Understand every number PileCalc gives you
These docs explain the engineering behind each analysis in plain language — what every input means, why it matters, and the published method it comes from. The info button (i) next to any field in the app links straight to the matching section here.
Getting started
New here? Start with these three.
Introduction
What PileCalc is, the engine behind it, and the philosophy of transparent deep-foundation analysis with public verification evidence.
Quickstart
Run a laterally loaded pile end to end in two minutes, then learn how to read every number it returns.
Units & conventions
PileCalc is unit-agnostic — supply any self-consistent system. Here is how to stay consistent and what every sign means.
Analyses
A deep dive into every analysis — the method, each parameter, and how to read the output.
Lateral (p-y)
The COM624P p-y finite-difference method — pile inputs, every soil model and parameter, head conditions, and how to read the response.
Axial capacity
Side friction and end bearing for compression and uplift, the load–settlement curve, and the factors of safety that govern design.
Capacity vs length
Sweep the embedded length and read off the pile length required for a target axial capacity — the NAVFAC method run at every length.
Torsion
Florida District 7/CDOT drilled-shaft capacity with explicit toe transfer and calibrated monotonic torque–rotation/depth response.
Downdrag
FHWA GEC 12 neutral-plane analysis with layer-specific t-z/q-z transfer, pile self-weight, explicit consolidation or measured settlement, load combinations, and convergence evidence.
Foundation stiffness
Signed reciprocal lateral–rotation tangent stiffness and vertical secant/tangent response at an explicit service state.
Pile groups
Vertical block efficiency and group settlement, and lateral row-by-row p-multiplier shadowing for closely spaced piles.
Structural pile cap
Saul/USACE CPGA pile-load distribution plus edition-specific AASHTO-2002 cap flexure, one-way shear, punching, and reinforcement checks.
Drilled shafts
FHWA-IF-99-025 capacity for bored piles: α / β / rock-socket side resistance, base bearing, and belled-base uplift.
Helical piles
Axial capacity by individual plate bearing vs cylindrical shear, with the per-helix breakdown and the AC358 installation torque.
Footings
The general bearing-capacity equation with every correction factor, elastic settlement, base sliding, and eccentric tilt.
Uplift
Shallow and deep breakout capacity for bearing plates and helices, plus grouted ground-anchor bond capacity.
Moment–curvature
Fiber-integrated M–φ and nonlinear flexural rigidity for solid-circular, pipe, and rectangular steel sections.
Buckling
First elastic buckling eigenvalue and signed mode of a finite, partially embedded pile on linear Winkler support.
Slope stabilization
Strict pile-row demand/capacity checks across declared candidate slip surfaces, with explicit distributed demand and convergence evidence.
Reference
Validation evidence, the HTTP API, and a glossary of symbols.
Validation
How the engine is validated: named sources, the frozen public benchmark manifest, and term-by-term checks against LPILE, RSPile and closed-form solutions.
API reference
Every analysis in the app is a thin layer over a clean HTTP API. Run the engine from your own scripts, CI, or spreadsheets.
MCP & ChatGPT
Connect PileCalc to MCP clients or the official ChatGPT integration with shared paid-plan authentication, quotas, and scientific provenance.
API · Lateral
POST /v1/lateral — request and response fields for the COM624P p-y analysis, with runnable curl, JavaScript, and Python examples.
API · Axial
POST /v1/axial — request and response fields for NAVFAC capacity and the load–settlement curve, with runnable examples.
API · Capacity vs length
POST /v1/capacity-length — request and response fields for the axial capacity-vs-embedded-length sweep, with runnable examples.
API · Torsion
POST /v1/torsion — strict named capacity, calibrated monotonic transfer, service state, convergence, and applicability fields.
API · Downdrag
POST /v1/downdrag — request and response fields for the neutral-plane downdrag analysis, with runnable examples.
API · Stiffness
POST /v1/stiffness — explicit service loads, centered tangent steps, signed reciprocal matrix terms, vertical secant/tangent response, and diagnostics.
API · Buckling
POST /v1/buckling — finite-pile generalized eigenvalue request, convergence metadata, and signed eigenmode.
API · Footing
POST /v1/footing — request and response fields for bearing, settlement, sliding, and eccentric tilt, with runnable examples.
API · Drilled shaft
POST /v1/drilled-shaft — request and response fields for FHWA-IF-99-025 shaft capacity, with runnable examples.
API · Group vertical
POST /v1/group-vertical — request and response fields for group capacity, efficiency, and settlement, with runnable examples.
API · Group lateral
POST /v1/group-lateral — request and response fields for the row-by-row p-multiplier group analysis, with runnable examples.
API · Helical
POST /v1/helical — request and response fields for helical-pile capacity and the AC358 torque, with runnable examples.
API · Group cap
POST /v1/group-cap — explicit load combinations, CPGA pile reactions, and AASHTO-2002 structural cap checks.
API · Uplift
POST /v1/uplift — request and response fields for plate breakout and anchor bond capacity, with runnable examples.
API · Moment–curvature
POST /v1/moment-curvature — request and response fields for the fiber-integrated M–φ analysis, with runnable examples.
API · Slope
POST/GET /v1/slope — strict pile-row candidate-surface demand/capacity analysis with runnable examples.
Excel integration
Run any analysis from a spreadsheet with a generated WEBSERVICE() formula — inputs in cells, results that recalculate live.
Glossary
A quick reference for the symbols, soil parameters, and geotechnical terms used throughout PileCalc.