How can I scale wedge size in Swedge?

By default Swedge shows the maximum size wedge which would exist if the joint planes are of infinite extent and the upper slope and slope length (along the strike of the slope) are of infinite extent.  In order to limit the size of the wedge, Swedge offers a number of solutions.

The first options that should be investigated are the Slope Length and Bench Width options, which allow you to limit the size of the slope along the upper face and along the strike of the slope.


Deterministic Input Data dialog


The second option for limiting the size of the wedge is the Scale Wedge option in the Analysis menu.  It allows you to define persistence and trace length for the individual joints.  If you have some field measurements on the extents of the joints in your model, you can use these inputs to limit the size.  Tutorial 5 has a good description of how to use these techniques to reduce the size of a wedge to a more realistic size.


Scale Wedge option allows persistence and trace length to be defined


Finally, there are the tension crack and slope height options.  These can also be used to limit the size of the wedge, but use these options carefully.  Use a tension crack if field mapping indicates that one exists, and a tension crack shouldn’t be added if it does not exist in the field.  Slope height can be used if field measurements indicate a certain vertical height of the wedge.  The slope height basically limits the vertical height of the wedge, and so it can be used to reduce the size of the wedge.  However, the trace length option in the Scale Wedge dialog may be a preferred way to limit wedge size.


Finally, remember that all methods of reducing wedge size should be applied based on proper field measurements or actual slope geometry.  In the end, it is up to you to choose the appropriate method.