Uncertainty modeling and simulation of tool wear in mechanized tunneling

The planning of mechanized tunneling projects requires the consideration of complex constraints and project objectives. Process simulation provides a tool to virtually evaluate different concepts in changing environmental conditions. The consideration of uncertain influences is an essential task within the development of a holistic simulation model. Some aspects (e.g. technical disturbances) can be considered by application of a probability function. However, geotechnical constraints feature a fuzzy nature not well suited for a probabilistic approach. The authors present an approach based on Fuzzy Logic to integrate the performance related influence of wear of cutting tools on the advance rate. The approach is described in detail and demonstrated by an artificial example. Simulation experiments were performed to illustrate the influence of wear on the advance rate in the context of disturbances. This innovative approach to consider such an essential performance factor is another step towards a holistic simulation model of mechanized tunneling projects.