Endformed Helical Pile Extensions

The next generation of helical piling connection solutions

Endformed Connection System John Lawrie Tubulars
  • Endformed Helical Pile
  • Endformed Helical Pile

Extending helical piles for deep foundations

John Lawrie Tubulars (JLT) introduces the next generation of connection solution for extending helical piles for deep foundations. The new Endformed Helical Pile Extension has been developed through a rigorous Four-step design and testing approach using laboratory testing, structural engineering analysis, field testing, and proprietary manufacturing processes. The EndFormed Extension is a more cost-effective connection technology compared to currently available systems. The extension and coupler are endformed using a single piece of pipe.

At a glance

  • Lower cost coupler – no welding required
  • Can endform any wall thickness available per pipe size up to 0.500” wall thickness.
  • Can endform all yield strengths readily available on the market such as API (J55, L80 and P110), ASTM A252, ASTM A500, and CSA G40.21.
  • In torsion, the EndFormed connection performs within industry standards (ICC-ES AC358) when compared to welded couplers.

Benefits of the Endformed Connection System (for driven and helical products)

  • Efficiency in the field – self-aligning connection
  • Lower cost – the EndFormed connection is the cost of 8” of the original pipe diameter compared to the cost of a larger diameter splice coupler or field weld
  • Excellent lateral and moment rigidity
  • No field beveling and welding time or cost compared to other splicing couplers
  • Multiple wall thicknesses (up to 0.500”) can be endformed to offer design flexibility
  • Endformed products available in various yield strengths such as API (J55, L80 and P110), ASTM A252, and ASTM A500
  • Endformed extensions can be fabricated to client provided designs

Endformed Helical Pile Extension Sizes

Pipe Grades
API ASTM
Pipe Diameter (inches) Wall Thickness (inches) J55 L80 P110 A252/A500
2.875 0.217 – 0.308 Y Y Y Y
3.500 0.250 – 0.500 Y Y Y Y
4.500 0.205 – 0.430 Y Y Y Y
5.500 0.244 – 0.500 Y Y Y Y
7.000 0.231 – 0.498 Y Y Y Y
7.625 0.300 – 0.500 Y Y Y Y
8.625 0.264 – 0.500 Y Y Y Y
9.625 0.312 – 0.500 Y Y Y Y
Endformed Helical Pile Extensions

Structural Engineering Analysis (ICC-ES AC358 – Acceptance Criteria for Helical Pile Systems and Devices)

Using 5.5” x 0.361” pipe and coupler samples in three steel grades, JLT performed tests on EndFormed and Welded Coupler samples to compare performance. Using an AC358 accredited laboratory, JLT conducted a full set laboratory tests to determine structural performance of the EndFormed coupler in torsion, compression, bending and lateral loading. The empirical test results were used to validate the structural engineering analyses. All other available sizes had structural analyses completed with full engineering technical packages available for four grade specifications (ASTM & API)

Design References
AISC 15th Edition, AISC 360-16, 2020 AC358, ASCE 20

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