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RE: Auger Cast Piles

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There are several drillers for auger cast piles that are very good at what
they do.  Unfortunately there are several drillers that don't have a clue.
A good specification is vital.  Find out who the bad ones are and predicate
the required experience to preclude them.

The smallest that most drillers can do and reinforce at all is a 14".  Piles
can be post-tensioned.  Smaller piles can be reinforced with a single rebar
in the center of the shaft.  If I am putting in a cage, I like to use a 24"
augered pile.

This is the DFI web site:
http://www.dfi.org/

For a specification:
http://www.hnd.usace.army.mil/techinfo/cegs/cegstoc.htm  and go to 02465

This is Berkel's web site (about the best there is, Charlie Berkel was one
of the inventors when he was with Intrusion):
http://www.berkelandcompany.com/

For NDT testing:
http://www.olsonengineering.com/

A critical point:
You are not pumping concrete in the hole.  It is grout.  Slump is
irrelevant.  You measure flow rate through a flow cone.

I have designed heavily reinforced piles in Los Angeles to a depth of 45
feet.  Once the original driller was fired, the job went very well.  

In other applications, I have designed them to a depth of 65 feet with full
reinforcement cages.  I have done single rebar reinforced piles to a depth
of 90 feet.  I have designed low headroom auger cast piles as deep as 70
feet inside a facility with 12 ft roof height.  

The cover is maintained by using a "bird cage" centralizer or snap on
plastic spacers.  Maintaining the cover is the same issue for slurried
caissons.

Regards,
Harold Sprague


> -----Original Message-----
> From:	George Richards, P.E. [SMTP:george(--nospam--at)BORM.com]
> Sent:	Friday, September 01, 2000 10:46 AM
> To:	'seaint(--nospam--at)seaint.org'
> Subject:	RE: Auger Cast Piles
> 
> If I may ask a second set of questions.  How do we get a gage of steel
> down
> into a hole that has already been filled with concrete?  Then when the
> cage
> is in how do you know you maintained 3 or 4 inches clear to soil?  How
> deep
> can one drill to?  
> 
> Thank you.  George Richards, P. E.
> 
> -----Original Message-----
> From: James Hagensen [mailto:JHAGENSEN(--nospam--at)HNTB.com]
> Sent: Thursday, August 31, 2000 9:54 AM
> To: 'seaint(--nospam--at)seaint.org'
> Subject: RE: Auger Cast Piles
> 
> 
> We have never used augercast piles smaller than 14". A better size and the
> size we have used the most is 18".  This size worked best since we used
> the
> piles in seismic zone 3 and had lateral loads in the piles.  (At 14"
> diameter you can' get much of a cage in the top of the pile allowing for
> 3"
> clear around the cage.)  Bending moments and ductility requirements in the
> upper portions of the pile greatly effected and often controlled the
> design.
> 
> 
> Jim Hagensen, SE
> 


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