C/Phi Function

A C/Phi Strength Function allows you to define Mohr-Coulomb Cohesion and Friction Angle as a function of Normal Stress, by entering data in the format Effective Normal Stress / Friction Angle / Cohesion.

To define a C/Phi Strength Function:

1. Set the Strength Type = C/Phi Function in the Define Material Properties dialog.
2. Select the New button.
3. You will see the Define C/Phi Strength Function dialog.
4. Enter a Function Name.
5. Enter the Effective Normal stress, Cohesion and Friction Angle data which defines your C/Phi Function. As the data is entered, it will appear in the graph area at the right of the dialog.
• You can use the buttons at the top of the data entry grid to help carry out the editing of the data (i.e. insert row, remove row, copy, paste etc)
• The interpolation is done on the cohesion and friction angle level, meaning for a given value of effective normal stress the cohesion and friction angle are interpolated per your input.
6. When all data points have 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 C/Phi Function list. By selecting a Function Name from this list, you can now apply a C/Phi Function to any material in the model.

Import/Export C/Phi Strength Functions

C/Phi 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 C/Phi Functions each time they are required in a model.

To Export (save) a C/Phi Function:

1. Select the Export button in the Define C/Phi 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 a C/Phi Function:

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