Silo bracing
Silo bracing
(OP)
Hi All, see attached photograph
What is the logic of bracing back to the cone on this silo?
We have had some discussions and it seems that it is to limit the unbraced length of the leg in the weak direction?
Any thoughts
What is the logic of bracing back to the cone on this silo?
We have had some discussions and it seems that it is to limit the unbraced length of the leg in the weak direction?
Any thoughts






RE: Silo bracing
RE: Silo bracing
RE: Silo bracing
RE: Silo bracing
Reducing unbraced length would be one motivation. Allowing a moment connection to the silo may be another motivation.
It's kind of hard to tell what the design philosophy is on something like this- you can make different assumptions about what is fixed and what isn't.
I don't care for the little tabs that the cross-bracing is attached to, looks like they should be in line with the bracing.
RE: Silo bracing
The leg columns are bolted in a few rows of bolts so that there is a fair amount of engagement with the silo walls. I think it would be reasonable to say this is a moment connection. Comments?
RE: Silo bracing
I'm not sure the person who designed it could articulate his/her own design intent.
RE: Silo bracing
RE: Silo bracing
RE: Silo bracing
You can assume the legs are fixed to the cylindrical shell. Or that they are fixed at the foundation. Or some of each. In this case, it looks like the legs are cast into the foundation? If you assume either end if fixed, you can wind up trying to support a large moment at that point. If you assume either end is pinned, you have to figure out how to ensure flexibility at that point.
Assuming the cross-bracing on this one isn't pre-stressed in some way, presumably, you'd get compression loading from gravity loads in the cross-bracing?
RE: Silo bracing
RE: Silo bracing
RE: Silo bracing
This kind of radial bracing is very typical from what I've seen in the silo world. Almost every commercial silo I've come across has it. Hence my questions, because it's just not well supported with documented reasoning why it's there, but I can tell you from the way these silos are constructed, if it's not needed you can be sure it's not provided!
JStephen, those references are helpful, thanks. I've been using the Moss approach, which actually doesn't consider the bending moment on the leg in the case of X-braced legs. Bending stress in leg is only considered (in that method) for unbraced legs. I take it Moss kind of assumes that the bracing eliminates the bending. There is interestingly a small note also about "lateral bracing". I assume this to mean the type of bracing as in the first post.
I've included another photo here of the base attachment, it's not a great photo but you can see the implementation.
RE: Silo bracing
RE: Silo bracing
Dik
RE: Silo bracing
I am new into Silos and heard you said 4 books, would you be able to share the name of these books so I can read them
Thank you