Occurence:

SLOPE/W may generate optimization results that are physically inadmissible.

 

Resolution:

In SLOPE/W, optimization is used to seek a lower factor of safety value by incrementally altering portions of the previously solved critical slip surface. This random walk procedure may produce a shape that is physically inadmissible, so optimization must be used carefully and methodically to enhance an acceptable critical slip surface. Dramatic changes in the optimized factor of safety (i.e. greater than 20%) or the generation of a highly concave slip surface often indicates an unrealistic result.