Grain Storage Bin Foundation Literature 3

[a8d2b]

Does anyone have any good reference material for grain bin storage foundations? I want to determine the vertical/lateral force distribution transferred to the footing by a corrugated ring connection with anchor rods to the foundation. After an extensive internet search I was troubled to find very little.

 

[MiketheEngineer]

Some of the AG departments of various universities have studied this. Might look there. Seems like Missouri and Wisconsin come to mind.

Yes - I too have problems finding anything that was really good.

I treat it like water and/or dirt - just a different density.

 

[aeoliantexan]

Pressure measurements in silos have shown that much of the grain weight is transferred to the sidewalls by arching and friction, such that after the grain height exceeds about 2 or 3 times the diameter, the pressure at the center of the floor no longer increases. As a result, both the vertical load and the hoop stress in the walls can be much higher than expected. The effect is exacerbated when the silo is being unloaded from the bottom.

Tschebotarioff discusses this on Page 388 of his book "Foundations, Retaining and Earth Structures", McGraw-Hill, 1973. He references an article by Jamieson in Engineering News, 1904.

Modern bins are usually much wider than the old skinny silos, so the effect may be less.

Find a structural engineer who designs grain storage structures and consult with him. There is a lot of art involved, and many mistakes have been made over the years.

 

[BigH]

The issue of silo effects has been discussed many times on the various geo forums - do a search and you will find some.

 

[a8d2b]

I realize that there has been much discussion on the topic. However, I specifically was looking for guidance on the load distribution to foundations. There is very little if any discussion on this specifically.

 

[FixedEarth]

The most common foundation we use for silos in CA are a Mat foundation (18" to 30" thick) for low heights and a Mat foundation supported by drilled piers on the taller silos.

For the anchor bolt design you can use Appendix D of ACI 318 & Anchor Selector Software. For the Mat foundation on ground, after checking for shear and moment capacity, most of the time, 0.0033bd steel area is sufficient. Seismic overturning plays a role here locally and so drilled piers can't be avoided. You will need to ask the geotechnical firm for vertical, uplift and lateral capacity. Then design the pier as a column.