Re: PEMB Foundation Uplift

Jeff:

 

If you have footings and slab that are connected to the pad, you could include some of those in the dead load as well.

Farzin S. Rahbar, SE

Vice President
David C. Weiss Structural Engineer & Associates, Inc.
(818) 227-8040 Ex. 13 Fax: (818) 227-8041

-----Original Message-----
From: Jeff Hedman <jeff_h@lrpope.com>
To: seaint@seaint.org
Sent: Fri, Dec 3, 2010 8:42 am
Subject: RE: PEMB Foundation Uplift

Long,

I agree with you.  I was thinking about the same thing last night.  If I have 12300 lbs of uplift and 2700 lbs of structure weight, 0.6D+W = 0.6*2700 – 12300 = 10680 lbs of uplift.  I would then design the anchor bolts for this  force.  If I designed the footing to weigh 10680 lbs, my actual factor of safety would be (10680+2700)/12300 = 1.09, probably not necessarily the best idea.  So I have decided I will just multiply the footing weight by 0.6 and have even larger footings.  Although I am pretty sure I wont see the building rolling down the street in the next wind storm.

 

Jeff