Evaluation Report CCMC 13268-R
Géopieux / Geopile

"Géopieux / Geopile" is an earth anchor constructed of a single helical-shaped circular steel blade welded to a steel shaft.

The blades are available in diameters of 254 mm and 305 mm with a thickness of 9.5 mm and in diameters of 356 mm, 380 mm and 407 mm with a thickness of 12.5 mm. They are constructed as a helix with a carefully controlled pitch. The diameter of the blade is chosen based on the bearing capacity of the soil and the load that the auger-installed steel pile is designed to support.

The steel shaft is available in a diameter of 60.3 mm with a wall thickness of 4.7 mm or a diameter of 89 mm with a wall thickness of 3.18 mm. The central shaft is used to transmit torque during installation and to transfer axial loads to the helical blades; it also provides most of the resistance to lateral loading.

The foundation system comes with other accessories, such as support plates to adapt it to the building structure, extension shafts and connectors.

The steel shaft, blades and accessories conform to CAN/CSA-G40.21-04, "Structural Quality Steels," and have a galvanic coating of 610 g/m³ that meets the requirements of CAN/CSA-G164-M92, "Hot Dip Galvanizing of Irregularly Shaped Articles."

The piles are screwed into the ground using mechanized equipment. Sufficient downward pressure (crowd) is applied to advance the anchor one pitch distance per revolution until the applied torque attains a specified value. Extensions are added to the central shaft as needed. The applied loads may be tensile (uplift), compressive (bearing), shear (lateral), or a combination thereof. The piles are rapidly installed in a variety of soil formations and are immediately ready for loading after installation.

Figure 1 shows a typical steel pile with a single helix.

• The product may be used as a foundation system to support various constructions, provided that it is installed according to the manufacturer's current instructions and within the scope of this Evaluation Report.
• Where the product is installed in granular soil or silt, there is a direct relationship between the applied torque and the allowable compressive loads, which are indicated in Table 1.
• Where the product is installed in a cohesive soil such as clay, the relationship between the applied torque and the allowable compressive load is not predictable; as such, the allowable compressive loads must be confirmed by on-site load tests. These load tests are also required if the allowable loads exceed those stated in Table 1. The tests must be conducted under the direct supervision of a professional geotechnical engineer skilled in such design and licensed to practice under the appropriate provincial or territorial legislation.
• In all cases, a registered professional engineer skilled in such design and licensed to practice under the appropriate provincial or territorial legislation must determine the number and spacing of the auger-installed steel piles required to carry the load. A certificate attesting to the conformity of the installation and the allowable loads for the piles must be provided.

  Table 1. Allowable Compressive Loads for the "Géopieux / Geopile" Auger-Installed Pile in Granular Soil or Silt^{Table 1 footnote 1}

  Applied Torque		Allowable Compressive Loads
  Nm	lbf	kN	lb
  1 356	1 000	20	4 500
  1 695	1 250	25	5 625
  2 034	1 500	30	6 750
  2 373	1 750	35	7 875
  2 712	2 000	40	9 000
  3 051	2 250	45	10 125
  3 390	2 500	50	11 250
  3 728	2 750	55	12 375
  4 067	3 000	60	13 500
  4 406	3 250	65	14 625
  4 745	3 500	70	15 750

  Notes to Table 1:

  Footnote 1

  The allowable loads identified in this Table are only valid when the product is installed in granular soil or silt. Special attention is required when the auger-installed steel piles are installed in recently backfilled sites or in cohesive soils. In these cases, Table 1 does not apply and the allowable loads must be determined by on-site confirmatory testing.

  Return to table 1 footnote 1 referrer

• Where the product is installed in soil conditions that are corrosive to steel, adequate protection of the exposed steel must be provided.
• To be permitted to install "Géopieux / Geopile" auger-installed steel piles, the installer must be certified by Géopieux (90906173 Québec Inc.). Using approved equipment, the installer must follow the manufacturer's installation instructions and heed the uses and limitations specified in this Report. Each installer must carry a certification card with their signature and photograph.
• Each "Géopieux / Geopile" auger-installed steel pile must be identified with a label containing the following information: manufacturer's identification; and the phrase "CCMC 13268-R."

“Géopieux / Geopile” auger-installed steel piles were tested to ASTM D 1143-07e1, “Deep Foundations Under Static Axial Compressive Load.”  A series of 6 tests were conducted on three different sites with granular soil to determine if there is a correlation between the torque applied during installation and the allowable compressive load: the results confirmed that there is a correlation.  For the compressive loads noted in Table 1, the factor of safety is 2.