A.B. Chance Earth Anchor Performace Compared to a
In a series of tests recently conducted by the A.B. Chance
Company, Centralia, Missouri, the holding power of a Chance
30" long earth anchor conclusively showed the anchor
dramatically outperformed a wood stake in guying applications.
Pull force applied with a Chance chain hoist and the force
measured with a dynamometer.
A Chance 30" by 11/18" earth with a 4" helical
plate anchor was installed by hand by screwing it into the
ground. The anchor rod was inclined 50 degrees to the horizontal
and screwed down until the eye was touching the ground. The
wood stake was made from dried oak. Nominal dimensions of
the wood stake were 1 3/4" x 2" x 42" long.
The stake was driven into the ground at an angle of 55 degrees
from the horizontal with a steel sledge hammer. The stake
was positioned so it was against the ground resisting the
force. The line of pulling force was 30 degrees from the horizontal.
When a force of 1,875 pounds pull was exerted on the anchor,
it showed its first sign of movement. After movement started,
the maximum holding load was 1,500 pounds. The maximum continous
creep load was 1,750 pounds.
Whena force of 1,000 pounds was pplied to the wood stake,
the stake moved through the ground four inches. At 1,150 pounds
force, the stake split. The stake continued to pull through
the ground at a maximum of 1,250 pounds.
For More Information:
Anchors (PDF 2MB)