GGU-STABILITY: Step 10: Generate slip surfaces (Ex. 1)

After answering the "Generate new slip surfaces?" query with "Yes" a dialog box opens, which can also be reached via the "Nail wall/Generate slip surfaces" menu item. Slip surfaces with 2 polygonal sections are generated (two-wedge failure mechanism).

In the upper group box of the dialog box, define the inclinations of the rear slip line, responsible for the active earth pressure acting on the system. The two inclinations given are used as limit values. The number of subdivisions used is given by "No. of subdivisions".

Define the location of the front slip line in the lower group box. The lowest slip lines always begin at the base of the wall and end at the tips of the nails. If the "Only of lowest nail" check box is deactivated, additional slip lines are also generated from the soil nails above. These lines will begin at the head of the respective nails or at a given distance below this; you can specify this distance with "Starting point under nail head [m]". The slip lines end at the nail foot if the slip line has a positive inclination; otherwise, the slip line is rejected (except for the lowest nail). If the "No. of intersections with nail" value is > 0, additional slip surfaces are generated, which intersect the respective nail.

The number of newly generated slip surfaces is shown in a message box. After closing the message box, the slip surfaces are immediately shown on the screen.