Changelog

What's new

Fixed
  • Cyclic RCK stiff clay now uses the FHWA GEC 9 Table A-1 representative cyclic modulus default (200 pci) instead of keeping the static 500 pci default; static stays 500 pci. Cycle count N is used only for Welch–Reese under cyclic loading; fixed-branch models stay invariant to N.
  • This is an engineering consistency fix. It is not a PE signoff.
Improved
  • Hitting the Free 1-project cap now offers a 14-day Pro trial at /app/settings/billing?offer=trial (New project, Save to project, and the projects dashboard). Pro and Business are not nagged.
Improved
  • After a successful Free analysis, the in-app summary now offers a 14-day Pro trial at /app/settings/billing?offer=trial instead of a dead-end “Full results are a Pro feature” overlay. Pro and Business are not nagged.
Fixed
  • Vesić tip stratum now uses the bearing layer below a tip-on-interface, instead of the layer above when the tip sits on a layer boundary.
  • Downdrag no longer forwards NAVFAC zeroZones/negativeZones into t-z skin.
  • Group-vertical docs now match the released driven-sand rule: group capacity is n · Q_single with η = 1, not min(individual, block). The equivalent-block check remains a diagnostic.
  • Slope Q-z uses the same tip-on-interface stratum rule as axial Vesić.
  • Cyclic Reese 1975 / Reese-Cox-Koop stiff clay below water now uses yp = 4.1 · As · y50 (original A) even on the cyclic curve. Ac/B still scales peak and residual p only.
  • These are engineering and documentation consistency fixes. They are not a PE signoff.
Changed
  • Pro is $29.99/month ($24.99/month billed annually).
  • Free plan is now 3 in-app analyses per month and 1 saved project, with summary results only.
New
  • One-time Pro trial, 14 days, for eligible new subscribers.
  • Paid MCP and ChatGPT app integration for the same 16 analysis types as the API.
Improved
  • Scientific validation expansion, including public stiffness and buckling benchmarks.
New
  • Lateral pile workflow articles: Excel as a front end to the p-y API, and automation compared with LPILE batch runs and RSPile Python.
Improved
  • Published scientific validation program across the site and registry.
  • Public A/B-coefficient copy now matches the shipped COM624P v2.0 sand A/B and stiff-clay A tables.
Improved
  • UI coverage for every analysis feature, including sectioned and tapered piles, additional head and tip conditions, LRFD combinations, and per-input unit dropdowns.
New
  • Seven more analysis types: capacity vs length, torsion, downdrag, foundation stiffness, pile buckling, helical piles, and pile-cap analysis — 16 tools in total.
  • Show API code and Use in Excel (WEBSERVICE) on every tool, plus a schema-generated API reference.
  • Free SPT correlations calculator (FHWA N₆₀ / (N₁)₆₀ corrections and Caltrans cohesionless ranges).
New
  • Free public calculators (no login): lateral deflection, p-y curves, pile capacity, pile settlement, and group efficiency.
  • Billing moves to Stripe. Business is $99.99/month ($999/year) for teams.
New
  • Browser-generated PDF reports for every analysis type.
New
  • Projects, saved analyses, version history, and audit logs.
New
  • Public REST API on api.pilecalc.com — key-authenticated and plan-gated.
Improved
  • Backend is Clerk + Convex (Convex is the API and database).
  • Per-tool benchmark suite and a public validation page.
New
  • Laterally loaded pile analysis with live deflection, moment, shear and soil-reaction profiles.
  • Axial capacity & settlement with the t-z / q-w load–settlement curve.
  • Info buttons on every input — definition, why it matters, and typical values.
Improved
  • Georgiadis equivalent-depth treatment for layered soil, matching LPILE and RSPile.
  • Validation report published — benchmarks against LPILE, RSPile and closed-form solutions.
New
  • Public launch of the PileCalc engine and API.