[TowerTalk] Base Anchor Bolts

[Bryan Swadener]

The anchors I ordered from UST for my TX472 were Type-F.
IIRC, they were 1-1/8" diameter x 27" L.  Yes, I could've
researched them and saved some money by buying them
from someone else.  However, the cost from UST didn't
break the bank, and they were a phone call away.
 
vy 73,
Bryan WA7PRC
________________________________
Date: Sun, 3 Nov 2013 01:13:53 -0500
From: Matt KM5VI
Subject: [TowerTalk] FW:  Base Anchor Bolts

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