HomeMy WebLinkAboutPermit Correspondence 1995-2-1
I J
~
.
\; .
~
FROM: BU-I LE~ HA~DWALL GROUP
503 687 9451
TO:
FEE 1, 1995
4:21PM P.01
. "., ,
~(.tJ"/'/,
~
2J~o ~~tc..J
ardwaJ/
esign
ystems
Hardwall Design Systems
Post Office Box 419917
KanS4..~ City, MO 6414HJ917
Phone: (816) 968-4670
Fax. (816) 9684650
~/.~~ ;:;1j:,~ ;:i?f:(:" 1
- _...::... ...... .;.I.~~\"",.
February 1, 1995
"....
Pat Duerr
Chambers Consrruction Co.
2295 Coburg Road, Suite 100
Eugene, OR 97401
Re: Coast to Coast
Rebar ~pacing on Panels - PS, P7, & PI3
Dear Pat,
According to your memo, the vertical rebar spacing was placed at approximately 11-114" in full width of
each panel inStead of the required 8" spacing within an 8 ft. strip width under the beam supports on panel
PS, P7, and P13.
After reviewing this condition utilizing the same design process, these panels were 6% overstressed. But
since the effective 5trip width under a concenrratcd load varies from 4t to 24t (t = thickness of panel in
inches) ck.p.....ding on which design guidelines arc used. These panels are OK and well within a good
safety margin.
In our design J-'.~ures, we use an effective width of 12t. We feel that this is a good design approach
and has been used by many firms over the past 20 years. The ACI 551 committee on tilt-up construction
believes that the effective width to resist the concentrated load in tilt-up panels should be the width of
tearing plus a width described by sloping lines one horizontal to tWo vertical on each side of the bearing
to the critical design section. This would come out to about 24t if we used this criteria for Coast to
Coast The current rebar spacing on PS, P'7, and P13 creates an effective width of about 15t to our 12L
I hope I didn't get too wordy. I just wanted to give s........;, explanation as to why the above mentioned
situation is OK yet is oven;rressed using our current design procedures.
Any questions please give me a call.
JEecd
02101/95 WED 14.21 [TX/RX NO 5724]