Essential Terms in Helical Pile Design & Installation | Helical Glossary

  • Product Family IDEAL
  • Subcategory ELEMENT
  • TIP Category DESIGN
  • Tags HELICAL

TIP Description

Listed below is a glossary of terms related to helical design and helical installation.

Get Acquainted with Helical Product Terms

  1. 1. Anchor (Tie-back) – For resisting upward forces, lateral forces, and
    overturn movements. A helical unit in tension is an anchor or tie-back
    (A helical unit in compression is a pile or pier).
  2. 2.Axial Load – Load in line with axis of pile.
  3. 3.Batter Pile – Pile driven at an angle. Often to reduce lateral forces.
  4. 4.Bearing Stratum – Any soil layer which provides a significant portion of
    the axial load capacity by applying resistance to one or more of the
    helical plates.
  5. 5.Dead Load – The load of the structure with no outside forces acting on
  6. 6. Design Load – Dead Load plus Live Load. Also known as; Working
    Load, Allowable Load, and Service Load.
  7. 7.Effective Torsional Resistance – The average installation torque
    typically taken over a distance equal to the last three feet of
    installation or the last three diameters of penetration of the largest
    helix plate.
  8. 8. Fetch Up – Attaining specified torque with or without reaching glacial
  9. 9.Flight Pitch – Distance from the top of the top end of a helix to the top
    of the bottom end.
  10. 10. Helix (pl. Helices) – A spiral-shaped steel plate extending out from the
    shaft at a 90-degree angle at all points and traveling one
    circumference of the shaft. (Plural form said he/less/seas).
  11. 11. KIP – 1,000 lbs of force.
  12. 12. Live Load – The forces not calculated in a Dead Load. These forces
    could include people, furniture, animals, cars, weather, machinery, etc.
  13. 13. Load Overview – Dead Load + Live (Active) Load = Design (Working
    or Allowable or Service) Load X Safety Factor (Usually 2 but don’t
    assume) = Ultimate (Test) Load.
  14. 14. Mechanical Strength – The maximum load resisted by the structural
    elements of a helical pile without permanent deformation of the
  15. 15. Pier or Pile – To create a deep foundation where a shallow foundation
    is not adequate. For new or existing structures. A helical unit in
    compression is a pile or pier (A helical unit in tension is an anchor).
  16. 16. Post Grouted – Placing Grout inside and installed pile. Pile typically has
    a plugged leading end.
  17. 17. Post Tensioned to Load – Using force to load an anchor. Usually when
    there can be no movement under working conditions. Can be done on
    every anchor when no movement is critical.
  18. 18. Spin Out – Sitting on rock- end bearing- no real torque.
  19. 19. Static Load Test – Loading a pile under test conditions. Allowable
    movement is dictated by engineering or building department.
    Standard is ASTM D1143 for Compression. D3689 for Tension.
  20. 20. Torque Correlation – The relationship between the force required for
    installation and the Theoretical Ultimate capacity of the installed pile
  21. 21. Ultimate Load – Design (Working/Allowable/Service) Load multiplied
    by a safety factor which is often 2. This is the need-to-know number. –
    Sometimes called the Test Load or the Factored Load but be careful to
    get clarification of the phrase “Factored”. “Factored” load may refer to
    LRFD design philosophy which is not used for Helicals.
  22. 22. Value Engineering (VE) – Designing in a cost-effective manner. Often
    referring to a re-design with a more cost-effective solution.

Tim Comb


Tim is the President of Intech Anchoring and has 25 years of experience in the Civil Engineering and Geostructural Industry. Tim has developed extensive industry knowledge by working to support the needs of specialty contractors at each and every business level. Tim’s diverse industry background has given him exposure to a wide variety civil construction projects, ranging from the simplest residential applications to the most complex commercial and industrial projects. Coupled with a highly skilled and educated team, Tim focuses on providing the highest quality products and solutions to Intech Anchoring’s customers in order to consistently exceed expectations.