] [Thread] [Date] [Author]

[Chris Roper <croper(--nospam--at)bjginc.com>]

For what it's worth, I would say you do not have to consider this a
cantilevered column system.  The lateral force resisting system you're
concerned with is the building above grade.  The mat and piles are the
foundation at and below grade.  The structure above grade generates seismic
load and transfers it to the foundation.  If it's a metal building, wind
probably controls anyway.  Perhaps someone else will chime in and give us
some other schooling.

-----Original Message-----
From: Kevin Harris [mailto:Kevinh(--nospam--at)jhiengineering.com]
Sent: Thursday, July 19, 2001 1:24 PM
To: Seaint(--nospam--at)seaint.org
Subject: "Cantilevered Column" Structures


Greetings

I have a question that has been bugging me for awhile that I hope someone
can give me some guidance on.

Here are the facts:

1) A lightweight pre-engineered building (say 20 psf) bearing on a pile
supported mat that supports tanks and equipment (say 500 psf+).

2) UBC seismic zone 3.

3) Point of fixity of piles is 20 ft below grade, per geotech.

Would this structure have to be considered a "cantilevered column building
system" (R=2.2)?  I was wondering if I would be released from this low R
value because the structure is essentially just an equipment foundation.

Also, if I have to use R=2.2 for the foundation, would the light metal
building shell have to be designed with R=2.2 as well (unless it can be
shown to have 10 times the metal building stiffness)?

Thank you for your thoughts.

Kevin Harris, P.E.


* 
*   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 

* 
*   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