it misleading for the joist designer to not have this info. Any thoughts on this??






RE: Net Uplift on Steel Joist
If you have anything more than typical uniform gravity and wind uplift loading, I would recommend creating a table with each load case separately defined and letting the joist manufacturer combine the loads.
RE: Net Uplift on Steel Joist
In Canada it's most confusing when dealing with geotechs or foundation work. That part of the industry is slowly shifting towards working with factored loads, so depending on the company they'll default to different things.
This is really a situation where a few words can save everyone a world of headaches.
RE: Net Uplift on Steel Joist
RE: Net Uplift on Steel Joist
To me, there are just too many places to make a mistake with factored loads, and they are constantly changing.
Mike McCann
MMC Engineering
RE: Net Uplift on Steel Joist
"Net uplift pressures on roof joists as indicated in the drawings is based on 0.6D+W load combination"
RE: Net Uplift on Steel Joist
Serviceability controls most of my designs anyway so why should I do the extra work?
RE: Net Uplift on Steel Joist
RE: Net Uplift on Steel Joist
Strucguy...yes, let 'em know your premise.
RE: Net Uplift on Steel Joist
RE: Net Uplift on Steel Joist
I'll still be prepared to submit calcs in LRFD to demonstrate that I am "competent" but for my own use it's back to ASD. Except for concrete, again, as Excel noted.
RE: Net Uplift on Steel Joist
RE: Net Uplift on Steel Joist