3DEC - Optional features


This option models the full dynamic response of a system in the time domain. Capabilities added to standard3DEC include: specification of velocity or stress-wave input; quiet boundaries; free-field conditions; and damping (mass-proportional, stiffness-proportional, and Rayleigh). Problems such as seismic loading, explosive loading, seismic release of energy, and flow of particles may be modeled.

Full and sectioned views of a tower modeled for stability using the dynamic option.


Effects of heat sources embedded in a material are modeled with this option. Point heat sources may be placed individually, in lines, or in grids, to represent point, line, or plane sources of heating. This formulation yields rapid calculations, correct application of mechanical boundary conditions, incorporation of the infinite thermal boundary, and the ability to use inhomogeneous and anisotropic mechanical properties.

A repository drift with temperatures on a section.

Structural Elements

Modeling cables and beams is part of the standard functionality of 3DEC. This option adds the ability to model tunnel liners and external structures (such as dams, bridges, walls, buildings, etc.). The tunnel liner logic automatically places equally spaced triangular-shaped plates on the inside surface of an excavation or tunnel. External structures can be modeled using finite elements that are attached to the 3DEC model.

Model of dam structure using finite element blocks.


User-defined constitutive models can be written in C++ and compiled as DLL files that can be loaded whenever needed with this feature. A Visual C++ Version 6.0 compiler is used to compile the DLL files. This permits exchange of constitutive models among 3DEC users. Models may be shared with other Itasca codes that contain this feature (FLACFLAC3DUDEC). New DLL models can be obtained from the Itasca web site devoted specifically to model development and exchange: www.itasca-udm.com.