Slide Model > Slip Surfaces
The Surface Options dialog in the Surfaces menu, allows the user to select:
the type of slip surfaces they would like to define and analyze (Circular or Non-Circular)
the Search Method and search parameters, if they are performing a critical surface search to find slip surfaces with the lowest factors of safety
Surface Type
The Surface Type determines what type of slip surface the user can define and analyze - Circular or Non-Circular.
The options available in the Surfaces menu depend on the Surface Type selected in the Surface Options dialog:
If the Surface Type = Circular, then the Surfaces menu allows you to define circular slip surfaces, as described in the Overview of Circular Slip Surfaces topic.
NOTE: if the Surface Type = Circular, AND the Composite Surfaces checkbox is selected in the Surface Options dialog, then composite circular / non-circular slip surfaces can be analyzed. This allows the user to analyze circular slip surfaces which intersect a bedrock surface, for example, as illustrated below. See the Composite Surfaces Tutorial on the Slide Tutorials page, for a tutorial which demonstrates the modeling and analysis of composite surfaces.
Example of Composite slip surface
If the Surface Type = Non-Circular, then the Surfaces menu allows you to define non-circular slip surfaces, as described in the Overview of Non-Circular Slip Surfaces topic. A non-circular slip surface is made up of piece-wise linear segments.
For a given SLIDE analysis, only one Surface Type can be selected, you cannot analyze both Circular and Non-Circular slip surfaces in the same analysis.
Search Method
In most cases, a SLIDE analysis will involve a critical surface search, in order to attempt to find a slip surface with an overall minimum factor of safety.
If the Surface Type = Circular, then THREE different Search Methods are available. See the Grid Search, Slope Search, and Auto Refine Search topics for details.
If the Surface Type = Non-Circular, then TWO different Search Methods are available. See the Block Search and Path Search topics for details.
NOTE: Surface Options is also available in the default right-click menu.