Boundary Types

The first step in creating a model (after defining the Project Settings) is to draw the boundaries of the model.

The following is a brief summary of the boundary types defined in Slide.

External Boundary

Closed polyline, defining the extents of the soil region you wish to analyze.

Material Boundary

Arbitrary polylines, used to define zones of different material properties, within the External Boundary.

Water Table

An arbitrary polyline, used to define a Water Table (phreatic surface) for pore pressure calculations.

Piezometric Line

An arbitrary polyline, used to define a Piezometric Line for pore pressure calculations.

Tension Crack

An arbitrary polyline, used to define the lower limits of a Tension Crack zone.

Drawdown Line

An arbitrary polyline used to define the lower limit of the Water Table for a Rapid Drawdown analysis.

Soil Profile Boundaries

Soil Profile boundaries are only applicable if the Soil Profile option has been enabled in Project Settings. Soil Profile boundaries can represent material boundaries, the ground surface, or other model boundaries.

Weak Layer

A weak layer is an arbitrary polyline which is used to model a potential sliding interface such as a joint or any other type of discontinuity. A weak layer is assigned strength properties. Failure surfaces which coincide with a weak layer will use the strength parameters assigned to the weak layer.

See the Weak Layer Overview topic for details.

Anisotropic Surface

An anisotropic surface is used to define the direction of anisotropy for anisotropic material layers such as folded bedding. See the Anisotropic Surface Overview topic for details.