Earth anchor

Single helix earth anchors
Guyed mast anchor

An earth anchor is a device designed to support structures, most commonly used in geotechnical and construction applications. Also known as a ground anchor, percussion driven earth anchor or mechanical anchor, it may be impact driven into the ground or run in spirally, depending on its design and intended force-resistance characteristics.

Earth anchors are used in both temporary or permanent applications, including supporting retaining walls, guyed masts, and circus tents.

Typical applications

Earth anchors are typically used in civil engineering and construction projects, and have a variety of applications, including:

How they work

Once installed and load-locked, an earth anchor exerts effort to the soil above it, with the soil in turn providing resistance.[5] Upward soil compression created by the anchor is typically exerted in a frustum shaped cone,[6] reflecting:

When angled these lateral surfaces generate greater cone-shaped soil resistance than a simple cylinder created by purely perpendicular design.[7]


Site analysis determining soil load resistance is often required before earth anchor installation.[8] Included are depth that the anchor is to be driven, and soil strength, moisture content, and corrosivity.[9] When appropriate, test installations are done to determine optimal anchor design or conformance with project specifications.

Installation methods differ depending on soil composition and moisture.[8] Earth anchors are commonly driven into the ground using a drive rod and impact hammer. Pilot holes are required denser soils. After an impact driven anchor has been installed, the drive rod is removed and the anchor load-locked, typically by rotating it ninety degrees. For lighter anchors a hand tool is often sufficient.


  1. Platipus Anchors, retrieved 2012-07-09
  2. Geotechnical Engineering Circular No. retrieved 2012-07-09
  3. Platipis Anchors, retrieved 2012-07-09
  4. 1 2
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