Slope Length
The Slope Length is an input parameter which can be used to limit or scale the wedge size. It can also be used as a display option.
The Slope Length can be customized if the Use Default Length checkbox is not selected. If Use Default Length is selected, then RocSlope2 assumes that the length of the slope is sufficient to accommodate the maximum wedge size computed for the slope.
For example, in the model below, a Slope Length of 50 meters has been specified and the wedge has been scaled accordingly. The Slope Length limits the maximum extent of the wedge, as measured along the crest of the slope.
- Slope Length is always measured along the crest of the slope (the line of intersection of the two slope planes). This is true even if the Slope and Upper Face have different Dip and Dip Directions.
- Remember that the Slope Length is a limiting value. If the current wedge size is already smaller than the specified Slope Length, then the wedge size will not be affected.
- If the Slope Length is not specified, it is possible to generate wedges which have a very "long" dimension along the length of the slope (for example, if one of the joint planes has a strike which is nearly parallel to the strike of the slope planes). This can result in wedges which have unrealistic dimensions. In this case, it may be necessary to use the Slope Length option to limit the wedge size.
Slope Length in a Probabilistic Analysis
A user-defined Slope Length is recommended in a Probabilistic Analysis, to ensure that all wedges generated by the statistical sampling of joint orientations will be limited in size by the Slope Length. If a Slope Length is not defined, then the Probabilistic Analysis may generate unrealistically long wedges, which may influence the analysis results.
Slope Length as a Display Option
When you specify a Slope Length, the model is drawn using the specified Slope Length. Therefore, even if you are not using the Slope Length to scale the wedge size, you can use the Slope Length to display the actual slope length or to adjust the appearance of the model for screen capture purposes. For example, in the model below, a Slope Length of 100 meters has been specified for display purposes; the wedge size is not affected.
If Use Default Slope Length is selected, then the graphical (apparent) slope length is automatically calculated based on the current wedge size.