Define the model
Draw the soil regions, water table and structural elements; assign material sets with Mohr–Coulomb, Hardening Soil or HS small parameters.
KATAI 2D · Version 0.2 · In active development
Geotechnical finite element analysis,
built in the open.
A 2D finite element platform for soil and structure — Mohr‑Coulomb and Hardening Soil, consolidation, seepage, supported excavations and slope stability. Every result is checked against the analytical truth, and the formulation is open for you to read.
No credit card. No spam. We are gauging demand — pricing comes later.
1.1% error on the Prandtl bearing capacity factor Nc = 2+π
<2% on the Terzaghi 1D consolidation curve
10−5 relative error on the Lamé thick-cylinder stress field
89/89 automated verification checks pass on every build
The platform, up close
See KATAI 2D in action.
A complete pre-processing, solution and post-processing workflow in one desktop application.
Results you can defend
Every analysis returns more than a pretty picture. Contoured displacement and stress fields are drawn on the deformed mesh, with a colour legend keyed to the true value range.
- Displacement, effective stress, pore pressure and structural force fields
- Extreme-value tables and a point inspector for any node
- Print-ready engineering report (HTML → PDF) with your title block
Meshing that adapts to the problem
Generate a quality unstructured mesh from your geometry in one click, then refine exactly where the physics demands it — around walls, piles and loads.
- Six- and fifteen-node triangles (linear and quartic)
- Local refine / coarsen and automatic refinement around structures
- Live quality statistics — minimum angle and mean shape quality
Model the whole support system
Soil rarely stands alone. Add the structural elements of a real project and build it in the sequence it is actually constructed.
- Plates, anchors, geogrids and embedded beams (pile rows)
- Zero-thickness Coulomb interfaces for soil–structure slip
- Multi-phase staged construction with stress carried forward
Inside the workspace
A closer look at how it reads.
A few panels from the desktop application — material sets, the phase explorer and the point inspector — so you can judge the workflow before there is anything to download.
Stiff clay HS small
- E₅₀℅ₙ
- 40 000 kN/m²
- Eₒₑₐₙ
- 40 000 kN/m²
- Eᵘᵣ℅ₙ
- 120 000 kN/m²
- power m
- 0.55 —
- c′ₒ₋ₛ
- 5.0 kN/m²
- φ′
- 32.0 °
- ψ
- 2.0 °
- γ₋ₐₜ
- 20.0 kN/m³
DrainedRᵢₙₜᵣₕ 0.67
- 1 Initial K₀ procedure
- 2 Wall + dewatering Plastic
- 3 Excavate to −3 m Plastic
- 4 Install strut Plastic
- 5 Excavate to −6 m Consolidation
ΣMstage 0.74
- Node
- #4 217
- x, y
- 12.40, −5.85 m
- |u|
- 38.6 mm
- σ′ₙₙ
- −142.7 kN/m²
- σ′ₓₓ
- −61.3 kN/m²
- p₋ₐ₊ₑ₋
- 11.4 kN/m²
Why KATAI
The numbers, not the marketing.
Commercial geotechnical codes are powerful — and closed. The precise numerics behind a result are not yours to inspect. KATAI 2D is built on the opposite principle: an open formulation, and results that are reproducible to a stated tolerance.
Every capability is locked to its mathematical source — a journal paper, a standard monograph, or the published theory of the established codes — and is then verified against a closed-form solution before it is considered finished. Agreement is never manufactured: where a result is sensitive to mesh or to a known limitation of the theory, we say so.
Workflow
From sketch to verified result.
A familiar, four-step pre-processing → solution → post-processing flow — nothing to script, nothing hidden.
Generate the mesh
One-click unstructured meshing with 6- or 15-node triangles, then local refinement where it matters — with live quality statistics.
Run the analysis
Choose the initial stress, then K₀, gravity, plastic, safety, consolidation or a multi-phase staged sequence — solved on a fast sparse direct core.
Interpret & report
Read the contoured fields, inspect any point, check the structural force diagrams, and export a print-ready engineering report.
Platform
Everything a 2D geotechnical model needs.
Plane-strain and axisymmetric analysis with a single, verified numerical core.
Constitutive models
Linear Elastic, Mohr‑Coulomb with an exact principal-stress return mapping, and Hardening Soil with optional small-strain stiffness (HS small).
Higher-order elements
Six- and fifteen-node triangles. The quartic element captures collapse mechanisms on coarse meshes — Prandtl Nc to 1.1% on 120 elements.
Groundwater flow
Steady-state confined and unconfined seepage with seepage faces, verified by manufactured solutions at the theoretical convergence orders.
Consolidation
Coupled Biot consolidation with a linear-elastic or elastoplastic skeleton, reproducing the classical Terzaghi curve below 2%.
Structures & interfaces
Plates, anchors, geogrids, embedded beams (pile rows) and zero-thickness Coulomb interfaces — for supported excavations and reinforced soil.
Slope stability
Factor of safety by strength reduction (φ‑c reduction), with the failure mechanism localised along the slip surface.
Staged construction
Multi-phase excavation, fill and installation with stress carried forward between phases — the real sequence of a real project.
Fast by design
A sparse direct solver with pattern-aware factorisation and parallel assembly — engineered for the repeated solves of staged and time-dependent analysis.
Applications
Engineered for real geotechnical work.
The analyses that make up the majority of day-to-day practice — on one verified numerical core.
Supported excavations
Retaining walls, anchored and strutted excavations, with staged dewatering and construction sequencing.
Shallow & deep foundations
Bearing capacity, settlement and load–displacement of footings, rafts and pile rows in plane strain or axisymmetry.
Slope stability
Factor of safety by strength reduction (φ–c reduction), with the failure mechanism resolved along the slip surface.
Seepage & dewatering
Steady-state confined and unconfined groundwater flow, seepage faces, uplift and flow-to-deformation coupling.
Embankments & consolidation
Staged fill on soft ground with time-dependent Biot consolidation and excess pore-pressure dissipation.
Shafts & axisymmetry
Circular shafts, tanks and cylinder problems modelled rigorously in axisymmetric (r–z) geometry.
How it compares
The same theory. A different contract.
KATAI 2D targets the analyses that make up most of geotechnical practice with the same accepted theory as the established commercial codes. Those codes are mature and capable — and closed. Our distinction is an open formulation and a result that is verified, openly, on every build.
| Capability | KATAI 2D | Established 2D codes |
|---|---|---|
| Mohr‑Coulomb with exact principal-stress return mapping | ● | ● |
| Hardening Soil & small-strain stiffness (HS small) | ● | ● |
| Biot consolidation with an elastoplastic skeleton | ● | ● |
| Confined & unconfined steady-state groundwater flow | ● | ● |
| Plates, anchors, geogrids, embedded beams & interfaces | ● | ● |
| Strength-reduction (φ‑c) safety analysis | ● | ● |
| Multi-phase staged construction | ● | ● |
| Plane-strain & axisymmetric geometry | ● | ● |
| 6- and 15-node triangular elements | ● | ● |
| Open, published formulation — read the numerics | ● | ○ |
| Per-result verification re-run on every build | ● | ◐ |
| Transient & unsaturated groundwater flow | ◐ | ● |
| Three-dimensional analysis | ○ | ● |
| Decades of project track record | ◐ | ● |
We state what is not there yet, plainly. KATAI 2D is two-dimensional by design and version 0.2 is in active development — the gaps above are on the roadmap, not hidden.
Verification & Validation
Every claim is backed by a test.
A selection from the automated suite that runs on every build of the platform.
| Benchmark | Reference | Result |
|---|---|---|
| Prandtl strip footing Nc (φ = 0) | 2 + π | 1.1% |
| Reissner Nc (φ = 20°) | (Nq−1)cotφ | 2.0% |
| Lamé thick cylinder (axisymmetric) | Lamé | 10−5 |
| Terzaghi 1D consolidation U(Tv) | Terzaghi series | < 2% |
| Radial (Thiem) flow discharge | Thiem | 10−6 |
| Manufactured-solution convergence | Roache MMS | O(h³) / O(h⁵) |
| Slope factor of safety | Bishop / Griffiths & Lane | 2.0% |
| Embedded beam ultimate capacity | skin + base | 0.1% |
Where no closed-form solution exists, results are required to fall within the band of the established commercial codes.
See the full verification record PLAXIS 2D benchmarks · the GUI compute path · speed & robustness
Scientific Manual
Read the formulation. All of it.
The complete theoretical and numerical basis of the platform — the continuum boundary-value problem, the element technology, the constitutive integration, the global solver, flow and consolidation, and the full verification evidence — is documented in a 38‑page Scientific Manual, released for academic and professional review.
Get the manual with early accessAbout
KATAI Geotechnical Engineering.
KATAI Geotechnical Engineering develops KATAI 2D, a finite element platform for soil and soil–structure analysis. We build computational geotechnics the way we believe engineering software should be built: on established theory, with an open formulation, and with every result verified against a known solution before it ships.
Our aim is a tool a practising engineer can trust and a researcher can scrutinise — accurate enough to rely on, transparent enough to defend in a review or an expert report.
- Formulation locked to journal papers, standard monographs and published code theory
- An automated verification suite that runs on every build of the platform
- Honest reporting — known limitations and sensitivities are stated, not hidden
Early access
Be first in line.
KATAI 2D is in active development. Register your interest and you will be among the first invited to use it. We are measuring demand — there is no payment and no commitment.
FAQ
Questions, answered.
What is KATAI 2D?
KATAI 2D is an open-formulation, verification-driven two-dimensional finite element platform for geotechnical engineering. It analyses deformation, stability, groundwater flow and consolidation of soil and soil–structure systems in plane-strain and axisymmetric conditions.
Is it an alternative to the established commercial codes?
It targets the same analyses that constitute the majority of geotechnical practice — supported excavations, foundations, slopes, seepage and consolidation — using the same accepted theory (Mohr–Coulomb, Hardening Soil, Biot consolidation). Its distinction is that the formulation is open and every result is independently verified against the analytical solution.
Which analyses and material models are supported?
Linear Elastic, Mohr–Coulomb and Hardening Soil (with small-strain stiffness); initial K₀ stress, gravity loading, plastic, strength-reduction safety, consolidation and multi-phase staged construction; steady-state confined and unconfined groundwater flow; and structural elements (plates, anchors, geogrids, embedded beams) with Coulomb interfaces.
How accurate is it?
Capabilities with a closed-form solution are reproduced to within engineering tolerance — for example the Prandtl bearing capacity factor to 1.1%, the Terzaghi consolidation curve below 2%, and the Lamé elastic field to a relative error of 10⁻⁵. Each of these is an automated test that runs on every build.
When will it be available, and how much will it cost?
KATAI 2D is in active development (version 0.2). Early access is opening to registered users first. Pricing has not been set — registering now simply puts you in line and helps us gauge demand.
What platforms does it run on?
The desktop application currently targets Windows. Early-access registrants will be informed as availability expands.