Slip Surface Overview
Slip surfaces are the 3-dimensional failure surfaces for which the safety factor is calculated during a Slide3 slope stability analysis. Automated search methods can be used to search for the critical slip surfaces, or user-defined surfaces can be defined.
To define slip surfaces and search options select the Slip Surfaces 
workflow tab and select an option from the toolbar or the Surfaces menu. The following options are available.
Slip Surface Options
The Slip Surface Options dialog is the main dialog for defining the slip surface type, shape, generation method and search method.
Define Search Grid
The Define Search Grid option allows you to define a search grid if the Search Method = Grid Search.
User-Defined Surface
The User Defined Surface options allow you to add individual user-defined slip surfaces to the model.
Search Limits
The search limits options allow you to define inclusion or exclusion zones on the model to narrow the search area.