GGU-STABILITY: "Generate slip surfaces" menu item

Using this menu item, you can create a variety of slip surfaces with just a few entries. Slip surfaces with 2 polygonal sections are generated (two-wedge failure mechanism).

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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.

Strictly speaking, an analysis utilising the "General wedge method" must also vary the intermediate slip line. The inclination of the intermediate slip line is adopted by the program at the same value as the rear principal slip line but with the opposite sign. Generally, this is not the most unfavourable location for the intermediate slip line only for highly variable stratification in the region of the intermediate and principal slip lines.