How do I check my factors of safety?

The "Reporting on Design" function lists any potential design problems identified by the software. Items considered are bending moment (compared with allowed sheet moment), toe smaller than recommended, danger of rotation in "no toe" designs and water levels. A check is also made on soil densities, and a warning is displayed if a submerged density seems large compared with the bulk density.

Other checks will be added as they are identified.

Note that Rules of thumb can be switched on/off in the Wall page of the define box. These can improve design safety.

I started working with SPW 911 and found that the passive earth pressure coefficient was not reduced by the reduction factor (R) as it is required by AASHTO Tables 5.5.2.C and 5.5.2.D.  Why not?

With cantilever walls, safety factors can be dealt with in several ways.  One of these is to divide the passive earth pressure coefficients by a reduction factors (typically 1.5 to 2.0.)  The other way is to compute the equilibrium condition for summation of forces and then add toe length.  SPW 911 uses the latter approach.  If you want to reduce the passive earth pressure coefficient, you can do so directly in the soils page.

Can the factor of safety (FOS) be set or changed? How is this done?

User can select Free Earth Support (FOS = 2) or Fixed Earth Support (FOS not applicable). User can enter a toe (including 0) manually. In all cases, FOS  can be calculated and displayed.

I am designing a cantilever wall, and would like a factor of safety of 1.4.  Program determines the penetration based soil layers and rule of thumb.  I've tried adjusting Kpc value of embedments layer.  This increases the penetration but does not increase the factor of safety, and has a bad effect on the deflection at the pile top.  What's the best way to deal with this?

Open the "Wall" page, switch "Automatic" off, and enter the toe manually.