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RE: Steel Conn in 1926 Bldg

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John:

Don't know if this will help, but it appears to be close.  I have a
Carnegie Steel "Pocket Companion" from 1923 and a 1921 book by Milo
Ketchum entitled "Steel Mill Buildings".  Both have a table of beam
connections with identical information.  The latter book's table is from
American Bridge.  Neither shows a 20"I 62, but both have a 20" I 65.4.
The shear connection is a double angle 4" x 4" x 7/16" x 0'-11 1/2" with
a single line of 4 rivets or bolts spaced at 3" in each leg.  The
allowable unit stresses for 3/4" rivets are 12000 psi and 24,000 psi for
shop rivets in single shear and bearing, respectively and 10,000 and
20,000 psi for field rivets.  They also give a bearing value of 30,000
psi for shop rivets where the web is enclosed between two angles.
According to the tables, the strength of the connection seems to be
35,300 lbs controlled by single shear (at 10,000 psi) on the 8
field-installed rivets connecting the outstanding legs of the angles to
the other beam web which has a minimum thickness of 5/8".  The capacity
of the 4 shop-installed rivets (which act in double shear) connecting
the two angles to your 20" beam web is 45,000 lbs controlled by bearing
(at 30,000 psi) on the 1/2" web of the beam.  Incidentally, the
properties of the 20" I 65.4 are as follows:
A = 19.08 in2
d= 20"
bf = 6.25"
tf = 1.029" to 0.550"
tw = 0.500"
I = 1169.5
S = 116.9
r = 7.83

Finally, if you would like to see the table (and a picture of this
connection) it's in a Word document on our ftp site at
ftp.hdrinc.com/4PJT/carnegie.doc

Hope this helps.

Tony Powers
HDR Engineering, Inc.

> ----------
> From: 	CPCeng(--nospam--at)aol.com
> Sent: 	Monday, August 25, 1997 3:13 PM
> To: 	seaoc(--nospam--at)seaoc.org
> Subject: 	Steel Conn in 1926 Bldg
> 
> I am working on a building designed in 1926.  I need to check the
> capacity of
> some beams at the mezzanine level, but there are no shear connection
> details
> in the plans, only a line in the structural steel section of the
> general
> notes that reads: "All steel connections to be Bethlehem standards or
> equivalent."  Rivets are shown as being good for 13000# in shear and
> 26000#
> in bearing when done in the shop, and 12000# in shear and 24000# in
> bearing
> when done in the field.  The particular beam I am looking at is noted
> as a
> 20" I 62.  Any information any of you might have on the way shear
> connections
> were typically done at that time would be appreciated.
> 
> Thanks,
> John Sullivan
> 
>