Introduction to PileCalc

PileCalc is a modern, browser-native suite for the analysis of deep foundations — laterally loaded piles, axial capacity, pile groups, drilled shafts, shallow footings, uplift anchors, and the structural section behavior that ties them together. It does the same engineering as the established desktop programs (LPILE, AllPile, RSPile, GROUP, SHAFT) but runs anywhere, explains itself as you work, and is validated against those very tools.

What PileCalc is

At its heart PileCalc is a geotechnical solver wrapped in a clear interface. Every screen is built around one idea: you should never have to guess what a number means. Each input carries an info button (i) that explains what the setting is, why it changes the result, and what a typical value looks like — and that button links straight into these docs for the full derivation.

It is built for the engineer who knows the methods but is tired of dongles, Windows-only installs, and 1990s UIs — and equally for the student or early-career engineer who wants to understand why a pile deflects the way it does, not just read a number off a chart.

The engine

Underneath the interface is a single analysis engine implementing the published methods of the profession:

• Lateral response by the COM624P p-y finite-difference method (Wang & Reese, FHWA-SA-91-048), with the Matlock, Reese, Welch & Reese, API / O'Neill–Murchison, and Reese weak-rock p-y models.
• Axial capacity & settlement from NAVFAC DM-7.02 static methods with t-z / q-w load transfer and Vesić (1977) settlement.
• Drilled shafts by FHWA-IF-99-025 (O'Neill & Reese, 1999).
• Shallow footings by the general bearing-capacity equation (Meyerhof / Vesić factors) with settlement, sliding, and eccentric tilt.
• Groups, uplift, moment–curvature, and slope stabilization built on the same primitives.

What you can analyze

The app exposes the full engine through eight analyses:

• Laterally loaded piles (p-y) — deflection, moment, shear, and soil reaction with depth.
• Axial capacity & settlement — compression and uplift capacity plus the load–settlement curve.
• Pile groups — vertical efficiency and lateral p-multiplier shadowing.
• Drilled shafts — α / β / rock-socket side resistance, base bearing, belled uplift.
• Shallow footings — bearing, settlement, sliding, tilt.
• Uplift plates & anchors — breakout and bond capacity.
• Moment–curvature — nonlinear EI of the section.
• Slope stabilization — pile resistance against a moving slope.

How an analysis flows

Every analysis follows the same path. You describe the pile or footing and a layered soil profile, set the loading and a few solver options, and run it. The request is validated against a strict schema, sent to the engine, and the response comes back as both summary quantities and full depth profiles you can chart or export. Because the contract is a clean HTTP API, the exact same analysis can be driven from your own scripts — see the API reference.

Transparent by design

Validation does not remove engineering judgment, and PileCalc never pretends otherwise. The p-y method has limits, soil parameters carry real uncertainty, and you remain responsible for reviewing results for design. PileCalc's job is to make every assumption and intermediate value visible — so that review is actually possible — and then to get out of your way.

Where to go next

• Quickstart — run your first analysis in two minutes.
• Units & sign conventions — read this before you trust a number.
• Laterally loaded piles — the most-used analysis, explained end to end.