ITASCA Software UDEC Logo
Distinct-Element Modeling of Jointed and Blocky Materials in 2D

Redefine geomechanical analysis with UDEC. Designed for 2D modeling of rock and soil behavior, including discontinuities. Perfect for mining, tunneling, and civil engineering projects. Explore new horizons in geomechanics!

Solutions for Various Geotechnical Challenges

What Kinds Of Problems Can UDEC Solve?

Rock slope failure simulation using bonded blocks to represent a rocky slope, including joints for major faults. Blocks are colored by displacement magnitude.

Simulation of stone arch blocks showing vertical stress.

Twin supported tunnels in jointed rock with contours of vertical displacement.

Stored nuclear waste subjected to an earthquake.

Thermal-mechanical simulation of the behavior of a waste emplacement drift in which heat-producing waste is placed vertically beneath the floor.

Groundwater flow through rock joints with flow though intact rock represented by low permeability flow paths between the joints showing the DFN (left) and aperture (right).

Injection rate affects normal opening and shear stimulation of DFNs with various levels of connectivity.

EGS study showing flow localized in a few fracture channels after 30 years of production.

Evaluation of the connectivity using an explicit representation of a Discrete Fracture Network (DFN) to identify clusters and estimate cluster size.

Hydrodynamic analysis of a concrete gravity dam on a jointed rock foundation with Westergaard pressure applied along the upstream face of the dam. Block displacements are shown along with joint pore pressure.

Lined underground drift showing displacements in the rock (represented as Voronoi blocks). Fractures can form between blocks. Axial forces along the liner are shown as bars.

Principal stresses forming around underground mine open stopes.

Simulation of roof collapse behind an advancing longwall coal face. The plot shows displacement contours after 150 m of excavation.

Groundwater flow through rock joints (after 8 hours) with flow though intact rock represented by low permeability flow paths between the joints.

Virtua UCS lab test for a highly jointed sample showing displacement contours (left) and the stress-strain curve (right).


Why Choose UDEC?

Experience the simplicity of 2D discrete element modeling with an intuitive interface and robust capabilities, including the ability to run two instances simultaneously. Discover why UDEC is the ideal choice:

  • Plane strain

  • Axisymmetric (mechanical)

  • Small-strain mechanics (gridpoints remain fixed)

  • Large-strain mechanics (gridpoints move with displacement)

  • Effective stress (pore pressure)

  • Automatic factor of safety

  • Back-analyze failure and calibrate forward-prediction

  • Multiple, simultaneous failure mechanisms

  • Zone relaxation for gradual excavation and construction sequencing and out-of-plane closure

  • Groundwater flow within joints

  • Material flow

  • Synthetic Rock Mass (SRM)

  • Bonded Block Modeling (BBM) for fragmentation and fracturing

  • Service limit state (SLS) and ultimate limit states (ULS) based on displacements

  • User-Defined Contact Models (UDC)

  • Surface subsidence

  • Recovery and dilution

  • Coupled ground-structure interaction (beams, cables, piles, shells, geotextiles, liners)

  • Options available: Thermal, Creep, User-Defined Constitutive Models (UDM), Fluid Flow in Joints, Barton-Bandis Joint Model

  • UDEC modeling uses a combination of interactive tools and commands. UDEC simplifies modeling with interactive features such as CAD file compatibility and built-in mesh generation. Easily construct models interactively, with commands generated automatically to assign constitutive models and properties using the built-in materials database, select boundary conditions, and assign stresses. Models may be constructed and saved in stages. Additional stages may be built from previous ones, making organizing and running parametric studies simple.

  • UDEC utilizes multi-threading and optimized solutions for fast, responsive, and accurate simulations. Users may also run two instances of UDEC on the same computer simultaneously, cutting down on overall time to solution for multiple models.

  • UDEC offers robust hybrid (DEM + continuum) simulation capabilities to model blocks of discontinuous material (jointed rock or masonry bricks). Blocks may be rigid or deformable (zoned) and may slide, rotate, move apart, or come together. Uniquely model groundwater flow within joints and through the ground between them. Couple mechanical, hydro, and thermal solutions. Dynamic analysis to simulate earthquakes and structural elements for ground support are available. Statistical joint set and DFN generation tools are built-in. Advanced plotting tools and FISH scripting provide unparalleled model control and customization, while statistical tools and data import options expand modeling possibilities.

  • UDEC is available in two styles: the original GIIC (interactive modeling tools) and the common UI (advanced graphics, model inspection, and powerful pre/post-processing tools). UDEC 7 data and save files can be readily exchanged by each program. Enjoy flexibility in your workflow to build and modify your models. Use FISH scripting for model parameterization, custom visualizations, adding new physics, and/or model run control. Use one of the 14 built-in elastic/plastic constitutive models, eight creep models, or four built-in contact models for rich material behavior or develop a custom user-defined constitutive/contact model. UDEC licenses allow for two instances to run on the same computer simultaneously. Licenses are also portable between computers using a USB key or web license.

  • In conjunction with interactive tools, UDEC uses commands to provide a compact representation of the model (as a data file) for repeatability, to ensure path dependency (excavation sequence and any other sequence of events, such as boundary conditions or material property changes), for flexibility, and for quality control and project archiving. The built-in text editor adds efficiency to creating and running models with commands. Intuitively structured commands, built-in contextual help, and command auto-completion help users learn and work with commands. Most user interface interactions are automatically translated into commands, so you can see how they are composed and reuse them.

Hear From Those Who Achieved Results with ITASCA Software

See What Users Have to Say

"J'utilise les logiciels [ITASCA], principalement FLAC2D et FLAC3D ainsi que UDEC, depuis plus de 20 ans. Ils m'ont aidé à résoudre des problèmes complexes et m'ont permis de personnaliser la solution grâce à la programmation. Les logiciels [ITASCA] sont mon choix ultime pour les problèmes géotechniques difficiles."
Farzaan Abbasy, PhD
"Les logiciels [ITASCA] comme FLAC3D, UDEC et 3DEC sont très puissants et conviviaux."
Jung Wang, PhD Candidate

Expand Your Software Capabilities With These Options:

Expand your UDEC software capabilities with our range of add-on options, designed to tackle diverse engineering challenges effectively. Explore our selection of options to customize your UDEC experience.
  • UDEC’s thermal analysis allows the simulation of transient heat conduction for modeling geothermal, ground freezing, and nuclear waste applications. Heat sources may be inserted into the material and may be made to decay exponentially with time. Thermal analysis provides one-way coupling to the mechanical stresses plus one-way coupling for fluid flow in joints. Several different thermal boundary conditions are available.

  • UDEC’s creep option can be used to simulate the behavior of materials that exhibit time-dependent material behavior. UDEC provides eight constitutive models for simulating creep, which cover both viscoelastic and viscoplastic behavior. You can also modify these models or create new creep constitutive models using C++ for a user-defined constitutive model (UDM) option. Applications include oil and gas reservoirs, compressed-air energy storage, mining, frozen ground, nuclear waste disposal, and deep tunnels. For some of the creep constitutive models, the creep rate is temperature dependent. Temperatures may be either specified as a model property or calculated during cycling using the Thermal option. For either case, a temperature gradient also may be specified.

  • UDEC’s UDM option greatly expands the software’s versatility by permitting users to create their own contact or material (zone) constitutive model, using C++ scripting. The main function of the material model is to return new stresses with given strain increments. The main function of the contact constitutive model is to return forces with given displacements.

    Templates and instructions are provided. Start by modifying one of the built-in models or create a new material behavior from scratch. UDMs can be automatically loaded into your UDEC project and may be freely distributed (as a DLL file). ITASCA maintains a UDM Library on our website for users to share their UDM models.

  • Analyze fluid flow through fractures and voids between impermeable blocks, and pore pressures can be assigned to zones within deformable blocks with fluid pressure boundary conditions applied or by defining an impervious boundary. A porous medium can be defined around the UDEC block model to simulate a regional flow field.

  • Extends simulation capabilities of UDEC to include the Barton-Bandis joint model, which utilizes a series of empirical relations for joint behavior based on the effects of surface roughness on discontinuity deformation and strength.

  • Extends simulation capabilities of UDEC to include the Barton-Bandis joint model, which utilizes a series of empirical relations for joint behavior based on the effects of surface roughness on discontinuity deformation and strength.


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