Initial stresses, the stresses during filling and before discharging, measured in an experimental silo have been compared to stresses calculated with slice element methods (Walters, Motzkus). With the approach of Motzkus, initial stresses can be predicted fairly good, whereas Walters’ approach yields an overestimation of the vertical stresses acting on the feeder. Since the experimental results showed that the compressibility and the deformation of the bulk solid have to be taken into account, a new slice element method is worked out. The new method is based on slices of variable geometry, thus considering the effect of the deformation of the bulk solid.