Janbu

In Germany, the annual economic damage attributable to mass movements is estimated at around €250 million. Studies indicate that there are relatively high losses, especially on traffic routes.
Preventive measures are necessary in order to prevent damage. This includes the installation of retaining structures in embankments to protect stability.
For the construction of stable slopes with adequate retaining structures, preliminary measurements must be made, which allow an assessment of the stability.
For this purpose, there are a variety of procedures that use different investigation methods. In this thesis, three analytical methods (Bishop, Janbu, General wedge method) and one numerical method (finite element method) were compared. The calculations were based on the example of the construction of a new cycle path in Bavaria.
The calculations were made using conservative and favourable soil parameters. Furthermore, soil parameters of the existing soil were determined by shear tests, which were included in additional calculations.
In the analytical methods, the decisive fracture area was either determined by varying the radius and the center coordinates or assumed to be in a certain area of the earth's body. 
The numerical approach of the finite element method, in contrast, made it possible on the one hand to calculate the failure mechanism and on the other hand to obtain information on displacements and deformations. For this purpose, however, further soil properties had to be determined or estimated and a correct material model had to be chosen to describe the plastic
behaviour of the soil.
The calculations showed that the geometry and the relative position of the different soil types within the earth mass are decisive for the shape of the sliding surfaces.
If a slope has simple geometries and the geological structure is uniform, numerical methods are sufficient to determine stability. If complex geometries are present and the plastic behaviour is to be tested, the application of numerical methods such as the finite element method is recommended. 
Moreover, concrete functional relationships between certain soil properties and stability were determined through several parameter studies.
An additional modelling of the project using photogrammetric methods enables further processing in the field of Building Information Modelling.