Swedge > Probabilistic Analysis > Persistence Analysis
Joint Persistence Analysis is a feature of the Swedge Probabilistic Analysis, which allows you to define statistical distributions for joint persistence. For a given wedge size, randomly generated values of persistence are used as a filter to determine if a wedge can actually form.
If the wedge dimensions exceed the allowable persistence, then the wedge cannot exist.
If the wedge dimensions are smaller than the allowable persistence, then the wedge can form and a safety factor is calculated.
This process is repeated for the specified number of random trial samples.
The persistence analysis can be applied to the maximum wedge size, or to a randomly generated wedge size. The random variation of wedge size simulates the random variation of the wedge location (i.e. the intersection of two joint planes may daylight anywhere on a slope face).
Input dialog for Persistence analysis
The Persistence analysis option is a refinement to the Swedge Probabilistic analysis. It can be used on its own, or simultaneously with any other Probabilistic analysis options in Swedge (i.e. you can define any other input random variables, in addition to the joint persistence).
In general, by checking for allowable joint persistence in a probabilistic analysis, this can only DECREASE the calculated probability of failure. The Persistence analysis option should give more realistic estimates of probability of failure for slopes where the joint planes are not continuous.
NOTE: the Persistence Analysis option cannot be used in conjunction with the Scale Wedge option. If the Persistence Analysis option is in use, then the Scale Wedge option will NOT be available, and vice-versa.