Return to index: [Subject] [Thread] [Date] [Author]

RE: Auger Cast Piles

[Subject Prev][Subject Next][Thread Prev][Thread Next]
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

-----Original Message-----
From: Jim Kestner [mailto:jkestner(--nospam--at)somervilleinc.com]
Sent: Thursday, August 31, 2000 8:07 AM
To: seaint(--nospam--at)seaint.org
Subject: Re: Auger Cast Piles


I believe augercast piling are generally 8 to 14" in diameter. They are
drilled with a continuous hollow stem auger and grout is injected thru
the stem under pressure as the auger is withdrawn. They are typically
used as friction piles and are installed in groups with a pile cap to
distribute load. The hole cannot be inspected during installation, like
a caisson.

Drilled piers or caissons are generally 12" to 48" in diameter, but I
have heard of some up to 11'-0" in diameter (John Hancock Building
Chicago). They can be straight shaft or belled at the bottom with a
special tool. They are typically end bearing and are normally installed
as a single load bearing element. The hole is drilled sometimes with a
steel casing to prevent caving. An inspector can be lowered in the hole
(30" or larger) to inpect the bearing condition before the concrete is
poured. The casing is usually recovered after the concrete is poured (if
they are lucky).

I hope this helps.

Jim Kestner, P.E.
Green Bay, Wi.



******* ****** ******* ******** ******* ******* ******* *** 
*   Read list FAQ at: http://www.seaint.org/list_FAQ.asp 
*   This email was sent to you via Structural Engineers 
*   Association of Southern California (SEAOSC) server. To 
*   subscribe (no fee) to the list, send email to 
*   admin(--nospam--at)seaint.org and in the body of the message type 
*   "join seaint" (no quotes). To Unsubscribe, send email 
*   to admin(--nospam--at)seaint.org and in the body of the message 
*   type "leave seaint" (no quotes). For questions, send 
*   email to seaint-ad(--nospam--at)seaint.org. Remember, any email you 
*   send to the list is public domain and may be re-posted 
*   without your permission. Make sure you visit our web 
*   site at: http://www.seaint.org 
******* ****** ****** ****** ******* ****** ****** ********

******* ****** ******* ******** ******* ******* ******* *** 
*   Read list FAQ at: http://www.seaint.org/list_FAQ.asp 
*   This email was sent to you via Structural Engineers 
*   Association of Southern California (SEAOSC) server. To 
*   subscribe (no fee) to the list, send email to 
*   admin(--nospam--at)seaint.org and in the body of the message type 
*   "join seaint" (no quotes). To Unsubscribe, send email 
*   to admin(--nospam--at)seaint.org and in the body of the message 
*   type "leave seaint" (no quotes). For questions, send 
*   email to seaint-ad(--nospam--at)seaint.org. Remember, any email you 
*   send to the list is public domain and may be re-posted 
*   without your permission. Make sure you visit our web 
*   site at: http://www.seaint.org 
******* ****** ****** ****** ******* ****** ****** ********