Your browser version is outdated. We recommend that you update your browser to the latest version.

FLAC3D is the best solution to solve complex geotechnical problems for three-dimensional analyses of soil, rock, concrete, structural ground support, and groundwater flow. Options can be added to expand analyses (dynamic, creep, thermal, and IMASS) and to create user-defined constitutive models (UDMs). FLAC3D 9 has an improved user interface (UI) and new interactive tools to construct and interpret models easily. FLAC3D provides an incredibly accurate simulation of real-world geotechnical conditions for engineering applications, such as slope stability, underground excavation behavior, and earthquake simulations. Flexible commands and scripting allow for model parameterization, flexibility, customization, and automation.

With FLAC3D, the only modelling limitation is your imagination.

Why Choose FLAC3D?


  • Interactively create models from CAD files (DXF, STL), sketching, or images
  • Automatic structured and unstructured mesh generation
  • Extrude linearly and along curves NEW
  • Skinning to automatically identify model boundaries to set boundary conditions
  • Interactively assign groups, constitutive models, and properties/distributions
  • Built-in database to save/import/export material properties NEW
  • Automatic stress initialization
  • Intuitive commands are easy to learn
  • Most UI interactions are automatically translated into commands, which can be saved to a datafile and re-used
  • Built-in help / command auto-complete
  • Advanced built-in text editor makes creating and running models simple
  • With Version 9’s common UI, seamlessly move between programs or easily couple to other Itasca software


  • New solution optimization enables 2-3 times faster static modelling and dynamic time steps up to 2.6 times larger than before NEW
  • Multi-threaded to utilize the full power of your computer for faster solutions
  • Multi-threaded FISH Lists and Operators to query or modify the model incredibly quickly, even while cycling
  • New Maxwell damping for 10-200x faster performance for dynamic models NEW
  • Faster implicit solvers for fluid flow and thermal calculations NEW
  • Fast analytical temperature calculation for specified sources NEW


  • Large-strain simulations to capture the full extent of model deformation
  • Includes 27 built-in constitutive models:
    • Null
    • Elastic
    • Orthotropic Elastic
    • Anisotropic
    • Druker-Prager
    • Mohr-Coulumb
    • Ubiquitous-Joint
    • Ubiquitous-Anisotropic IMPROVED
    • Strain-Softening/Hardening
    • Double-Yield
    • Modified Cam-Clay
    • Swell
    • Bilinear Strain-Softening/Hardening Ubiquitous-Joint
    • Hoek-Brown
    • Hoek-Brown-PAC
    • CYSoil
    • CHSoil
    • Plastic-Hardening IMPROVED
    • Mohr-Coulomb-Tension
    • Soft-Soil
    • Finn
    • NorSand
    • P2PSand
    • IMASS (option)
    • Von-Mises NEW
    • Columnar-Basalt NEW
    • Concrete NEW
  • Non-linear deformable ground support elastic and elastoplastic NEW structures
  • Advanced plotting tools to understand your model results and for working with hundreds of plots on real projects NEW
  • FISH, Itasca’s scripting language, provides unparalleled control over, and customization of, the model
  • Built-in Python 3.10 scripting includes SciPy for plotting, NumPy for computing, and Pyside for UI customization
  • Statistical generation tools for Discrete Fracture Networks (DFNs)
  • All model changes (via mouse, commands, or scripting) are recorded for repeatability, learning, and re-use
  • Import pore pressures values to gridpoints from MINEDW .mdp or CSV files (x, y, z, pore pressure) NEW


  • Highly customizable UI NEW and modelling
  • All licenses permit two instances of FLAC3D to be run on the same computer
  • Access and modify almost all variables (including “EXTRA” variables for zones, piles, gridpoints, etc.) via FISH/Python
  • Import and export any ASCII data format
  • UDMs can be written in C++ using Visual Studio template


  • Static and dynamic stability
  • Automatic factor of safety analysis (shear strength reduction method)
  • Back-analyse failure and calibrate forward-prediction
  • Parametric studies via FISH or Python
  • Service limit state (SLS) and ultimate limit states (ULS) based on displacements
  • Automatic zone relaxation simulates gradual excavation for construction sequencing
  • Simulate material damage and failure
  • Effective stress using conventional or complex pore pressure distributions
  • Fluid flow, seepage, and consolidation
  • Coupled ground-structure interaction (beams, cables, piles, shells, geotextiles, liners)
  • Simulate discontinuities (faults, joints, bedding planes, and construction boundaries) using interfaces; capture yielding or failure, shear displacements, opening, and closure along them
  • Static and dynamic liquefaction


Options in FLAC3D are sold separately from the code license, allowing users to extend the program’s capabilities as meets their own analysis needs. Modules available as options for FLAC3D include: IMASS, Dynamic, Creep, Thermal, and C++ Plug-ins for creating and running custom constitutive models and FISH intrinsic functions.


Further Information

Further information on FLAC3D  is available on the Itasca website including tutorials and what's new in FLAC3Dv9.  You can also try the FLAC3D Demo or request a quotation here.

Cookie Policy

This site uses cookies to store information on your computer.

Do you accept?