Open source · AGPL-3.0 · Python
SlipSurface IQ is a family of ten geotechnical engineering programs for slopes, rock, foundations and retaining structures. They share one architecture: driven from your browser, bilingual in English and Turkish, reporting to PDF, HTML and Word, and tested against closed-form solutions.
$ pip install git+https://github.com/hdaltuntas/slipsurface
$ slipsurface
SlipSurface IQ 0.3.1 — http://127.0.0.1:8770/
$ slipsurface bearing run project.bearing
Bearing capacity by method
Terzaghi (1943) q_ult = 516.8 kPa
Meyerhof (1963) q_ult = 466.0 kPa
Brinch Hansen (1970) q_ult = 474.2 kPa
Vesić (1973) * q_ult = 533.5 kPa
EN 1997-1 Annex D q_ult = 517.3 kPa
Sliding: FS = 5.33 ≥ 1.50 — OKOpens in your browser; your data never leaves your machine.
Each tool does one job in depth; together they cover the geotechnical design of a whole project.
Finite elements and limit equilibrium.
2D finite element analysis
2D finite elements for slopes, embankments and deep excavations: factor of safety by strength reduction, staged construction, internal forces in walls and piles, sections and construction sequence straight from DXF.
$ slipsurface-2dLimit equilibrium slope stability
Method-of-slices stability of slopes and embankments: eight methods from Fellenius to Morgenstern-Price, critical surface search, water, seismic, reinforcement and tension cracks — with zero dependencies.
$ slipsurface-leRock mass strength and rock slope kinematics.
Rock slope kinematics and stability
Markland screening on a stereonet and Monte Carlo probability of failure, then wedge, planar and toppling limit equilibrium, bolt design and PDF reports — in one workflow.
$ slipsurface-kinematicRock mass strength after Hoek–Brown
mb, s and a by the generalised Hoek–Brown criterion; the equivalent c′ and φ′ of a tunnel, a slope or a general case; the rock mass modulus; GSI from five classifications; σci and mi fitted to triaxial tests; residual strength.
$ slipsurface-rockShallow foundation capacity, settlement and piles.
Bearing capacity of shallow foundations
Terzaghi, Meyerhof, Hansen, Vesić, EN 1997-1 and Skempton side by side; eccentric and inclined loads, layered ground, SPT/CPT/pressuremeter, rock, earthquake and reliability studies.
$ slipsurface-bearingSettlement of foundations and embankments
Boussinesq and 2:1 stress distribution, Steinbrenner and Schmertmann immediate settlement, primary consolidation and secondary compression, Terzaghi time–settlement and angular distortion checks.
$ slipsurface-settlePile capacity, groups and settlement
Shaft friction by the α, β and λ methods, Meyerhof/Vesić/Janbu base resistance, group efficiency and block failure, compression and uplift under seismic loading, required length, single and group settlement; rock sockets by twelve correlations.
$ slipsurface-pileSheet pile walls, reinforced soil and cantilever concrete walls.
Sheet pile wall analysis
Free-earth support limit equilibrium and staged Winkler beam-spring analysis side by side; Mononobe-Okabe seismic pressures, tension-only anchors and reliability studies.
$ slipsurface-spwaMechanically stabilised earth walls
External and internal stability per FHWA-NHI-10-024 and AASHTO LRFD 11.10: sliding, overturning, bearing, tensile, pullout, connection; steel strips and geosynthetics, corrosion, earthquake, ASD or LRFD.
$ slipsurface-msewCantilever retaining wall design
Earth pressure by four methods, sliding, overturning, bearing and global stability; earthquake by TBDY 2018; TS 500 reinforced concrete design, the reinforcement drawing, DXF and bar schedule.
$ slipsurface-wallNew members of the family; they join the list above when they are released.
Tunnel analysis
Analysis and design of tunnels and underground excavations.
In developmentLiquefaction assessment
Assessing the liquefaction potential of soils during earthquakes.
In developmentSoil parameter correlations
Estimating soil parameters from field and laboratory tests by published correlations.
In development3D geotechnical analysis
Three-dimensional analysis of geotechnical problems.
In developmentLearn one and you know them all. Same interface layout, same files, same commands.
The interface is a small HTTP server on your own machine. It works over a remote session, in a container and on a headless server.
Every label, result, figure and report in English and Turkish; switch while it runs — the numbers never change.
PDF, self-contained HTML and Word reports come from one assembly, so all three say the same thing.
Inputs are saved as readable JSON. A case set up in the browser re-runs unattended from the command line.
Sweep any input as a range or a distribution: LHS, Monte Carlo, sensitivities, probability of failure and β.
Every method is pinned with pytest against published tables, hand calculations and closed-form solutions.
One engine — click through it in the browser, drive it from the command line, or script it from Python.
Follow the design of an excavation, a fill, a piled foundation and an anchored wall on a port site end to end, with the right SlipSurface IQ tool at every step.
Go to the end-to-end example →Python 3.10+ and a single pip command.
Installation guide →