Reduction

*Reduction
<FoS_0>, <Delta FoS_0>, <Delta FoS_max>, <Delta FoS_min>

This procedure is used to perform a strength reduction analysis. In a reduction analysis, inertia effects are not taken into consideration. A reduction step can be linear or nonlinear, but time-dependent material effects (e.g. creep, swelling) are ignored. However, rate-dependent plasticity and hysteretic behavior are taken into account.

The following line specifies the - Initial factor of safety \(\text{FoS}_0\) - The initial increment of the factor of safety \(\Delta \text{FoS}_0\) - The maximum increment of the factor of safety \(\Delta \text{FoS}_\text{max}\) - The minimum increment of the factor of safety \(\Delta \text{FoS}_\text{min}\)

Recommended values are:

\(\text{FoS}_0\)	\(\Delta \text{FoS}_0\)	\(\Delta \text{FoS}_\text{max}\)	\(\Delta \text{FoS}_\text{min}\)
1.	0.01	0.05	0.0001

The recommended value for the maximum number of iterations maxiter is 100 for use with the Mohr-Coulomb-2 model.

Once the increment \(\Delta \text{FoS}\) falls below \(\Delta \text{FoS}_\text{min}\), the analysis is terminated. Details are provided in the Theory Manual.

Note that time intervals \(\Delta t\) are set to 1 and the total time is automatically set equal to the maximum number of increments specified in the step definition. This should be considered when using amplitude definitions such as loading or unloading ramps.