Selection Table

Selection Table – English USA (.Pdf)

Model Project Type Maximum Allowable Bearing Capacity1234 Allowable Lateral Capacity5 Maximum Installation Torque Allowable Bending Resistance7
Compression (lb) Tension (lb) lb ft-lb ft-lb
P1
Ø 1.9 in
Light Residential
(deck without roof, stairs, etc.)
6,700 3,350
to 4,450
250 1,3368 785
P2
Ø 2.4 in
Medium Residential and Light Commercial
(deck, carport, sunroom, single-story residential addition, etc.)
11,200 5,600
to 7,450
550 2,2428 1,360
P3
Ø 3.5 in
Heavy Residential, Light to Medium Commercial and Industrial
(two-story residential addition, cottage, sign, carport, solar panel, new construction, underpinning, boardwalk, tie-back, etc.)
29,800
to 33,000
15,000
to 19,850
1,200 8,5098 4,571
P46
Ø 4 in
Heavy Residential, Light to Medium Commercial and Industrial
(cottage, sign, light post, solar panel, new construction, boardwalk, tie-back, bollard, etc.)
36,000
to 45,000
18,000
to 30,000
1,500 11,000 6,371
P3-HD6
Ø 3.5 in
Heavy Residential, Light to Heavy Commercial and Industrial
(new construction, underpinning, tie-back, etc.)
38,000
to 45,000
19,000
to 30,000
1,400 11,000 6,428
P4-HD6
Ø 4 in
Heavy Residential, Light to Heavy Commercial and Industrial
(new construction, retaining wall, tie-back, etc.)
44,000
to 50,000
22,000
to 33,000
1,500 14,500 8,944
P56
Ø 5.6 in
Heavy Residential, Light to Heavy Commercial and Industrial
(cottage, sign, light post, new construction, boardwalk, solar panel, bollard, retaining wall, etc.)
30,000
to 50,000
15,000
to 33,000
2,750 14,5009 14,713
P66
Ø 6.6 in
Heavy Residential, Light to Heavy Commercial and Industrial
(sign, light post, new construction, solar panel, bollard, retaining wall, etc.)
30,000
to 50,000
15,000
to 33,000
3,700 14,5009 23,142

 

Notes

  1. The maximum compressive bearing capacity (allowable load) includes a safety factor of 2.
  2. The maximum bearing capacity (allowable load) is determined by the maximum torque applied by the installation equipment.
  3. When the helical foundation is laterally unsupported (soil very loose / soft, liquefiable soils, water current and wind), the structural strength of the helical foundation must be approved by TMP Engineering Department.
  4. For tension applications, the helical foundation must be installed such that the minimum depth from the ground surface to the helix is 12D, where D is the diameter of the helix. Contact TMP Engineering Department for tension applications when 12D cannot be maintained.
  5. Lateral capacity is based on medium dense soils with free head condition with a maximum distance in air or fluid soils of 6’’ and embedment of 7 feet. Contact TMP Engineering Department for other conditions.
  6. TMP Model P4, P3-HD, P4-HD, P5, and P6 are subject to site specific engineering. TMP Engineering Department approval is required to use the upper capacity values shown in table.
  7. Allowable bending resistance is based on calculations assuming bare steel, 50 years corrosion per AC358 and 1.67 safety factor.
  8. Maximum installation torque for P1, P2, and P3 are based on IAPMO-UES Evaluation report no. 481.
  9. Maximum installation torque for P5 and P6 are limited to the maximum torque of the ET1 installation equipment.

Comments

  • For any technical questions, please contact the TMP Engineering Department.
  • Larger Techno Metal Posts can be used for applications requiring a lateral or bending resistance higher than shown in the selection table.