Validated against LPILE & RSPile

Deep-foundation analysis,
in your browser.

Laterally loaded piles, axial capacity & settlement, groups, drilled shafts and footings — the complete deep-foundation toolbox, with a genuinely modern UI and an explanation behind every single input. No Windows. No dongles.

Free to try — runs on any Mac, Windows, Linux or Chromebook.

Lateral · p-y
converged
SOFT CLAYDENSE SANDWEAK ROCKPy₀
16.1 mm
Head defl.
542 kN·m
Max moment
2.3 m
@ depth

Built on the methods the profession already trusts

FHWA COM624PReese p-yNAVFAC DM-7.02FHWA-IF-99-025API RP-2AVesić (1977)
One tool, full breadth

The whole deep-foundation toolbox

The desktop incumbents split this across four separate programs. PileCalc puts it in one place — every method documented, every assumption visible.

Laterally loaded piles

Deflection, slope, moment, shear and soil reaction by the p-y finite-difference method. Five head conditions, static or cyclic, layered soil, pushover load sweeps, cracked-section nonlinear EI.

FHWA COM624P / Reese p-y

Axial capacity & settlement

Downward and uplift capacity, limiting depth, Vesić settlement, and the full t-z / q-w load–settlement curve — with a dedicated neutral-plane downdrag tool alongside.

NAVFAC DM-7.02 · Vesić

Pile groups

Vertical ultimate/block resistance with explicit ASD, LRFD and sand-group service settlement; FHWA GEC 9 row p-multipliers laterally.

FHWA GEC 12 / GEC 9 · USACE EM 1110-2-2906

Drilled shafts

α / β / rock side resistance, clay / sand / rock tip bearing, exclusion zones, and belled-base uplift.

FHWA-IF-99-025

Shallow footings

General bearing equation with biaxial effective dimensions and full-contact rejection; elastic settlement, base-friction sliding and rotation.

Das / Vesić

Uplift plates & anchors

Shallow and deep breakout in sand and clay, plus grouted-anchor adhesion capacity.

AllPile §8.4–8.5 · Das

Moment–curvature

M–φ and nonlinear EI for solid-circular, pipe and rectangular steel sections by fiber integration — feeds cracked-section lateral runs.

Fiber integration

Slope stabilization

Demand/capacity across trial slip surfaces for an explicit row of stabilizing piles, resolved into lateral and axial components; wide-spacing rows are analyzed independently.

Applied displacement · independent wide-spacing row

Capacity vs length

Axial capacity swept over embedment length — side, tip, downward and uplift curves, with the required length for a target load read off directly.

NAVFAC DM-7.02 swept over L

Torsional capacity

Drilled-shaft shaft/toe torsional capacity plus calibrated monotonic torque–rotation, depth transfer, and service stiffness — for mast arms, signs and other torque-loaded foundations.

FHWA-OR-RD-16-14 Florida District 7 / CDOT

Downdrag / negative skin friction

Neutral-plane analysis under an imposed ground-settlement profile: dragload, neutral plane depth, and the full axial force and settlement profiles.

Fellenius unified · FHWA GEC-12

Foundation stiffness (springs)

Signed reciprocal lateral–rotation tangent matrix plus explicit vertical secant and tangent stiffness at the specified service state.

Exact Winkler matrix · FHWA refined-analysis manual · GEC 12

Pile buckling

First elastic generalized eigenvalue and signed mode with partial embedment, variable EI, explicit end restraints, and mesh evidence.

NCHRP 343 · Davisson & Robinson (1965)

Helical piles

Individual-bearing and cylindrical-shear capacity with per-helix bearing and the AC358 torque correlation.

Perko (2009) · ICC-ES AC358

Rigid and structural pile cap

Explicit load combinations, CPGA-style pile reactions, and AASHTO-2002 flexure, one-way shear, punching, reinforcement, and governing utilization checks.

Saul/USACE CPGA · FHWA NHI-04-041

Nobody is born knowing ε₅₀

Every input explains itself

Each setting carries a little (i) button. Click it for a plain-language definition, why it changes the answer, and typical values — so a first-time user and a seasoned geotechnical engineer both move fast. Try them →

What it is
Why it matters
Typical values
Reference
Soil layer — soft clay
Matlock

↑ These info buttons are live. Click one.

No black box

The same equation LPILE solves — shown, not hidden

PileCalc solves the beam-column-on-nonlinear-foundation equation by finite differences, iterating the secant soil modulus to convergence. You can see the governing equation, the p-y curves, and the node-by-node response behind every result.

Governing equation
EI·y⁗ + Pₓ·y″ + Eₚᵧ·y − W = 0
EI·y⁗
pile flexural resistance
Pₓ·y″
axial load (P-Δ)
Eₚᵧ·y
nonlinear soil reaction
W
distributed load

Discretized by central finite differences into a pentadiagonal system and solved by Picard iteration on the secant modulus Eₚᵧ = p/y until the deflection field converges.

How it compares

The breadth of AllPile. A UI from this decade.

Browser-based lateral analysis exists elsewhere — but no one pairs the full deep-foundation breadth with a modern, explained, shareable workspace.

The full feature-by-feature table is best viewed on a larger screen.

Trust, but verify

Benchmarked against two independent codes

The engine is checked term-by-term against the RSPile theory manuals — matching closed-form and printed-table benchmarks to a fraction of a percent, and chart-published LPILE cases within reading tolerance. Matching two independent implementations — not one — is how you know it isn't reproducing a single vendor's quirks.

Case
PileCalc
Reference
Source
API sand, free head
Head deflection
7.33 mm
7.3 mm
RSPile / LPILE
Dry stiff clay (Welch–Reese)
Head deflection
0.87 mm
0.85 mm
RSPile / LPILE
Fixed-head pile, linear subgrade
Head moment
−581.1 kN·m
−581.0 kN·m
Liang 2014 exact solution
P-delta beam-column, 100 kip axial
Max moment
3,101,232 in·lb
3,101,138 in·lb
Independent code, printed output
Layered soil movement, 5 m slide
Head deflection
41.1 mm
≈ 41 mm
LPILE (Verif. 6)

These are lateral-pile cases; every tool — from axial capacity, drilled shafts, footings, groups, moment–curvature, slope and uplift to torsion, downdrag, buckling, helical piles and the rigid pile cap — is benchmarked the same way. See the full per-tool validation report →

FAQ

Questions, answered

Run your first analysis in the next two minutes.

Open the app, drop in a pile and a soil profile, and watch the deflected shape and moment diagram appear — with every input explained as you go.