[TowerTalk] ROHN tower anchor question

[Mark]

ROHN drawing C620643 titled "Standard Concrete Anchors" shows uplift and
lateral capacity in lbs for each of the anchors. How does ROHN derived at
these numbers?

For exampe a 3 foot by 3 foot by 1.5 foot of concrete that is buried 4 foot
down into the ground has a up lift capacity of 3,490 lbs. and a lateral
capacity of 5,850 lbs.  The concrete weighs 1,890 lbs.  NOTE is provided by
ROHN that states "The soil is cohesive with an allowable net vertical
bearing capacity of 4000 pounds per sq. ft.(psf) and allowable net
horizontal pressure of 400 psf per lineal foot of depth to a maximum of 4000
psf."

How do they crunch the numbers to determine the the uplift and lateral
capacity of the anchor?


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