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SIGMA/W 2012 stress-deformation analysis.



SIGMA/W is formulated for 2-dimensional 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 regions at various stages of the construction process. SIGMA/W can be used with SEEP/W for uncoupled consolidation analyses. SEEP/Wcalculates transient pore-water pressure changes due to the applied load, while SIGMA/W calculates deformations resulting from the pore-water pressure changes.




  • 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, 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.

  • Uncoupled volume change due to pore-pressure changes.

  • Fully-coupled stress-pore pressure analyses.

  • User-defined Add-In constitutive models.


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