Need a book? Engineering books recommendations...

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

RE: What would you do? - Drilled Piers

[Subject Prev][Subject Next][Thread Prev][Thread Next]
Rich,

I worked on a project similar to what you are describing.  We added 3
floors of residential on top of an existing concrete building that was
used for printing presses.  We had a geotechnical company do a couple of
non destructive tests to determine some information about the caissons
and also the allowable bearing pressure.  I forwarded you post on to a
gentleman from that firm, below is his response:

	We did essentially two things at 2001 S Calumet.  The first was
NDT 
	testing of the shafts to confirm the depth and whether there
were in 
	fact bells.  It does not look like that would be necessary on
the 
	referenced project.  The other work we did was pressuremeter
testing 
	(PMT), to confirm the available bearing for the shafts....  The
PMT 
	gives us stress strain data that can allow us to make much
better 
	analyses of settlements, therefore leading to generally higher 
	allowable bearing pressures as most bearing capacity
recommendations 
	are based upon settlement.  We can perform the PMT testing at an

	adjacent location, we don't have to drill right at the shaft
(but the 
	closer the better).  Also, the main concern is additional,
incremental 
	load increase and its associated settlement.

	He mentions expansive soils, I assume the project is not in IL?
We 
	have offices from PA to FL, GA to TX and of course here in IL.
I have 
	dealt with expansive soils in KS, and TX and know of them in
other 
	areas too.

	Let me know if we can help you or your colleague out.  We have
had 
	tremendous success in using PMT for projects just like this. 

	Please call me if you want to discuss this further.  I believe
we can 
	help make this project work. 

	Take care 

	Brett Gitskin, P.E. 
	Vice President 
	Engineering Consulting Services, Ltd. 
	Chicago Regional Office 
	1575 Barclay Blvd. 
	Buffalo Grove, IL 60089 


Hope this helps.

Brian M. Spencer
TGRWA, LLC
407 S. Dearborn, Suite 900
Chicago, IL 60605
p. 312.341.0055x20
f. 312.341.9966
bspencer(--nospam--at)tgrwa.com


-----Original Message-----
From: richard lewis [mailto:rlewistx(--nospam--at)juno.com] 
Sent: Monday, September 08, 2003 3:46 PM
To: seaint(--nospam--at)seaint.org
Subject: What would you do? - Drilled Piers

I am working on adding office space on the roof of an existing building.

I have some of the original design drawings from the 1965 construction. 
The steel columns have sufficient capacity fro the additional office
loading.  The foundation is a problem.  The general notes state that the
drilled piers were designed for a gross allowable soil bearing pressure
of 4,000 psf.  The ends are belled.  The soil is probably expansive
clay.
 No soil borings available and the original design engineer is gone. 

The existing drilled pier is 4 ft. dia.  For the added load I need 5 ft.
dia. for the soil bearing value.  If I use the 4 ft. dia. the soil
bearing pressure is about 6,000 psf.

What would you do?  I can't reasonably take borings because it is inside
a nursing home.  It sits up on the peak of a  hill so taking borings
outside probably wouldn't be difficult and is significantly away from
the
area of the proposed addition.

Appreciate any insight you might have.

Rich

________________________________________________________________
The best thing to hit the internet in years - Juno SpeedBand!
Surf the web up to FIVE TIMES FASTER!
Only $14.95/ month - visit www.juno.com to sign up today!

******* ****** ******* ******** ******* ******* ******* ***
*   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) or UnSubscribe, please go to:
*
*   http://www.seaint.org/sealist1.asp
*
*   Questions 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) or UnSubscribe, please go to:
*
*   http://www.seaint.org/sealist1.asp
*
*   Questions 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
******* ****** ****** ****** ******* ****** ****** ********