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

FLAC3D (Fast Lagrangian Analysis of Continua in 3 Dimensions) is numerical modelling software for geotechnical analyses of soil, rock, groundwater, constructs, and ground support. Such analyses include engineering design, factor of safety prediction, research and testing, and back-analysis of failure.

FLAC3D utilises an explicit finite volume formulation that captures the complex behaviours of models that consist of several stages, show large displacements and strains, exhibit non-linear material behaviour, or are unstable (including cases of yield/failure over large areas, or total collapse).

Perpetual, monthly lease, and annual lease licences are available as either a local USB-key (which is portable), a multiple-seat network USB-key or digital web licence. Academic institutions qualify for special pricing discounts.


Continuum analysis can be applied to engineering design of civil, mining, and geotechnical excavations (e.g., slopes, tunnels, caverns, stopes, etc.) and constructs (dams, foundations, footings, walls, etc.) in soil, intact rock, and rock masses (i.e., heavily jointed rock). Using interfaces, FLAC3D can also simulate discontinuities such as faults, joints, bedding planes, and engineered boundaries along constructs. Consider 3DEC for simulations in blocky ground or if there are many more than 20 discrete faults, joints, or bedding planes in your numerical model.


Options in FLAC3D are sold separately from the general license, allowing users to extend the program’s capabilities as meets their own analysis needs.

Dynamic Analysis: Option for analysing earthquakes, seismicity, and mine rockbursts, for example.

Thermal Analysis: Option for analysing both conduction and advection in materials for nuclear waste disposal and cement hydration, for example.

Creep Analysis: Option for analysing time-dependent material behaviour, for excavations in salt or potash, for example.

C++ Plug-in: An option for building powerful custom functions and constitutive models using C++ scripting. Itasca maintains a library of user-defined constitutive models online.

IMASS:  option to represent the rock mass response to excavation induced stress change.

Further Information

Further information on FLAC3D  is available on the Itasca website including tutorials, features, options, and what's new in FLAC3Dv7.  You can also try the FLAC3D Demo.

Cookie Policy

This site uses cookies to store information on your computer.

Do you accept?