Upgrading railway embankments in Denmark is connected with high costs, using the partial factors for geotechnical design calibrated for general application. Reliability-based calibration of the partial factors to a reasonable safety level, taking into account the specific design situations and uncertainties relevant for railway embankments, is one way to reduce the costs. At “Nordvestbanen” in Northwestern Zealand, a reliability-based calibration of the partial factor has been performed, resulting in an optimal partial factor for the considered subsoil, cf. (Lodahl et. al. 2012).

In the present paper, two design cases where the updated partial factor was applied are examined. The evaluation of the actual design cases focuses especially on the validity of the chosen slip surface in the calibration. Examples of acceptable and unacceptable slip surfaces are presented and discussed.