Surface Options

The Surface Options dialog in the toolbar or the Surfaces menu allows you to select:

NOTE: Surface Options is also available in the default right-click menu.

Surface Type

The Surface Type determines what type of slip surface you 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.

Circular Surfaces

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 you 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

image\composite1.gif

Non-Circular Surfaces

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.

TIP: see the Slide Search Methods article for an overview of the different search methods in Slide and suggestions for using them effectively

Circular Surface Search Methods

If the Surface Type = Circular, THREE different Search Methods are available:

Grid Search

Slope Search

Auto Refine Search

Non-Circular Surface Search Methods

If the Surface Type = Non-Circular, FIVE different Search Methods are available:

Block Search

Path Search

Simulated Annealing

Auto Refine Search

Cuckoo Search

Surface Filter

In the Surface Options dialog, the Surface Filter options allow you to apply additional filters or constraints to the allowable slip surfaces generated by any search method (circular or non-circular). The following options are available.

Minimum Elevation

The Minimum Elevation is the minimum allowable Y-coordinate for any slip surface. NOTE:

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:

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 Area

The Minimum Area option allows you to filter out slip surfaces which create a sliding mass with less than a user-defined minimum total cross-sectional area.

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 slice weight.