Grain Silo Structural Analysis

[DerekG]

Looking for guidance on checking the structural integrity of existing steel and concrete empty/abandoned grain silo structures for proposed wind loads (antennas).

 

[ishvaaag]

Since the silo use is gone you merely need to seek the hardpoints in the structure able to take your loads (or if necessary reinforce the structures) and then check according the actual and final state of the same with the antennas in place. You will be asked to follow then some mandatory code, but as a start the ACI 318 and AISC LRFD codes could be used.

 

[RMPE]

Have a list of references for silo analysis if interested, but as ishvaaag implied, sounds you'll be getting in too deep for whats necessary. FYI, ACI-313 on silo design is available in the MCP.

 

I too am looking for some material to calculate the wall thickness for silo design. Have used Jasen's equation but needed a second referance for cross check. Kindly suggest overload factors for replication of forces in dynamic state (i.e. during loading and unloading).
Thankyou

 

[Imagineer]

RMPE,
Could you post those references. I have been looking for silo design books. Imagineer

 

[RMPE]

Reviewed some steel bins and cocnrete silos recently. Steel bins were for loading evaluation only. The concrete silos was an interesting project. They were built for cement storage, then abandoned and an industrial facility moved on site and wanted to use them for water storage. Unfortunately they were only single layer reinforcing and all tied together so there was no economical way to strengthen them and of course liquid storage with durability load factors was a large increase in loading.

I simply did a search for books and found the following:

of course ACI 313
"Design of steel bins for storage of bulk solids", Gaylord and Gaylord
"Circular storage tanks and silos", Ghali
"Design and construction of silos and bunkers", Safarian & Harris

 

[Tankman650]

Another useful book,
"Useful Information on the Design of Steel Bins and Silos" is available from Steel Plate Fabricators Association

http://www.spfa.org

for $25. Very useful and inexpensive.

HTH

Tankman

 

[DerekG]

I have resolved the issue of mounting to a silo. Now I have to determine the structure's capacity to resist wind when empty. In particular, the silos I am looking at are precast concrete stave silos with exterior hoop steel reinforcing. Their diameters are between 20 and 30 feet with heights around 60 feet. Wall thickness about 2.5 inches. Unanchored, gravity structures. I have reviewed ACI 313 but I am still searching for a more detailed resource.

RMPE,

Does "Design and construction of silos and bunkers", Safarian & Harris, contain design information on concrete stave silos.

 

[RMPE]

Yes, in Chap 8. I copied the index but borrowed the book from a university library as needed.

 

[redhead]

Now out of print, but the original "bible" on silo design was by Milo S. Ketchum.

 

[DerekG]

RMPE,
Thanks for the reference. I am trying to find it locally.

redhead,
The only thing I can find is the "Structural engineers' handbook; data for the design and construction of steel bridges and buildings..." Is this the "bible" you referred too.

Thanks again.