Volex Labs / Calculations / CPT-based pile design (cone penetration test).

CPT-based pile design (cone penetration test).

Enter the CPT profile (cone resistance qc and sleeve friction fs), and Volex Anvil computes the pile capacity directly from the in-situ data: the average unit shaft friction, the shaft capacity Qs, the base resistance from qc, and the factored design capacity.

CPT-based methods (LCPC, Robertson) are among the most reliable for pile design; the unit values and totals follow Lunne, Robertson & Powell, 'Cone Penetration Testing in Geotechnical Practice'.

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What Volex Anvil checks

Validated against the published example

CPT pile capacity — unit shaft friction and shaft resistance Lunne, Robertson & Powell §5 — CPT pile design
QuantityPublishedVolex AnvilError
Average unit shaft friction qs78 kPa78 kPa0.00%
Shaft capacity Qs1225 kN1225 kN0.00%
This case is one of 359 published checks the platform passes — the full table, with every source and every error, is public at volexlabs.com/verification.

Frequently asked

Which CPT method?
Direct CPT methods (LCPC and Robertson) that scale shaft and base resistance from qc and fs, avoiding the intermediate soil-parameter step.
Does it classify the soil?
Yes — the CPT soil-behaviour-type index is reported, which drives the friction and base correlations.
Is it validated?
The unit friction and shaft capacity are checked against Lunne, Robertson & Powell — within 0.00%.
Free tier?
Yes — 10 calculations a month free; Pro (£29/month) adds unlimited runs and PDF calc sheets.

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