UDEC

UDEC (Universal Distinct Element Code) is a two-dimensional discontinuum code well suited for problems involving jointed rock systems or assemblies of discrete blocks subjected to either quasi-static or dynamic loading.

In addition to the up to 30% speed increase compared to the previous version, UDEC 5.0 has redesigned the graphical user interface (GUI) to be more functional, easier to use and includes all UDEC features available through the command line. A new FISH editor with parameters has been added to the GUI. This makes it easier to include FISH functions in GUI project files. Engineering capabilities have been enhanced: more accurate plasticity solutions using Nodal Mixed Discretization, new Modified Hoek-Brown model, new (and improved) structural elements, gas flow modeling in the fluid flow logic, improved automatic Voronoi joint generator (100 times faster), and more. UDEC's already rich post-processing facilities have been extended in version 5.0 with a number of new plot types and switches.

APPLICATIONS IN THE FOLLOWING FIELDS

• Stability analysis of slopes (factor of safety calculation included), retaining walls, or open pits;
• Study of fractured media or masonry structures subjected to monotonous or cyclic loading;
• Stability analysis of dams on jointed rock foundations under hydraulic and/or dynamic conditions;
• Thermo-hydro-mechanical studies of fractured media in fields as diverse as oil industry, agriculture, pollution control, waste disposal, gas storage, and slope stability.

GENERAL FEATURES

MODEL GENERATION

The discontinuous medium is represented by an assembly of rigid and/or deformable blocks. These latter blocks are made of elements that behave according to stress/strain laws. UDEC 5.0 contains two automatic joint generators that create joint patterns described in terms of angle of joint track to x-axis, trace length of joint segment, gap length between joint segments, spacing normal to joint tracks ... The following commands "arc", "tunnel", "crack" and "jset" allow an easy creation of boundary shapes.

CONSTITUTIVE MODELS

Colour scale vectors of displacement magnitude on a slope.

Several block and joint material built-in constitutive models are provided in UDEC:

Possibility to develop one's own constitutive model in C++ (available as an option). This CPPUDM option also gives access to more than 15 block material constitutive models (Cam-Clay, double-yield, Drucker-Prager, Finn, orthotropic, and creep models).

STRUCTURAL ELEMENTS

They provide the ability to model support.

• Beam elements, used to represent a structural member in which bending resistance and limited bending moments are important (concrete lining, steel sets...).
• Support members, intended to model hydraulic or wooden props or packs.
• Cables, reinforcement elements that cannot sustain a bending moment (nails, rock bolts, cable bolts and tiebacks - pre-tensioned or not).

Cables and beams take into account hydrostatic pressures and heat.

INITIAL CONDITIONS

Certain gridpoint and zone variables can be initialised: stress state, pore pressures, saturation, velocity, temperature, mechanical pressure,...

BOUNDARY CONDITIONS

Certain gridpoint and zone variables can be fixed: stress state, pore pressures, saturation, velocity, temperature, mechanical pressure, absorbing boundaries...

LOADING

• Mechanical: simulation of an excavation, a stress field, a surface load ...
• Hydraulic: modeling of fluid-flow, of two immiscible and slightly compressible fluids and gas-flow through fractured media, possibly coupled to mechanical and thermal processes.
• Thermal: simulation of transient heat conduction in materials and the development of thermally-induced displacements and stresses. The thermal analysis may be coupled to the mechanical and the fluid calculations.
• Creep (option): modeling of the visco-plastic behaviour of certain materials.
• Dynamic: simulation of an earthquake or an explosion.

Colour-scaled displacement vector field in a tunnel model using the improved structural liner. The Axial force on the liner is shown in blue.

Contour of gas pressure in joints surrounding a pressurised cavern

FISH MACRO-LANGAGE

All Itasca codes possess the built-in programming language FISH that allows users to customise their analyses to suit their needs. Loading patterns, servo-control of test conditions and block generation sequences are example uses of FISH.

INTERNATIONAL RECOGNITION

Itasca Consultants, experts in numerical modelling, offer a new vision of numerical solutions thanks to their know-how and software solutions. At the crossroads of consulting and Research & Development, Itasca Consultants provide computer modelling solutions for both the public sector and consulting firms.

ASSISTANCE

Installation and general code operations are provided for free by phone, fax or email. Web site support (www.itascacg.com) includes free code updates and a « Frequently Asked Questions » (FAQ) page.

Training courses, general or tailored to users' needs, are regularly organised by Itasca. Do not hesitate to contact us.

As provider of consulting services, Itasca provides tailored help to solve technical problems and write specific procedures.