Shear Strength Reduction

The Shear Strength Reduction option of the Project Settings dialog in RS3 allows you to automatically perform a finite element slope stability analysis using the Shear Strength Reduction (SSR) method.

To enable the Shear Strength Reduction method:

1. Select the Determine Strength Reduction Factor checkbox on the Shear Strength Reduction page of the Project Settings dialog.
2. You may customize the analysis parameters described below, or the use default values.

Initial Estimate of SRF

The initial estimate of the Strength Reduction Factor (SRF) for the first iteration of the SSR analysis. By default, this is set to 1.

Automatic Step Size

The Step Size is the difference in the Strength Reduction Factor between two iterations of the SSR analysis.

If Step Size = Automatic (this is the default selection), an appropriate Step Size is automatically determined by RS3, and may vary from iteration to iteration (i.e. it may increase or decrease between any two iterations).

TOLERANCE (SRF)

If Step Size = Automatic, the Tolerance (SRF) determines the convergence (end of analysis) for the SSR method. The Tolerance (SRF) is implemented as follows:

1. When the difference in SRF between two iterations of the SSR method is less than the Tolerance (SRF), and...
2. The Stress Analysis has converged for the SSR iteration with the lower SRF, by does not converge for the SSR iteration with the higher SRF, then...
3. The SSR analysis is deemed to have converged. The critical value of SRF is the SSR iteration with the lower SRF.

Custom Step Size

If Step Size = Custom, this allows the user to define the Step Size and Final SRF