the allowble deflection for 2.5m cantilever
the allowble deflection for 2.5m cantilever
(OP)
i use safe programe and after i have represented the wall loads as aline loads on the cantilever (2.5 m the thicknesse is 30 cm ) the deflection is 2.2 cm and i don't know is this safe or not?






RE: the allowble deflection for 2.5m cantilever
I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.
RE: the allowble deflection for 2.5m cantilever
RE: the allowble deflection for 2.5m cantilever
I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.
RE: the allowble deflection for 2.5m cantilever
RE: the allowble deflection for 2.5m cantilever
I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.
RE: the allowble deflection for 2.5m cantilever
#2) how many stories of brick will occur above the cantilever? How high is the next relief angle in the brick? 22 mm is probably a bit much if it will cause a horizontal joint beneath a brick support ledge to open up. I'd think that you'd want to keep that under 10 mm at the most.
I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.
RE: the allowble deflection for 2.5m cantilever
RE: the allowble deflection for 2.5m cantilever
RE: the allowble deflection for 2.5m cantilever
RE: the allowble deflection for 2.5m cantilever
Mike McCann, PE, SE (WA)
RE: the allowble deflection for 2.5m cantilever
RE: the allowble deflection for 2.5m cantilever
RE: the allowble deflection for 2.5m cantilever
total deflection - long term including creep shrinkage cracking and tension stiffening effects to L / 125
brittle finishes/masonry partitions - total deflection after addition of finishes etc - L/ 250
Also depends on manufacturers specifications for anything on attached to the slab eg glass curtain walls
For transfer members, depends on support settlement considerations above.
As Hokie said, make sure you know what is being considered in the calculations. Safe gives different deflection calculations depending on designer data. The limits above are for properly calculated long term deflections. NOT short term uncracked.
RE: the allowble deflection for 2.5m cantilever
The problem with concrete is that a load like LL might cause an increase in the SW and SDL deflection!
Then you get creep which is normally considered to be caused by the permanent load which includes some live load, but most of which happens after the SW and most of the SDL is applied.
Then you get shrinkage which is technically not load dependant except that it depends on the amount of reinforcement and the neutral axis depth among other things, and most of which occurs after the SW and SDL are applied.
So which of these deflections are part of LL deflection?
Where does BS code talk about LL deflection (ACI does but the logic of LL deflection comes from elastic member design, and concrete is not elastic and it is about time some design codes figured it out!).
if you are going to deal with real deflection calculations, you need to understand the logic before using computer software to calculate them. There are far too many buildings around the world with deflection problems caused by the lack on understanding of design engineers of real deflection calculations and what they are getting from their software. And you should not be getting your education on this from this website, get a good book on concrete deflection calculation.