Helical Anchors

Helical screw-in anchors are a quick, simple and reliable means of creating secure fixing points in the ground. Manufactured from galvanised steel, they consist of an anchor shaft with an angled disk at the lower end. The upper end of the shaft, depending on usage, has either a closed eye for cable or chain connections or is threaded for securing plates and nuts.


Installation

Installation is either by hand or by powered augering but requires no large or expensive equipment. The achievable holding capacity is dependent upon the ground conditions but with the correct anchor in the right conditions holding capacities of up to 50kNs are attainable.

As the anchors are screwed in they can, when not in use, be unscrewed for re-use at other locations.

With their ease of operation, helical anchors are ideal for confined spaces and avoid damage both to the soil structure or crops and to nearby structures and can be loaded to their full capacity immediately after installation.


Anchor Selection

The length and diameter of the shaft and the diameter and thickness of the anchor disk are dependent upon the anchor's purpose, the screw-in depth and the required holding capacity. Anchor Systems can advise on the most suitable type and size of anchor but will require information on its intended use, loading capacity and the ground conditions present.

Anchor holding capacity (pull out strength) in kN, depending on nature of soil, diameter of anchor disk and installation depth.

Determination of Soil Types
Type A
Heavy soil, dense, fat clay, very dried-out, mixed with pebbles, detritic matter or gravel
Type B
Gravel mixed with sand, medium grained gravel (semi heavy soil)
Type C
Coarse grained, well settled gravelly soil
Type D
Agglomerate soils, of medium consistence soft clay, marl argillaceous loess
Type E
Primary backfill, low consistency ground, fine grained
Diameter of anchor disk in mm Installation depth in meter Types of soil / Pull out strength in kN
A B C D E
80 400 6.0 5.0 4.0 3.0 2.0
110 600 9.0 8.0 6.0 5.0 4.0
150 1200 17.0 14.0 11.0 9.0 7.0
200 1500 44.0 39.0 35.0 26.0 17.0

Contact us for more details.