Four engineering-grade foundation calculators — API RP 2A axial pile plus shallow Terzaghi, Meyerhof, and Brinch Hansen — with step-by-step working, automatic factor lookup, factor-of-safety check, and exportable report. Assumed values are marked with a red border and remain editable.
Driven / bored axial pile — API RP 2A.
Stack the borehole log top→down. Each layer: sand or clay, with its own — red-bordered, editable — API design parameters.
Red border = assumed / auto-suggested — verify against the soil report
Core inputs shared by the three shallow methods.
Red border = assumed / auto-filled — verify or override before use
Factors auto-recompute whenever φ or method changes. Edit a field to override; it stays overridden until you change φ/method again.
Important in Jeddah and the wider Saudi region.
Vertical load checks capacity. Horizontal load & moments unlock for Meyerhof / Hansen.
Recalculates as you type.
Active row matches your φ; in-between values are interpolated.
| φ (°) | Nₐ | Nₘ | Nγ |
|---|
Factor values vary slightly between references/codes. Override in the Assumed-values card if a local table is required.
Shaft resistance Qₛ built up layer-by-layer down the pile.
| Layer | Type | z (m) | f (kPa) | Qₛᵢ (kN) |
|---|
f = unit skin friction · Qₛᵢ = f × perimeter × layer thickness within the pile. Capped per API limiting values.
Shown for reference so the correct method can be identified. Name and governing equation only — no calculator. (API RP 2A is now a full calculator above.)
Scope & limits. API RP 2A axial pile capacity = skin friction (α·sᵤ in clay; β=K·tanδ × σ′ᵥ in sand, with limiting f) + end bearing (9·sᵤ in clay; σ′ᵥ·Nq capped in sand), per API RP 2A / RP 2GEO. Shallow methods below apply to spread footings (D₣/B ≤ 1), general shear failure. Terzaghi (1943) uses shape factors only. Meyerhof and Hansen add shape, depth, and inclination factors; Hansen adds ground-slope and base-tilt factors. Local-shear option applies c*=⅔c, tanφ*=⅔tanφ. Water-table correction uses the standard three-case γ′ method. Assumed values (red border) must be verified against the project soil report and the governing local code. For sabkha, collapsible, or otherwise problematic regional soils, classical values are indicative only — verify with CPT or plate-load testing. Bearing-capacity and correction-factor formulas follow standard references (Das, Bowles).