Two-dimensional finite-element analysis for geotechnical engineering, in the browser. Build a plane-strain or axisymmetric model from nine editable sample analyses — a twin-bore tunnel, a strutted diaphragm-wall excavation with dewatering, an anchored sheet-pile wall, a strip footing, an embankment on soft clay, a slope, a circular shaft, a pile load test and a geogrid-reinforced wall — set the soil layers and constitutive models, refine the mesh, switch clusters, walls, struts, geogrids, loads and water on and off phase by phase, and calculate. Results come as smooth gradient contours with deformed meshes, plastic points and flow, cross-sections, wall and lining force diagrams, safety factors by strength reduction, hand-method checks, an A3 drawing set and an Excel workbook.
For feasibility, preliminary design and education. Finite-element results are only as good as the soil parameters and the modelling assumptions: calibrate against site investigation and monitoring, and have critical designs independently checked by a qualified geotechnical engineer. The sample projects are synthetic.
What Geotrix FEM does
A two-dimensional finite-element engine for geotechnical engineering that runs in the browser: plane strain or axisymmetric models meshed with 6-node triangles (layer-mapped and graded towards the structures, with ring meshes around tunnels), 3 Gauss points per element and a skyline solver.
Soil models: linear elastic, Mohr–Coulomb (elastic–perfectly plastic, non-associated flow, tension cut-off), a simplified hardening soil (stress-dependent E50 / Eur) and Hoek–Brown rock converted to equivalent Mohr–Coulomb. Drained, undrained A, B and C and non-porous behaviour, with excess pore pressures, K0 or gravity initial stresses and full-dissipation consolidation phases.
Structures: plates (3-node Mindlin beams with axisymmetric hoop stiffness) for diaphragm walls, sheet piles, linings and facings, fixed-end anchors and struts with prestress, tension-only geogrids, line loads and prescribed displacements, thin-layer interfaces with R-inter strength. Staged construction switches clusters, structures, loads and water on and off phase by phase; steady-state saturated–unsaturated groundwater flow gives the pore pressures, discharge and exit gradients; strength (φ–c) reduction gives the factor of safety.
Nine sample analyses you can edit: shallow twin-bore tunnel with stress relaxation and a building, strutted diaphragm-wall excavation with dewatering, anchored sheet-pile wall, strip footing to failure, staged embankment on soft clay, slope stability, axisymmetric circular shaft, pile load test and geogrid-reinforced wall — each checked against hand methods (Prandtl, Vesic, Bishop circle search, Gaussian trough, Peck apparent pressure, α–β pile capacity, hoop thrust, Ka method).
Results with smooth gradient contours, deformed meshes, plastic points, flow arrows, principal directions, cross-sections, wall and lining force diagrams with phase envelopes, anchor and geogrid forces, load–settlement and safety curves, an A3 drawing set and a protected Excel workbook, in AS, ACI, AASHTO, BNBC or BS practice.