The link below shows some diagrams of different anchor bolt types. Which
ones do you have? The last HDX572 design calculations I have from UST
specify (6) 1" by 27" ASTM F1554, grade 55 (55,000 psi yield), with type E
block arrangement using a 2" square x 5/8" thick A-36 (36,000 psi yield)
steel block welded to the top die of the nut. Min embedment was 21". This
arrangement with a 5.5' x 5.5' x 7.5' footing was rated at 55,000 ft lbs
overturning moment in 100 psf soil.
http://stanley-sales.com/media/e5b0d8a7677e8f11ffff89b7ffffe904.jpg
I know that the ASCE revised the their standards a few years back resulting
in more conservative designs for anchor bolt pull-out strength. We
routinely run computer analysis for anchor pull-out these days considering
not only the embedment but also the overall geometry of the footing, The
last two shipments of grade 55 anchor bolts I purchased from my anchor
supplier were fabricated to the new ASTM F1554 standard and were Type F
with the heavy square block sandwiched between two welded nuts. FYI -
bolts I received from UST under the old design standards were ASTM A36
(36,000 psi) with Type D washer & nut welded to the base.
I have never heard of an anchor bolt pull-put failure on a UST. I would be
curious if anyone on the reflector has?
Hope this helps,
Matt
KM5VI
-----Original Message-----
From: TowerTalk [mailto:towertalk-bounces@contesting.com] On Behalf Of Mike
Fahmie
Sent: Saturday, November 02, 2013 8:49 AM
To: towertalk@contesting.com
Subject: [TowerTalk] Base Anchor Bolts
My HDX-572MDPL came with 1" anchor bolts with a welded nut at the bottom.
The nut diameter is only slightly larger than the shaft so I am considering
the addition of a heavy washer wired against the nut to increase the
'grab'. Is this a good idea?
How does the welded nut approach compare with 'L' shaped anchor rods?
-Mike-
WA6ZTY
_______________________________________________
_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk
-----
No virus found in this message.
Checked by AVG - www.avg.com
Version: 2013.0.3426 / Virus Database: 3222/6803 - Release Date: 11/02/13
_______________________________________________
_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk
|
