Probabilistic Analysis Overview

In a RocTopple Probabilistic analysis, you can define statistical distributions for input parameters (e.g., orientations, shear strength, water level) to account for uncertainty in the values of input parameters. The analysis is a Factor of Safety distribution from which a Probability of Failure is calculated.

The general procedure for carrying out a probabilistic Analysis with RocTopple is as follows:

1. Select Analysis Type

In the Project Settings dialog, set Analysis Type = Probabilistic (see Analysis Type Setting in RocTopple).

2. Set Sampling Options

In the Project Settings dialog, choose the Sampling Method and enter Number of Samples (see Sampling Method Setting in RocTopple).

3. Define Random Variables

To carry out a Probabilistic analysis, you must define one or more input parameters (e.g., joint orientation, shear strength) as random variables by assigning statistical distributions to the desired variables and entering the required statistical parameters (e.g., mean, standard deviation). See Random Variables in a RocTopple Probabilistic Analysis for a summary of the random variables that can be defined in RocTopple.

NOTE: Any input parameter that is NOT assigned a statistical distribution is assumed to be exactly known (by the Mean value) and will not be involved in the statistical sampling process.

4. Compute

To compute a Probabilistic analysis, select Compute on the toolbar or the Analysis menu. If the Autocompute option is enabled, the Probabilist analysis is automatically computed when you click OK or Apply in the Input Data dialog.

5. View Analysis Results

After the analysis is computed, the 2D View displays the Probability of Failure and detailed results are reported in the Info Viewer. Probabilistic input and output data can be plotted on histogram plots and scatter plots. Can also be exported for further analysis and processing.