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SIGMA/W on Intel processors provides proven performance
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SIGMA/W is a finite element software product that can be used to perform stress and deformation analyses of earth structures. Its comprehensive formulation makes it possible to analyze both simple and highly complex problems. For example, you can perform a simple linear elastic deformation analysis or a highly sophisticated, nonlinear elastic-plastic effective stress analysis.
The many constitutive soil models allow you to represent a wide range of soils or
structural materials. In addition, when coupled with
SEEP/W,
SIGMA/W can model the pore-water pressure generation and dissipation in a soil structure in
response to external loads.
These features enable SIGMA/W to analyze almost any stress or deformation
problem you will encounter in geotechnical, civil, and mining engineering projects.
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Defining a Stress and Deformation Model
The unique CAD-like technology in SIGMA/W allows you to generate your finite element mesh by drawing regions on the screen. You can then specify material properties and interactively apply boundary conditions, structural elements, trusses, and fill or excavation layers. If you make a mistake, you can correct it using the Undo command.
Viewing the Analysis Results
Once you have solved your problem, SIGMA/W offers many tools for viewing results. View a deformed mesh or displacement vectors at any magnification. Generate contours or x-y plots of more than 30 computed parameters, including deformation, total and effective stress, strain and pore-water pressure. Display shaded yield zones. View the stress state at any node or element Gauss point as a Mohr Circle with the associated space-force diagrams. Plot shear or moment distribution along structural elements. Then export the results into other applications, such as Microsoft Excel or Word, for further analysis or to prepare presentations.
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Use SIGMA/W stresses in
SLOPE/W
or QUAKE/W
Using finite element computed stresses in SLOPE/W makes it possible to conduct a rigorous stability analysis using the same stress values resulting from the deformation analysis. In addition, you can use SIGMA/W stresses as the initial stress state for a dynamic earthquake analysis in QUAKE/W.
Use SIGMA/W pore-water pressures in
SLOPE/W
or SEEP/W
Excess pore-water pressures generated by static loading, such as fill placement, can be brought into SEEP/W to study how long it takes to dissipate the excess pressures in the foundation. You can use SLOPE/W to analyze the effect of these excess pressures on stability during construction, allowing you to determine the need for staged loading.
Click for a complete
 Product Integration Chart
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SIGMA/W 2007 is part of GeoStudio 2007,
an integrated tool containing GEO-SLOPE's leading suite of geotechnical modeling software products:
SLOPE/W, SEEP/W, SIGMA/W, QUAKE/W, TEMP/W, CTRAN/W, AIR/W and VADOSE/W. Using GeoStudio means you can run all of these products
in one environment, creating one model definition that is shared among all products.
For example, when you create your geometry and material properties in one product, they are available immediately in all
other products. Your model is stored in one definition file, which is based on the industry-standard XML format. Sharing the data lets
you run many analyses on the same problem. You can use the results from one analysis in another, or import files created by
previous versions of the software.
SIGMA/W can model almost any stress or deformation problem, including:
- Settlement of footings, fluid-filled tanks, or earth structures
- Deformation within or underneath an embankment or earth dam
- Closure around a tunnel
- Lateral movement of braced or anchored excavations and surface settlement around the excavation
- Floor rebound of open-pit, sloping excavations
- Volume changes (uncoupled consolidation or heave) resulting from pore-water pressure changes
- Staged fill placement, earth removal
- Soil-structure interaction, including free un-bonded anchors, cross excavation struts, and trusses
- Fully-coupled consolidation analysis
- Simulation of tailings deposition
- Permanent deformations resulting from strength loss
- Strength reduction stability
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- Analysis types include drained total and effective stress, undrained total and effective stress, 2D plane strain, 3D axisymmetric, consolidation and swelling, and insitu stress.
- Constitutive soil models include linear-elastic, anisotropic linear-elastic, nonlinear-elastic, elastic-plastic, and Modified Cam-clay.
- Boundary condition types include X and Y displacements, forces, pressures, and spring constants, as well as self-weight gravity loading.
- Structural beam and bar elements for soil-structure interaction.
- Staged loading for fill placement or earth removal.
- Un-coupled volume change due to pore-pressure changes
- Fully-coupled stress-pore pressure analyses
- User Add-In constitutive models
Some SIGMA/W features are described in more detail in this collection of videos and documents:
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SIGMA/W is formulated for 2-dimen-sional plane strain or axisymmetric problems using a small displacement, small strain, incremental load formulation. For each load step, incremental displacement at each node resulting from the incremental load is computed and added to the displacement at the beginning of the load step to give the total displacement. For soil models with nonlinear material properties, SIGMA/W solves the equations iteratively using the Newton-Raphson technique; soil properties are updated every iteration until a converged solution is achieved.
You can simulate the filling and excavation of materials by activating or deactivating finite elements at various stages of the construction process. SIGMA/W can be used with SEEP/W for un-coupled consolidation analyses.
SEEP/W calculates transient pore-water pressure changes due to the applied load, while SIGMA/W calculates deformations resulting from the pore-water pressure changes.
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When you purchase a SIGMA/W 2007 license you also receive a copy of the SIGMA/W Engineering Methodology book,
Stress-Deformation Modeling with SIGMA/W 2007. This book is not a software manual but a full-length book
that discusses why and how to model. It does not describe how to use the commands in the software
or which buttons to click - that is provided in detail in the Online Help. Instead it is about
thinking: how to think before, during and after setting up and solving a model. The Engineering
Methodology book has chapters devoted to:
- Introduction
- Numerical Modeling: What, Why and How
- SIGMA/W: Fundamentals and Practical Modeling Considerations
- Meshing
- Material Properties
- Boundary Conditions
- Analysis Types
- Structural Elements
- Fill and Excavation
- Consolidation
- Numerical Issues
- Visualization of Results
- Illustrative Examples
- Product Integration
- Theory
- Appendices
- References
- Index
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The GeoStudio Student Edition is a free product designed as an aid to learning
geotechnical numerical modeling. It is an ideal teaching tool for university professors both at the
undergraduate and graduate levels. The software contains
limited versions of SLOPE/W, SEEP/W, SIGMA/W, QUAKE/W, TEMP/W, CTRAN/W, AIR/W and VADOSE/W.
More information about GeoStudio 2007 Student Edition...
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The GeoStudio Basic Edition is a feature-limited version of seven products: SLOPE/W, SEEP/W, SIGMA/W, QUAKE/W, TEMP/W, CTRAN/W and AIR/W.
The Basic Edition is ideal for use in routine engineering practice for the analysis
of problems with limited geometric complexity. While primarily intended for analyzing
the stability of natural and man-made earth slopes, you can also use GeoStudio Basic
for the analysis of confined and unconfined steady-state seepage problems, for the
analysis of linear-elastic settlement and stress distribution problems, for the
tracking of contaminants within ground water flow and for the analysis of freeze-thaw
problems.
More information about GeoStudio Basic Edition...
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Pentium III with Microsoft Windows 2000, XP, or Vista
Intel dual-core processor with 1 GB of RAM recommended
800x600 display (1024x768 or higher is recommended)
Microsoft Internet Explorer 6 or higher
.NET 1.1 (.NET 2.0 included on the CD)
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SIGMA/W 2007 ships with these items:
- A CD-ROM containing GeoStudio 2007 and Seep3D
- A Resources CD-ROM containing tutorials and detailed example problems
- Free Student and Viewer licenses for all software on the CD (except for
Seep3D,
which does not have a Student license)
- Hardware keys for any licenses you purchased. The license files themselves will be delivered electronically.
- Engineering Methodology books for each product you purchased
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