concrete pillar footings for pole barn 1

Building 24 x 48 pole barn in area with high water table. Using 12" dia x 4' "Quiktube" forms. When hole is dug begins to fill with water quickly. First 2' sand then brown clay. Thought about wrapping forms in heavy poly bag to keep dry, but can not get form in place and backfilled before ground water interferes with backfill (essentially making mud). Beyond waiting till the rains stop and water table drops... does anyone have a working solution?

 

[Ron]

Go ahead and let form fill with water. Order concrete with higher strength than needed (say 4000 psi instead of 3000 psi). Use smaller than typical aggregate size (1/2-inch max. size)so that you can use tremie or pipe.

Use tremie or similar device to cause concrete to be deposited at bottom of form, not dropped in from top. You can simply use a large diameter PVC pipe (4-inch diameter is sufficient if small aggregate used) if nothing else available.

If you place the concrete such that it starts deposition at the bottom of the form and you keep the tip of your tremie or pipe lower than the rising surface of the concrete, it will displace the water in the form and push it out the top with little detrimental effect on the concrete remaining in the pier form.

 

[jheidt2543]

Has anyone checked the bearing capacity of the soil and was it checked in the wet or dry season?

Here are some suggestions assuming soil bearing is OK:

1. Set the tube form, brace it in place and backfill with "bankrun" gravel or crushed stone 2-3 feet thick around the form. Pour ASAP.

2. Same as above, but set a small "trash pump" inside the tube form to pump out the water. You can carry this from hole to hole to set the forms and backfill. Pour the concrete ASAP after the form is set, with as much water out of the hole as possible. Concrete can be poured under water, if "tremied" (poured through an "elephant trunk&quot or in your case only 3-4 feet deep.

3. Dewatering of the site is a costly option, especially for a pole building with footings only 3-4 feet deep.