Yep, because closely spaced bolts can more easily pull out a *chunk* of
concrete containing all the bolts than widely spaced ones. I was
thinking of bolts *slipping* out of the concrete.
-Steve K8LX
On 03/24/18 19:11 PM, Mike Fahmie via TowerTalk wrote:
No, the pull out strength will depend on how far apart the anchors
are. Closely spaced anchors will compromise pull out strength.
Optimum spacing will depend on anchor depth.-Mike WA6ZTY
From: Steve Maki <lists@oakcom.org> To: towertalk
<towertalk@contesting.com> Sent: Saturday, March 24, 2018 4:07 PM
Subject: Re: [TowerTalk] Achor bolts?
How many bolts? Obviously 10 bolts will have 10x the strength of
one, including pull out strength.
Most SS towers are designed for fewer large bolts rather than many
small bolts. Part of the reason for that is corrosion concern.
Let the flange hole size be your guide! Of course, take a quick
glance at the manufacturer's foundation plans...
-Steve K8LX
On 03/24/18 9:34 AM, Hans Hammarquist via TowerTalk wrote:
Dear towertalkers,
The are claims in a discussion on Face Book that an anchor bolt,
"5/8 in. x 12 in. Hot-Galvanized", is suitable for a free standing
tower. Someone even claims it is used for a 400' freestanding
tower. It doesn't make sense to me but I might be overly
pessimistic.
I hate to start lengthy discussions and this might be one of them
so, please, comment only if you have a well grounded answer. I'm
sure there are plenty of opinions about it like my own, but I would
like to know if my guts feeling is right or wrong. What I am afraid
of is that you can pull out an anchor bolt like that right out of
curred concrete.
73 de,
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