In *Settle3D*, the change in total stress caused by external loads such as embankments or fills can be calculated by five different methods:

- Boussinesq
- Westergaard
- Multiple Layer
- Vertical Ratio (2:1)
- Vertical Ratio (angle)

Details on these methods can be found in section 2.3 of the *Settle3D *Theory Manual, and in the Stress Computation section of the Online Help.