ABSTRACT
Mechanised tunnelling is characterised by a staged process of excavation and lining erection and by a number of highly interacting components and processes (the soil including groundwater, the TBM, the linings, the support measures at the cutting face and the tail void) determining the soil response during tunnel advance. Reliable analysis of the construction process in mechanised tunnelling requires computational simulation models capable to realistically represent these components and their complex interactions in space and in time. Such models are relevant in the design stage, helping to find an optimal design solution for a tunnel project, as well as in the construction stage to support the steering of the Tunnel Boring Machine. Although numerical simulations are, by now, an integral part of tunnelling design, more or less significant simplifications are often made in the model-based representation of the excavation process. The simulation software ekate, developed as part of the design support system IOPT in the framework of TUNCONSTRUCT, incorporates realistic models for all relevant components involved in mechanised tunnelling (fully and partially saturated soft soils, the shield machine, the segmented lining, the face support and the tail void grouting) and follows closely the construction stages on site. Using modern programming concepts such as objectoriented modelling and parallelisation techniques allow for an efficient performance of 3D process oriented simulations of shield driven tunnelling. Particular attention is paid on the user-friendliness and robustness of the complete simulation work flow. For the continuous update of the model parameters according to monitoring data during construction, ekate is linked to the parameter identification software Inverse. This chapter addresses the role of numerical simulation software in the context of the design and the construction process in mechanised tunnelling and describes the software concept and its integration within the Integrated Design Support Soft ware IOPT. The relevant model components of ekate and Inverse including criteria for the selection of appropriate soil
models and results from selected validation examples and prototype applications to mechanised tunnel construction in soft ground conditions are presented.
