helical piles

[Amanda_931]

I've seen something like this before, although not mentioned by treehugger (which wasn't around then) as helping to reduce the amount of concrete used in building where people really didn't plan for concrete walls. Rather something that would help me build on the fill dirt my trailer is sitting on.

http://www.treehugger.com/files/2006/11/helical_piles_a.php

It has a helical base of different dimensions, depending on bearing capacity needed; they bring in a little robotic machine (the R2Dpost) and just screw it into the ground. The surface is barely touched, a plastic jacket protects it from frost, and you have an instant foundation. When it is time to turn the land back to nature, you just do it in reverse and unscrew the foundation from the ground. Also effective for holdbacks and tiedowns where usually concrete is poured. What a great way to reduce our impact on the earth, get a solid foundation and idle one more concrete truck.

And from the company website.

http://www.technometalpostontario.ca/about/features/features.php?lang=en

No digging necessary
Guaranteed against frost heaving
Competitive pricing
Technical support available
No damage to the landscape
The posts can be relocated
Bearing capacity of posts approved by Professional Engineers
No delay, construction begins as soon as posts are installed
Can be installed under existing structures
Ideal for rough and restricted areas
Installation equipment adapted for any structure
Can be installed below the water table
Most importantly, we have the solution to your difficult and hazardous work

[Sassy]

Those look rather simple & effective for supporting a foundation - I didn't download the PDF so don't really know what the R2Dpost robotic machine is that places the helical posts... wonder if the system is really expensive...

[glenn kangiser]

I was attracted to the subject you posted thinking that this was some new --unknown to me -- medical affliction that I should make myself aware of------ :-/

but now I see that it is the screwed in anchors we used on a remodel of an old church to make it into an office building.  

The GC on the job was a bit of a self righteous know it all and installed them in the wrong place but after I told him I couldn't connect to them there and he moved them he finally got it right.  Many of his associates were drug abusers - I assume he was too.  The installation machine attached to a Bobcat and automatically screwed them into the proper torque then clicked to indicate time to stop.

[John Raabe]

Interesting! The PDF deals with electrical techniques for controlling corrosion - a bit over my head.

However, the basic item is shown in this simple diagram



It's a big load bearing screw. Digs itself into the ground (presumably below frost level) and spreads out the point load into the underlying soil. Neat! When you're done or want the foundation somewhere else just unscrew it!

See the Little Yellow Machine put in the pretty Green foundation for an addition.

[Daddymem]

Looks like a screw pile variation.  They use them around here for mucky soils like lighthouses are built on and very large versions for smaller buildings in Boston.  Neat.

[Amanda_931]

Yes.  And some other brand (from some google ad I think) can also be used to hold retaining walls with a good chunk of fill behind them.

If you can get to the down side of the wall, anyway.