PileCalc
NAVFAC DM-7.02 · Vesić (1977) · Reese & O'Neill (1988) t-z

Axial capacity and settlement, with the whole curve visible.

NAVFAC DM-7.02 capacity — side friction, end bearing, limiting depth, downdrag, uplift — plus Vesić settlement and the full t-z / q-w load–settlement curve, in your browser.

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Capacity follows the NAVFAC DM-7.02 / AllPile procedure: adhesion (α-method) side resistance in clay, K·σ'v·tanδ in sand, bearing-factor end bearing with the 20-diameter limiting depth, zero and negative (downdrag) zones, battered piles, and separate factors of safety for side, tip and uplift.

Settlement is computed two ways: Vesić's (1977) three-component method and a t-z / q-w load-transfer solve using the Reese & O'Neill (1988) normalized curves — so you see the entire load–settlement response, not just one number at ultimate.

Capacity breakdown

Side and tip resistance reported separately, segment by segment down the pile, with the limiting-depth cap applied transparently.

Downdrag & uplift

Negative skin friction zones with a reduction factor, effective pile weight, and uplift capacity with its own factors of safety.

Load–settlement curve

The full t-z / q-w head curve, plus capacity at an allowable settlement if you set one.

Layered axial profiles

Multi-layer soil profiles, explicit groundwater, battered axial piles, and transparent per-layer resistance.

Validated against published benchmarks

Every figure below is produced by the engine on the cited published problem — closed-form solutions, design-manual tables, or independent codes — and reproduced by the test suite on every release.

NAVFAC DM-7 static method; NAVFAC Nq table; Skempton Nc

QuantityPileCalcReferenceAgreement
Bearing factor Nq, φ = 32° (displacement pile)NAVFAC DM-7.02 Table 8-129.1029.1exact
End bearing Qₚ = 9·cᵤ·Aₜᵢₚ (cᵤ 90 kPa, D 0.457 m)Das, Principles of Foundation Engineering 8e (2016), Ex. 9.7132.9 kN132.9 kNexact
Deep end-bearing factor Nc (z/B > 4)Skempton (1951) / Das — limiting Nc9.009.0exact
See the full per-tool validation report

The numbers, published

PileCalc's engine is checked term-by-term against the reference codes. A representative sample of the benchmarks — every intermediate value is visible in the app so you can reproduce them yourself.

Free-head pile (EI 1.43×10⁶, D 1 m, L 24.4 m)Liang et al. (2014) exact solution / RSPile
Max moment
792.2 kN·m
792.1 kN·m (exact)
within 0.1%
Fixed-head pile (EI 1.43×10⁶, D 1 m, L 24.4 m)Liang et al. (2014) exact solution / RSPile
Head moment
−581.1 kN·m
−581.0 kN·m (exact)
within 0.1%
Cantilever pile (EI 320, D 0.1 m, L 5.25 m)Liang et al. (2014) exact solution / RSPile
Head deflection
8.75 mm
8.750 mm (exact)
within 0.1%
Cantilever pile (EI 320, D 0.1 m, L 5.25 m)Liang et al. (2014) exact solution / RSPile
Max moment
2.335 kN·m
2.334 kN·m (exact)
within 0.1%
Circular pile, API sand (D 0.5 m, L 10 m, H 100 kN)RSPile verification manual
Deflection & moment profile
RSPile 2018 problems #1/#2/#8/#15
chart-reading tolerance
within 1–3%
Steel pile, multi-layer slope stabilization (17 m)RSPile / TZPile / LPile
Lateral resistance
607 kN
582 kN
within ~4%
Read how we validate — and why against two independent codes

Axial capacity & settlement: common questions

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