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

RE: Underground Structures

[Subject Prev][Subject Next][Thread Prev][Thread Next]
I don't know what the nature of your structure is, but if it is something
long like a utilidor you might want to look at a recent publication entitled
"Response of Buried Pipelines Subject to Earthquake Effects" published by
the Multidisciplinary Center for Earthquake Engineering Research in Buffalo,
NY. One of the authors is Dr. M.J. O'Rourke, who I heard among others at an
ASCE Lifeline Engineering conference in Seattle last year. I think O'Rourke
is at the State University of New York at Buffalo. MCEER has a website
mceer.buffalo.edu and a phone 716-645-3391. There is another Dr. Tom
O'Rourke, I believe from Cornell, who has also published extensively on this
subject. 

I listened to a number of presentations involving underground structure
design at the above conference, and was impressed by the complexity of the
subject. Some of the presenters ended up doing three-dimensional finite
element modeling of soil-structure interaction, and it's a long way from a
quick-and-dirty method we all wish was available. 

You probably want to make your structure as flexible as you can, since a lot
of the induced forces in the structure are due to the structure trying to
match the deformation of the surrounding soil as the waves pass through.
It's a different animal from an above grade problem, where amplification
effects are predominant. If your structure is pretty compact, the relative
distortions might not be too bad. But for something longer, you could have
parts of your structure going in completely opposite directions. For
example, say you had a wave propogation velocity of 600 fps and a wave
period of .2 sec, that translates to only 60 ft per half-cycle.

The Army has a technical manual for design of tunnels and liners that might
give you a little insight as well. Try the following link.
http://www.usace.army.mil/inet/usace-docs/eng-manuals/em1110-2-2901/toc.htm

These problems are real stinkers. Good luck.




-----Original Message-----
From: Vinod Sahni [mailto:SAHNIVK(--nospam--at)nv.doe.gov]
Sent: Wednesday, August 02, 2000 2:08 PM
To: seaint(--nospam--at)seaint.org
Subject: Underground Structures


I am working on the conceptual design of underground structures
(seismic zone 4 criteria).  The structures are buried some 150 feet below
ground.  Because of inexperience with underground structures and the
fact that it is conceptual in nature, I am analyzing for vertical loads only
at
this time.  I am wondering how I will tackle seismic design later.  I assume
a geotechnical firm would provide seismic accelerations at the depths
required.  Do I apply these accelerations like in a conventional 
aboveground structure ignoring passive resistance of the soil
(conservative). And,  I hope it is not some complex soil structure
interaction analysis involved here.  Are there some good practical
resources on the subject?  Any suggestions/recommendations would be
greatly appreciated.  Thanks.

******* ****** ******* ******** ******* ******* ******* *** 
*   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 
******* ****** ****** ****** ******* ****** ****** ********