News Article

3DEC 9 Officially Released

ITASCA introduces 3DEC v9: Advanced modeling solutions for addressing challenging geomechanical problems in three-dimensional analyses of rock, soil, concrete, nonlinear structural ground support, and groundwater flow.

MINNEAPOLIS, MINNESOTA – January 23, 2024 – ITASCA has announced the release of 3DEC v9, an advanced hybrid discontinuum and continuum modeling tool designed to solve even the most difficult geotechnical challenges in mining, civil, and energy engineering.

3DEC v9 builds on over four decades of ITASCA's expertise in geomechanical software research and development. As a part of ITASCA's suite of industry-standard software products, which includes FLAC3D, FLAC2D, UDEC, PFC Suite, XSite, MassFlow, MineDW, and Griddle, this release is tailored to address geomechanical engineering issues in slope stability, underground excavation, tunneling, ground-structure interaction, and earthquake simulation.

3DEC v9 offers a significant performance boost, with speeds up to 10 times faster than its predecessor. This version introduces advanced computational modeling techniques, an upgraded user interface, enhanced Python support, and compatibility with partner products. The software now supports additional constitutive models, such as concrete, Von Mises, and Columnar Basalt, bringing the total number of supported constitutive models to 18. Notably, this version includes improvements to bonded block modeling (BBM), which is now both faster and easier. The contact detection between blocks enables sliding, opening, closure, rotation, and even complete separation, accompanied by improved joint logic.

According to Jim Hazzard, ITASCA's Director of Product Development, "3DEC v9 enhances both the capabilities and performance of geomechanical modeling. It serves as a powerful geomechanical analysis tool meticulously crafted to fulfill the needs of today’s engineers, offering a comprehensive set of robust modeling methods and strategies."

Delving into the enhanced features, Hazzard explains, "Significant improvements have been made to calculation efficiency so that models will reach a steady state solution significantly faster, dynamic timesteps will be noticeably larger, and plotting is much more responsive."

"The incorporation of nonlinear structural elements and a dedicated constitutive model for concrete in 3DEC v9 facilitates the simulation of intricate ground-structure interactions. This capability enables a more authentic assessment of performance and failure mechanisms, enhancing the capacity of civil engineers to simulate geotechnical conditions that mirror real-world projects."

Charles E. Fairhurst, CEO of ITASCA International Inc. (III), states, "3DEC v9 integrates the most recent advancements in geomechanics computational modeling, featuring optimizations that enhance performance and robustness. With improved usability and computational methods, this empowers engineers in the field, enabling them to address geomechanical problems—ranging from mundane to challenging—with speed and ease."

3DEC v9 is built upon a common framework, meaning that it shares a common look and feel with other ITASCA software, as well as many common components (e.g., structural elements, constitutive models, discrete fracture networks). 3DEC v9 also enables built-in mechanical coupling with FLAC3D, streamlining complex engineering modeling, reducing overhead, and simplifying project management. This results in a potent modeling suite that simplifies work across a broad spectrum of engineering simulations.

3DEC Version 9 is now available for purchase for Windows and Linux. For more information, including detailed product features, pricing, and licensing options, visit


ITASCA is an employee-owned, engineering software development and engineering-consulting company with offices worldwide. It is one of the world leaders in engineering design and numerical modeling of geomechanics and hydrogeology related to mining, civil engineering, and energy extraction. ITASCA blends local experience with a global perspective and maintains an internationally diverse team of leading engineers, software developers, and scientists.

Headquartered in Minneapolis, Minnesota, ITASCA manages ten global offices and over 200 employees. Together, we strive to deliver functional, actionable, and long-term sustainable solutions from an environmental and societal perspective.

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Press Contact: James Arth, Director of Marketing,

This model of a supported tunnel (using hybrid bolts) in jointed rock now solves 10x faster for steady-state conditions. Dynamic modeling time steps are now 3x larger.  
Collapse mechanism for an ancient stone masonry tower subjected to seismic forces.
Flemish wall made up of bricks after being subjected to 5.25 seconds of ground motion.
Existing joints remain joined after additional cutting.
Bonded block models (BBMs) can be constructed using randomly sized tetrahedra and vertex-to-vertex contacts can be suppressed for increased modeling efficiency. Contours of displacement and fracturing (black lines) are shown.
The 3DEC v9 user interface is even more flexible and efficient for working with models and understanding results.
Left: Uniaxial strength tests of the new 3DEC Concrete plastic-damage constitutive model compared to experimental lab tests demonstrates the accuracy of ITASCA numerical simulations. Right: Simulated two-point beam test of steel reinforced concrete.
Cut-away view of a large tunnel supported with cables and a liner passing near a shaft in jointed rock. The tunnel was excavated in a series of top, middle, and bottom cuts followed by staged ground support installation.
3DEC v9 models can now be coupled with FLAC3D v9. A 3DEC bonded block model (BBM) is shown above couple to an outer region of FLAC3D zones.
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