Helical Pile or Ground Screw

Helical Pile or Ground Screw:

Helical piles are a form of prefabricated deep foundation. As hinted in its name, helical piles differ from other deep foundations and are most notable for having spiraling blades along their shafts, as opposed to having a relatively uniform shape like driven piles and micropiles.

Some other names for helical piles include helical piers, helical anchors, screw piles, and screw foundations. While there may be some minor differences in particular naming conventions, these names are often used interchangeably. At the very least, the principle between all of these remain the same. 

Drilled Cast-in-Place Concrete Piers:

• 12” diameter piers
• 6’-0” deep piers for the (2) Back Legs; 5’-0” deep piers for the (2) Front Legs
• Rebar cages required (amount dependent on seismic design category of site)

Driven Steel Piles:

• W6x7 pile assumed (4” wide by 6” deep with a steel weight of 7 lbs. per foot)
• 7’-3” deep piles for the (2) Back Legs; 6’-0” deep piles for the (2) Front Legs

• Each helical pile or grounds screw is installed in the range of 5 to 6 ft. (typical).
• Load tests required using a minimum factor of safety of 1.5 and typically higher when only a select number of anchors are tested (per anchor manufacturer).
• Provide a summary of the tested loads to the Engineer of Record for review, approval, and submittal to the governing jurisdiction.

Earth Anchor:

• Each anchordrivento around 2 ft. deep (average for most Osprey installations)
• Load test Back Leg anchors to 1400 lbs. and Front Leg anchors to 500 lbs. (factor of safety of 1.5).
• Provide a summary of the tested loads to the Engineer of Record for review, approval, and submittal to the governing jurisdiction.