Down on the farm we have a high water table in places. What is done when you dig down 36″, the frost line, and the bottom of your footing hole fills with 6″ of water.
I know what they do on the Mississippi river.
I am planning piers, footings and light weight structures.
If piers are impractical, how do poles hold up?
Replies
go a foot deeper and add a foot of rock. pour on top of that.
What if I hit solid rock before I get a foot deeper?
How long should I let a footing cure in a 70+ degree environment?
What kind of rock? Misc rubble from around the farm, we got lots, or the gravel used to make the concrete?
Edited 11/7/2004 1:28 pm ET by FarmerDave
Not to offer advice.... My first construction job, a hundred years ago, was 11 acres of apartments in Denver. Pier construction to avoid the bentonite. Often the drill would hit water.
We were told to be looking for work if we mentioned it to the engineer and go ahead and drop as much concrete as we could into the standing water. Got pretty soupy. Sometimes it was a whole lot of concrete, sometimes very little. No telling what strength they ended up with, but the apartments were still standing last time I looked.
PAHS Designer/Builder- Bury it!
What kind of soil are you dealing with?
For the really bad problem areas, helical piers have a pretty good track record.
DRC
>What kind of soil are you dealing with?
The soil and water conservation district calls it gravelly overflow. It's mostly gravel or rock proper with clay filling between the aggregates. The rocks are real hard. Old timer neighbor says it will wear out plow points in a hurry.
Digging post holes by hand usually requires a 17 pound bar. The neighbor and his tractor mounted Danuser post hole digger usually make short work of the situation.
Sounds to me like if you can dewater the excavation long enough to place concrete you shouldn't have any problem at all. That sounds like nearly ideal soil for bearing a load.
I've also heard of concrete mixes designed specifically for placing in water, but I don't have any details on that.