Prediction of performance and cutter wear in rock TBM: Application to Koralm tunnel project

Excavation by Tunnel Boring Machines is the tunnelling method most frequently used nowadays in long infrastructural projects, in a wide range of geological conditions. In the last 40 years, many prediction models were developed to estimate TBM performance and cutter wear, using as input geological parameters. The research gives an overview of the existing penetration models for hard rock TBMs, identifies the most frequently used input parameters and summarizes the characteristics of the datasets on which the models are based on. Theoretical background is tested through the example of Koralm tunnel project, a 32.9-km-long base tunnel in Austria, in a 1000-m-long portion of the South tube in the construction lot KAT 2. The outcomes shows that the estimation of the penetration is reasonably accurate when applying models that are based on a database consistent with the project data, especially in terms of geology and typology of machine used in the excavation. The article proposes a design method for a system of TBM data analysis and prediction at the construction stage, based on a back-analysis process about machine data in different geological conditions. The methodology can be applied in any other project and the system is particularly useful in long tunnels, in which a continuous improvement of the ability of prediction can have an effective impact on time and costs