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Importing Slide Files / SSR Analysis

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Importing Slide Files / SSR Analysis
Slide is a 2D limit equilibrium slope stability program produced by Rocscience. Phase2 version 6 can import files written by version 5 of Slide. This allows you to perform a finite element stress analysis and slope stability analysis on a Slide model, using Phase2. This tutorial will provide an overview of Slidefile import and the Shear Strength Reduction method in Phase2, and then demonstrate the procedure with an example. Topics Covered • • • • Importing a Slide file Slide options which are supported in Phase2 Slide options which are not supported in Phase2 Shear Strength Reduction (SSR) analysis

Importing a Slide Data File
To import a Slide data file (.sli file), there are two possible methods: 1.You can use the File > Import > Import Slide File option. 2. Or you can use the File > Open option and set the Files of Type to Slide File Format (*.sli), as shown below.

Both methods provide identical functionality for importing Slide data files into Phase2.

Phase2 v.6.0

Tutorial Manual

Importing Slide Files / SSR Analysis

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After selecting the Slide data file that you wishto import, you will see a dialog with options pertaining to how you wish to import the file.

In general, you will simply press OK, but there might be instances where you wish to modify boundaries, customize the mesh, or not start by running a Shear Strength Reduction (SSR) analysis to determine the factor of safety of your slope. In which case, you can use this dialog to customize how the Slidefile is imported. After the import, you might see a warning dialog such as:

Not all functionality in Slide is supported by Phase2. Certain material and support models are not supported (see below). If a Slide model contains unsupported functionality, a warning dialog is issued. In this case, the user must change the material or support models to one supported by Phase2. The method for definingmaterial and support models is very similar between Slide and Phase2, so the user should have no problem changing the model.

Phase2 v.6.0

Tutorial Manual

Importing Slide Files / SSR Analysis

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Shear Strength Reduction Method
The Shear Strength Reduction (SSR) method is widely used to determine the factor of safety of a slope using the finite-element method and is used in Phase2version 6. The method simply reduces the shear strength of the material until the model becomes unstable. The point of instability is taken as the factor of safety of the slope. It is not the purpose of this document to describe the method. However, to understand the applicability of the method, it is important to understand its advantages and disadvantages. Some of the advantages of the SSRmethod include: 1) you do not have to define a failure surface or search for a minimum failure surface, how the slope fails is a result of the SSR method 2) equations of equilibrium are all satisfied, 3) strains and displacements in the soil and/or rock can be calculated, 4) strains, displacements, axial force and moment distributions in support can be calculated 5) progressive failure can be modeled.The disadvantages include: 1) Not as widely known or trusted as the limit-equilibrium methods, 2) requires more data such as material modulus, stiffness, plasticity parameters, in-situ stress, boundary conditions etc. 3) Mesh generation and model setup can be difficult and may require a high level of modeling expertise, 4) Limit equilibrium has more material models and is numerically simpler, 5)Finite-element is prone to convergence, tolerance, and numerical instability issues, 6) It is much slower and compute time intensive. Phase2 version 6 tries to remove a lot of the complexity of defining a finite-element model by directly importing a Slide data file, automatically meshing the model, automatically defining in-situ stress states, boundary conditions and material models. Thus...