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Sonotube Problem

Sonotube Problem

Sonotube Problem

(OP)
I trying to get clear direction on how to solve a sonotube problem.

I have a 12" diameter sonotube 2'6" tall (2" will be buried).
3" CLR with a W4x4 welded wire fabric.
The sonotube will be resisting a W6x16 with 9000lbs

I have assumed the following:

weight of soil =120lb/ft^3
weight of concrete = 150 lb/ft^3
allowable bearing capacity = 3000 lb/ft^2
f'c = 3000psi

Is the sonotube strong enough to support the load?
I do pipeline work so this is a little different. Any help is appreciated!
Thanks in advance!

RE: Sonotube Problem

I'm sure it's a type but I hope you aren't planning on embedding the sonotube 2". You won't get any replies whether or not the sonotube can support the load. You will have to analyze that yourself. I believe the IBC has a section in chapter 18 for embedded posts. I also wouldn't assume an allowable bearing capacity. You will need a geotech to provide that information.

RE: Sonotube Problem

Lateral loads?
Uplift?
12" diameter Sonotube, 3" clear to WWF means the WWF is rolled into a 6" diameter tube?
Anchor bolts? Are they embedded within the confines of the WWF?

RE: Sonotube Problem

Sonotube is a cardboard form. It can't carry any serious axial load so the answer is sonotube cannot carry a 9,000# load.

If the sonotube is filled with concrete, the axial stress is 9000/113 = 80 psi which is a trivial load for concrete so a concrete filled sonotube can easily carry the load.

If the concrete bears directly on the soil, the bearing pressure will be 11,500 psf which is substantially more than your assumed bearing pressure of 3,000 psf so the soil cannot carry the load.

Perhaps you should try a different approach.

BA

RE: Sonotube Problem

I agree with BA here.

The final concrete filled sonotube column needs to bear on a minimum 2'-0" X 12" thick square spread footing.

Mike McCann
MMC Engineering

RE: Sonotube Problem

Are there no moments on this thing?

You could use a 24" drilled in pier finished with a 12" sonotube formed top.

Michael.
"Science adjusts its views based on what's observed. Faith is the denial of observation so that belief can be preserved." ~ Tim Minchin

RE: Sonotube Problem

Also agree with BA
Sonotube is a cardboard form for circular concrete columns. I wouldn't design or use it for anything else but that.

RE: Sonotube Problem

What's the winter frost depth at the site? If you have a frost-susceptable soil and real winters, 2 ft is too shallow. Frost may heave your base out of the ground, or turn the soil it is bearing on to mush during spring thaw. Yet another reason to consult a geotech.

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