BIM is a process whose workflow differs significantly from conventional methods. An essential aspect of BIM is the creation of 3D models to which a wide range of information is assigned. This information model is placed at the center of a project as the single source of truth and is the basis for collaboration and communication. Since the information is directly assigned to the different parts of the model, data exchange is facilitated and the structured collection of data is promoted. However, the application of BIM for infrastructure projects is associated with several other challenges, such as integrating geology into the process. Geological data are often stored in GIS formats, whereby GIS are specialized in processing spatial data. Data exchange between GIS and BIM is difficult but necessary to better exploit the potential of BIM. Therefore, in this thesis current information flows of geological data into the BIM process are identified and analysed. Furthermore, in some cases voxel models are used to approximate geology. In this thesis, a voxel model was created with the aim of assigning the geology from a spatial input file to a 3D FE model. The results show that voxel models have a great potential to efficiently handle certain spatial queries.