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Foundation compaction
I need to dig a hole for my foundation and fill/compact it with ??? for a foundation. The hole will be 40 by 100 and four foot deep. I do not know what material to use and how to go about the compaction. Any help would be appreciated.
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Foundation compaction
There are too many unknowns for a direct answer, such as what's under there, the structure's purpose and construction, and state/local building codes. You might talk with a local contractor or an owner of a similar structure.
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Foundation compaction
Auer's right but I'd like to add you should talk to a local building department official and a civil engineer or archiitect familar with your situation/conditions.
Generally speaking, you need to use a compactor to compact in what are called lifts---usually 3-4" thick layers of fill. BUT it depends on what type of fill you are using, moisture content, etc., etc. The four types of compactors are vibratory roller, plate-type, jumping jack, sheep's foot. Generally you cannot use one type of compactor for all conditions. There is another type used for trenches and that is a about a 4 - 6' wand with pressurized water which is injected into the area. Water displaces the air pockets and as the water drains away gravity pulls the soil down resulting in compaction. Nice to keep in mind when digging and refilling trenches since dirt tends to expand by 30% when uncompacted.
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Foundation compaction
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I need to dig a hole for my foundation and fill/compact it with ??? for a foundation. The hole will be 40 by 100 and four foot deep.
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Well, first off, you don't need to dig a hole nearly that size, normally you would just dig a trench where you want the walls to go and pour a footing (depending on building size and soil conditions) 12" - 36" wide and then build walls on top of that.
For example, if you dug a 4' deep hole 48' x 108' (to allow for working space) you would have nearly 800 yards of fill, that would be enough to fill 80 standard dump trucks.
If however you only dug a 4' wide trench for a 40' x 100' (280 lineal feet) footing and wall, it would only generate about 40 yards of material, that would only fill about 4 dump trucks.
Do you have a need for 76 dump extra truck loads of dirt somewhere? 
After you pour the footing and perimeter wall, you just pour a floating slab right on top of the existing soil unless there is bad soil conditions.
Best of luck.
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Foundation compaction
My site is on a farm and the soil engineer has filed a report requiring me to remove the soil due to the organic material contained in it. I am putting in a slab foundation and that may be the reason she is requiring me remove and replace the entire house footprint of 40x100 amd she says the organic material was found down to four feet. I calculate 1,777 cu yds. I can dispose of the dirt on my property because I have 27 acres. What should I use to replace it to get compaction required for a foundation.
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Foundation compaction
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I need to dig a hole for my foundation and fill/compact it with ??? for a foundation. The hole will be 40 by 100 and four foot deep.
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[QUOTE=HighHopes;173912] My site is on a farm and the soil engineer has filed a report requiring me to remove the soil due to the organic material contained in it.
I am putting in a slab foundation and that may be the reason she is requiring me remove and replace the entire house footprint of 40x100 amd she says the organic material was found down to four feet.
I calculate 1,777 cu yds. I can dispose of the dirt on my property because I have 27 acres. What should I use to replace it to get compaction required for a foundation. [/QUOTE]
Well, as for the first & second paragraph, the engineer is (IMHO sort of) right, you can't support a building on organic material. However, she should also have told you that all you need to do is support the building on a narrow foundation that goes down past the organics to undisturbed soil, then make a floating slab floor that will sit on top of the organics just fine.
As for the third paragraph, you're math is a little off, a cubic yard is 3'x3'x3', or 27 cubic feet. So, 1,777 cu. yards multiplied by 27 is 47,979 cubic feet. If you divide that by 4,000 (40' x 100') you get 12'. I don't think you want a hole 12' deep. I think you missed one "dive by 3" in your equation, it should be 4' deep, not 3 times that or 12' deep.
As for the refilling question, you should be using a good, silt-free, subsoil, or 'B' granular, but I still say, unless you have a real need for soil somewhere, and a source of cheap (and I mean realllly cheap) fill, don't build this way, it will cost you a big bundle of cash mare than is required.
Best of luck.
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Foundation compaction
Whoops! I did miss the divide by three and should only require 582 cu yards. I am stuck with this method of building because of the cost and time required to make a change. I have $55,000 invested in the plans, engineering, and permits. The permit process took two years and I have extended the permit for two years. Now at the end of a four year wait I want to get started on a shoestring budget.
I would like to use soil from my property for the compaction. I have an area where I can get the deep clean soil. Any thoughts?
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Foundation compaction
What's the structure for? Doesn't sound like a residence but if it is, I'm not sure about a floating slab. If it's a utility building, what kind of floor?
If you or your neighbors have stone piles, you can toss big rocks on the bottom and add progressively smaller ones.
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Foundation compaction
The foundation is for a 4400 sq ft house with a slab floor. We do not have access to stones. I can get soil that is free of organic material on my property. I will be looking into a change in the plans that would allow for a "structural" slab.
I will check with my structural engineer and my soils engineer.
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Foundation compaction
Ok, first off, your math is still wrong. If you need to dig down 4' to remove organics, then refill it with "engineered fill", fresh soil which has been compacted in layers (called lifts) of (based on your soil) generally 4" at a time, you will need a hole probably 10' bigger in both directions that the building, so 50' x 110' x 4' deep or 22,000 cubic feet. There is 27 cubic feet (3'x'3x3') in a cubic yard. So, 22,000 / 27 = 815 yards of material.
As long as the soil meets with approval of the Engineer who has to sign off on the job, i.e. free of silt, organics, etc., it doesn't matter where it comes from.
Best of luck.
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