The goal of this research activity is the realistic modelling of the rock mass for rock engineering projects under consideration of rock mass quality and structure, primary stress situation and construction method. Realistic models are an important basis for the route selection, the determination of feasible construction methods, as well as for the estimation of support requirements and construction costs during design. During construction the models support the decisions on site with respect to required probe drillings, round lengths, support quantity and quality, and mode of construction. For a continuous update of the model, complete documentation and processing of all available data is required. An important aspect for the modelling is the knowledge of the primary stress situation. Besides thorough field work, tectonical considerations, and measurements, numerical 3-D modelling is used to determine the stress field. The evaluation of monitored data - in general displacement measurements - in combination with 2-D and 3-D numerical modelling will lead to an increased ability to predict rock mass behaviour. Improved tools for evaluation and interpretation of monitored data are developed in close co-operation with industry. Correlating the geological, geotechnical, and relevant data from construction, the parameters relevant for the rock mass behaviour can be identified. This approach, in the long run, shall replace the classical rock mass rating systems.