Overturning and Sliding FoS
Overturning and Sliding FoS
(OP)
Ok, so looking through this forum and others there seems to be a big debate with people on both sides whether a 1.5 factor of safety needs to be applied to the 0.6DL + WL load case. From my research I have come to the conclusion you do not double them up, with the below linked article stating so in the most easy to understand terminology.
https://risa.com/news/why-dont-i-need-a-1-5-safety...
My question comes in wondering what about when 0.6DL + WL is not your controlling condition?? I have a column that comes down at an angle, so I am finding that my max horizontal force is actually with max gravity and not wind. So do I take the ASCE load case (DL + 3/4LL + 3/4SL) and compare that to 1.5? Or do I go back to the old formulas where everything had a factor of 1 and run that versus the 1.5? More importantly, is there anything anywhere that states this that I could fall back on should it be questioned during peer review? I am fairly sure there is nothing specifically stated in the codes, so I would think it would have to be an article or something in a structural journal/publication.
https://risa.com/news/why-dont-i-need-a-1-5-safety...
My question comes in wondering what about when 0.6DL + WL is not your controlling condition?? I have a column that comes down at an angle, so I am finding that my max horizontal force is actually with max gravity and not wind. So do I take the ASCE load case (DL + 3/4LL + 3/4SL) and compare that to 1.5? Or do I go back to the old formulas where everything had a factor of 1 and run that versus the 1.5? More importantly, is there anything anywhere that states this that I could fall back on should it be questioned during peer review? I am fairly sure there is nothing specifically stated in the codes, so I would think it would have to be an article or something in a structural journal/publication.






RE: Overturning and Sliding FoS
RE: Overturning and Sliding FoS
DaveAtkins
RE: Overturning and Sliding FoS
RE: Overturning and Sliding FoS
Additionally, I have performed some more research and think I have my answer. Looking at section 1605.1.1 in the 2009/2012 IBC it states:
"Regardless of which load combinations are used to design for strength, where overall structure stability (such as stability against overturning, sliding, or buoyancy)is being verified use of the load combinations specified in Section 1605.2 or 1605.3 shall be permitted."
No mention of a 1.5 factor unless you are specifically looking at retaining walls covered in 1807.2.3. So using ASD load combos and you are good as long as you meet a FoS of 1.
RE: Overturning and Sliding FoS
RE: Overturning and Sliding FoS