This calculator evaluates the selected empirical correlation Q = KtT and converts units. It does not establish a design capacity. ICC-ES AC358 requires Kt to be verified by full-scale field installation and load tests for the pile system, and actual design remains site- and product-specific.
Selected Helical-Anchor Torque Correlation
Evaluate a selected helical-anchor torque-correlation product and ideal pitch per revolution.
Equation Used
- T is a selected final installation torque value.
- Kt is a selected empirical factor already established for the applicable evaluated pile system and test basis.
- Pitch is shown as ideal geometric advance per revolution only.
- Soil profile, load testing, structural limit states, code checks and professional design are excluded.
Do not use this calculator to design, select, install or approve a helical anchor or pile.
Connected installation reference
The animation shows a shaft and attached helix rotating together while advancing one selected pitch per revolution. Torque and conditional uplift arrows respond to the selected values.
The soil layers are schematic. No soil failure surface, bearing zone, embedment, shaft resistance or frost behavior is calculated.
What the calculator determines
Select final installation torque T, a capacity-to-torque factor Kt, and helix pitch p. Outputs are the conditional product KtT in pounds-force and kilonewtons, torque converted to kN·m, and selected pitch per revolution.
Do not use these outputs to select, install or approve an anchor. A registered design professional must apply the applicable evaluation report, site investigation, field torque procedure, structural limits and load verification.
Selected empirical correlation
Qcorr = KtT, QkN = 0.004448221615Qlb, TkN·m = 0.001355817948Tft·lb, and ideal advance per revolution = p.
ICC-ES AC358 states that Kt is a capacity-to-torque ratio for a given pile type, must be verified by full-scale field installation and load tests, and is subject to the criteria's shaft-size scope.
Arithmetic example, not a design value
For selected T = 1,000 ft·lb and Kt = 10 ft⁻¹, the conditional product is 10,000 lb (about 44.5 kN). A selected pitch of 76 mm/rev is reported as 76 mm per ideal revolution.
Safety and scope boundary
Torque correlation is empirical. Kt depends on the qualified shaft and helix system and its test basis; capacity is also limited by soil, helix, shaft, couplings, brackets and other applicable limit states. The former page's generic soil-specific Kt advice, installation prescriptions and claims that the equation removes the need for site investigation are removed.
No allowable load, factor of safety, code compliance, lateral capacity, compression capacity, installation depth or structural resistance is produced here.
Questions
Is Qcorr an allowable load?
No. It is only the selected correlation product.
Can I choose Kt from a generic soil description?
Not with this calculator. Use the applicable evaluated system data and site-specific professional design.
Does pitch determine actual advance in soil?
The visual shows ideal geometric advance; real installation can disturb soil, slip or refuse.
Can this approve an installation?
No.
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