The Joint Combination Analyzer is a very useful tool in Unwedge, which allows you to automatically carry out the Unwedge analysis on multiple combinations of 3 joints, if your input data includes more than 3 possible joint planes.
A summary of all analyses can then be viewed, which allows you to quickly determine which combination of 3 joints is the most critical (i.e. you can sort results according to maximum support pressure, safety factor, wedge weight etc).
Based on the results of the Combination Analyzer, you can then select the most critical combination of joints, and perform a more detailed analysis on that particular combination.
NOTE: it must be emphasized that Unwedge can only analyze 3 joint planes at one time. The Joint Combination Analyzer automatically carries out the Unwedge analysis on each possible combination of 3 joints. Each analysis is carried out separately, using a different combination of 3 joints. Unwedge does NOT consider more than 3 joint planes simultaneously in the analysis.
To use the Joint Combination Analyzer:
Select the Joint Orientations tab in the Input Data dialog.
The Joint Combination Analyzer is only available if more than 3 joints have been defined in the Input Data dialog. See the Multiple Joint Combinations topic for more information about adding additional joints, and Joint Combinations.
When more than 3 joints are defined, the Combination Analyzer option will be enabled. Select this button to view the Combination Analyzer dialog.
Note: the Combination Analyzer option is also available directly from the Analysis menu, when more than 3 joints are defined. You do not have to go through the Input Data dialog.
Select the Compute Combinations button in the dialog, and Unwedge will automatically perform the analysis on each combination of 3 joints. Results will immediately appear in the dialog.
Using the drop-lists in the dialog, you can now sort the analysis results according to various criteria, such as Required Support Pressure, Factor of Safety, Wedge Volume and other parameters.
The first drop-list performs the primary sorting of the data.
The second drop-list performs a secondary sorting using a different criteria.
For example: if you were sorting first by Factor of Safety, you might have several Roof Wedges with a zero safety factor, listed first. The secondary sort will sort identical results from the first list (e.g. FOS = 0) according to another criteria (e.g. sort by Wedge Weight).
The Joint Combinations corresponding to the data are listed at the right (e.g. Joint 1,3,5). If you click on any row of the data, the corresponding joint combination will be highlighted on the stereonet at the right of the dialog.
You can also choose to filter the results by wedge type, using the Wedge Selection drop-list. You can choose Perimeter Wedges, End Wedges, All Wedges, or any individual wedge (e.g. Roof Wedge).
Use the list boxes to sort and filter the results of the Combination Analyzer. After studying the results, this will allow you to determine which joint combination (or combinations) are the most critical to the excavation analysis.
To automatically load a joint combination from the Combination Analyzer dialog into the Input Data dialog:
Click on the corresponding Joint Combination in the results listing.
Make sure the "Use selected combination when dialog is closed" checkbox at the bottom of the dialog is selected.
When you select OK in the Combination Analyzer dialog, the selected Joint Combination will be automatically loaded in the Input Data dialog, so that you can perform further analysis and support design, using the most critical Joint Combination.
Finally, note that the results of the Combination Analyzer are not saved after the dialog is closed. If you wish to repeat the Combination analysis, you can repeat the above steps at any time, and re-compute the results in the Combination Analyzer dialog.