Slip Surface Filter Options
The Filters 
option in the Slip Surface Options dialog allows you to apply additional filters or constraints to the allowable slip surfaces generated by any Search Method. For example, very shallow or very small slip surfaces can be discarded from the analysis using the filter options.
The following Slip Surface Filter options are available.
Minimum Elevation
The Minimum Elevation is the minimum allowable Z-coordinate for any slip surface.
- By default, Slide3 uses the lower limits of the External Boundary, as a limiting boundary which a slip surface cannot cross. It is NOT necessary for the user to specify a Minimum Elevation unless you want to use a specific Z-coordinate ABOVE the lower limits of the External Boundary.
- To define a Minimum Elevation, select the Minimum Elevation checkbox and enter a Minimum Elevation in the edit box. In this case, any slip surfaces generated which go below the Minimum Elevation will be discarded.
Minimum Depth
The Minimum Depth option can be used to filter out shallow slip surfaces, which may be generated by a search. The Minimum Depth option works as follows:
- When a slip surface is generated, the columns are generated for the surface, and the MAXIMUM column height is determined. The column height is measured VERTICALLY, from the slip surface to the ground surface.
- If the Minimum Depth option is enabled, then the MAXIMUM column height for a slip surface must be GREATER than the Minimum Depth value. If not, then the slip surface will not be analyzed.
If you do not wish to analyze shallow slip surfaces which may be generated by a search, then use the Minimum Depth option to filter out these surfaces from the analysis.
Minimum Volume
The Minimum Volume option allows you to filter out slip surfaces which create a sliding mass with less than a user-defined minimum total volume.
Minimum Weight
The Minimum Weight option allows you to filter out slip surfaces which create a sliding mass with less than a user-defined minimum total weight.