3DEC Features

3DEC is ideally suited to analyze potential modes of failure directly related to the presence of discontinuous features. Work with either discrete blocks, zoned continuum, or both.
3DEC provides 13 built-in zone material models, three built-in joint models, groundwater flow (solid matrix and joints), coupled mechanical-flow calculation, ground support structural elements, and a built-in scripting language (FISH) that can customize or automate virtually all aspects of program operation, including user-defined properties and other variables.
The software can be extended with four options (dynamic, thermal, Finite Element (FE) liners and blocks, and C++ User-Defined Constitutive Models) that are offered separately from the base program (see Options for more information).
3DEC offers a fully integrated development environment that includes: project management facilities, built-in text editor, automatic movie-frame generation, extensive plotting capabilities, and results monitoring.


  • Analysis of jointed rock and blocky structures based on the Distinct Element Method (DEM)
  • Built-in project management tools, text editor, automatic movie-frame generation, and extensive plotting capabilities,
  • Ideal for modeling large movements and deformations
  • Accurate simulation of fast rotating rigid blocks
  • Blocks may be rigid or automatically zoned (tetrahedral and/or hexahedral) to make deformable blocks
  • Optimized to solve problems requiring non-linear multi-physics
  • 64-bit, double-precision calculations
  • Multi-threaded algorithms with no CPU locks or additional CPU fees
  • Includes groundwater joint fluid-flow
  • Includes groundwater matrix (i.e., permeable solids) fluid-flow between fractures NEW
  • Fluid flow may be either uncoupled or fully coupled hydromechanical
  • Built-in scripting language, FISH, provides powerful user-control to parameterize, analyze, review, and modify nearly every aspect of the simulation, even during cycling
  • Track histories of model properties and results throughout the model to allow for comparison to actual monitoring and instrumentation data

Materials and Constitutive Models

Model Construction

  • Block generation using primitives (face, tetrahedral (NEW), brick, drum, and prism)
  • Bonded block models can be generated based on mesh zones NEW
  • Automatic tunnel region generator using tunnel profile
  • Automatic mesh generation in fully deformable blocks using tetrahedral and hexahedral zones (including mixed-discretization)
  • Easily separate objects into separate geometric regions using geometric surfaces, volumes, or geometry offsets
  • Geometry creation using polygons
  • Results visualization (property/results painting) on DXF or STL geometry
  • Create regions using cubic blocks cut by user-defined outlines (replaces PGEN)
  • Wall-type blocks speed up model runs as motion and wall-to-wall contacts are skipped in solution cycles
  • Built-in block zone densification for hexahedral and tetrahedral (NEW) mesh refinement, including automatic octree generation from surfaces and volumes
  • Built-in ability to assign groups based on counting projection intersections for defining complex groups and ranges for blocks, zones, gridpoints, contacts, and subcontacts:
    • to refine a 3DEC model before identifying a group of blocks as weak material (e.g., faults, damage around an excavation)
    • to assign properties to zones that are inside of some geometric surface that defines a geological unit
    • to define excavation sequences using DXF files representing periodic excavation surfaces
    • to assign different groups to blocks that will be excavated
    • to carve groups out of an existing 3DEC model along multiple surfaces

Joint Sets and Discrete Fracture Networks

  • Joint structures can be built into the model directly from geologic mapping
  • Specify continuous and discontinuous joint sets by orientation, number or spacing, origin, and persistence
  • Random seed values and statistical deviations can be utilized to create multiple realizations (examine sensitivities and risk)
  • Blocks can be hidden (and subsequently restored, similar to a layer) to limit joint cutting or joining
  • Easily define non-persistent joints (e.g., circular) and their properties
  • Blocks can be cut using Discrete Fracture Network (DFN) geometry
  • Incorporate Discrete Fracture Networks (DFNs) by specifying density (e.g., number of fractures per unit distance/area/volume) and orientation-,  size-, and position-distributions for circular disks or polygons
  • Import/export both Itasca circular disk or Fracman polygon DFN data formats







Boundaries and Initial Conditions

  • Discontinuities (interfaces, joints, joint sets, and DFNs) are regarded as distinct boundary interactions between blocks; joint behavior is prescribed for these interactions
  • Stress boundary
  • Applied force (load) boundary
  • Velocity boundaries along Cartesian axes and along a normal direction
  • Structural elements for ground support include: beams, cables, and (optionally) liners
  • Add external infrastructure (such as dams, bridges, walls, buildings, etc.) using finite element structures (optional)
  • Time-varying boundary conditions
  • Couple a detailed inner model to a larger far-field model for increased solution efficiency
  • Define in-situ stresses and stress gradients
  • Includes tools to easily transfer field stresses to model stresses
  • Automatically assign in-situ stresses based on model surface topology, depth, material density, and stress-ratio values NEW
  • Quiet (i.e., non-reflecting) and free-field boundaries (with dynamic option)

FISH Scripting

  • Provides powerful functionality to parameterize, analyze, review, and modify nearly every aspect of the simulation, even during model cycling
  • Built-in text editor provides command syntax error checking and context sensitive help for simpler, faster model generation
  • Intrinsic variables and functions (e.g., cos, round, inverse(matrix), clock, max, sqrt, urand, parse, cross, dot, pi, and more)
  • Control statements (e.g., loop, loop-while, command, if/else-if, case, pause/continue, and more)
  • Intrinsic email functions to automate model notifications and result delivery (e.g., attached plots, history CSV data, and parameter values)
  • Input statements to pass data to and from FISH functions
  • Inline FISH (embed FISH calculations within a command)
  • Extra variables for blocks, zones, gridpoints, contacts, and subcontacts permit user-defined parameters to be applied, computed, or measured for each of these data structures
  • Blocks, zones, gridpoints, contacts, and subcontacts and be filtered by groups. Each data structure may be associated with multiple groups using group slots (similar to layers)
  • Error handling functions
  • Full FISH access to geometric data
  • Model data can be exported as a binary or ASCII file for use in, or exchange with, third-party software
  • Call functions at any stage of a calculation cycle (e.g., start of cycle, when contact created/detected, when sub-contact created/detected, and velocity input) using FISHCALL functions
  • Learn more about FISH

Factor of Safety Analysis

  • Automatic, fast solutions using the shear strength reduction (SSR) method and a converging bracket approach
  • May include strength properties for certain zoned material models and the Mohr-Coulomb joint model
  • Applicable for Mohr-Coulomb, Ubiquitous-Joints, Hoek-Brown, and Modified Hoek-Brown constitutive models
  • Color blocks by excess shear stress or factor of safety for a given hypothetical set of joints NEW

User Interface

  • Similar interface to Itasca's FLAC3D and PFC software
  • Project file and project management tools simplify organizing data files, save files, plots, etc.
  • Associated files in a project can be bundled together into a single file to easily share and archive work
  • Multiple layout configurations and customization are possible
  • Advanced ranging and filtering of model regions
  • Built-in, advanced text editor with command and FISH context coloring
  • Command-level UNDO: a record of all commands used to create a model is recorded in the SAV file, permitting the model to be rebuilt to the previous state
  • Advanced methods of filtering objects (connected to interfaces, on model surface, and by object extent)

Post Processing

  • Extensive visual plotting capabilities, including contouring on blocks, zones, and joint-surfaces; scalar, tensor, and vector plots, 3D isosurface contouring of gridpoint and zone data;
  • Cut-planes, clip-boxes, and transparency settings to assist with engineering analysis and high-quality results plotting
  • Equal area and equal angle stereonet plotting of DFN joint orientations
  • Equal angle stereonet plotting of joint normal orientations and orientations of major, minor, and intermediate principal stresses
  • Export plots as PNG, DXF, VRML, SVG, or PostScript formats
  • Easily export history results to spreadsheet-compatible CSV files
  • Import and export tables, histories, and model variable data to ASCII files
  • Automatically export a series of PNG images at regular cycle intervals to create a video-ready image set (third party software required for video assembly)
  • Ability to export plot views as data files permits favorite views (orientation, plot-items, property settings, etc.) to be saved and restored in the same, or another, model
  • Track and plot fragments (i.e., disconnected groups of blocks) NEW

Responsive Help

  • In addition to an extensive, ten-volume set of physical and PDF manuals, interactive HTML manuals are embedded in 3DEC
  • Contextual help is available. The relevant HTML help section can be accessed for any command or FISH function simply by pressing the F1-key