# Anisotropic Strength Function

The Anisotropic Function model allows you to define discrete angular ranges of slice base inclination, each with its own cohesion and friction angle.

To define an Anisotropic Strength Function:

1. Set the Strength Type = Anisotropic Function in the Define Material Properties dialog.
2. Select the New button.
3. You will see the Define Anisotropic Strength Function dialog.
4. Enter a Function Name.
5. Enter values of Angle To, c and phi, defining the strength properties within each angular range.
• The FIRST angular range always starts at –90 degrees (this is the default value of the FIRST Angle From value, and cannot be edited by the user).
• The angular ranges must be ordered, counter-clockwise, from –90 to +90.
• The Angle From values cannot be edited by the user, and are automatically defined by the Angle To value in the previous row.
• The LAST angular range always ends at +90 degrees (this must be entered by the user, as the LAST Angle To value, or you will get an error message when you select OK).
• As the data is entered, the chart at the right of the dialog will be updated to display the Anisotropic Function you are defining.
• Check the chart carefully, to make sure that you have defined the intended function (i.e. all angular ranges are correct, and c and phi values are correct).
• You can use the buttons at the top of the data entry grid to help carry out editing of the data (i.e. insert row, remove row, copy, paste, etc.)
6. When all data has been entered, select OK, and you will be returned to the Define Material Properties dialog. The Name of the function you have just defined will appear in the Anisotropic Function list. By selecting a Function Name from this list, you can now apply a Strength Function to any material in the model.

Example

A simple function consisting of three ranges is illustrated below.

The data in this example defines three angular ranges of strength properties:

• – 90 to –30 degrees , with c = 10 and phi = 35
• – 30 to 0 degrees , with c = 1 and phi = 20
• 0 to 90 degrees , with c = 5 and phi = 10

## Import/Export Anisotropic Strength Functions

Anisotropic Functions can be Exported (saved) in a separate functions file, and Imported into other Slide2 files, so that you do not have to re-define Anisotropic Functions each time they are required in a model.

Anisotropic Function files in Slide2 use a *.FN3 filename extension.

To Export (save) an Anisotropic Function:

1. Select the Export button in the Define Anisotropic Strength Function dialog.
2. In the Save As dialog, enter a filename, and save the file. Note: the default filename will use the Function Name, but this can be changed if required.

To Import an Anisotropic Function:

1. Select the Import button in the Define Anisotropic Strength Function dialog.
2. In the Open File dialog, open the Anisotropic Function file that you wish to import, and it will be imported into the Define Anisotropic Strength Function dialog. Select OK to add this function to the list of currently defined Anisotropic Functions in the current model.