50% live load reduction factor ?
50% live load reduction factor ?
(OP)
Hi again,
For that 30 story building, the negineer has used a 50% live load reduction. The National Building Code of Canada has a formula to calculate this reduction factor and the reduction I calculate comes to 78%......
Is there some empirical design formula that I may be missing here ??
Thanks
For that 30 story building, the negineer has used a 50% live load reduction. The National Building Code of Canada has a formula to calculate this reduction factor and the reduction I calculate comes to 78%......
Is there some empirical design formula that I may be missing here ??
Thanks






RE: 50% live load reduction factor ?
50 years ago the allowance for simultaneous live load distribution was treated much simpler. I think the Loading Code was a small 30 page handout.
Johnp.Rz
http://www.mets.net.au
RE: 50% live load reduction factor ?
RE: 50% live load reduction factor ?
Away from that, I have never know of a reduction that great.
If it is concrete, I hope the contractor is ready to shore the building to grade for most of its duration...
Daniel Toon
RE: 50% live load reduction factor ?
RE: 50% live load reduction factor ?
Australia; AS/NZS1170.1:2002; LLRF = 0.5 (min.) for supported area > 225 m2 (not applicable for certain load types). The formula given is virtually identical to "0.3+(9.8/B)^.5" as pasted by Calculor, but with the 0.5 limit.
UK; BS6399:Part 1:1996; reduction in live load = 50% (max.) for columns etc. supporting > 10 no. floors.
RE: 50% live load reduction factor ?
This reduction is not to be applied to loading on beams.
Another reduction factor of up to 25% can be used for live load on beams depending on the area of floor that the beam supports.
RE: 50% live load reduction factor ?
By "columns etc" I meant the elements as listed in Clause 6.2; "columns, piers, walls and their supports and foundations".
From a theoretical viewpoint it could be argued that transfer beams can be included if they support columns carrying a number of floors. Common practice may indicate otherwise.
The above is based on the 1996 edition, please ignore if it has been amended since.