Visualization analysis of tunnel face stability during shield tunnelling in soft grounds

The aim of this paper is to determine the face stability of a circular tunnel driven by a pressurized shield. The analysis is performed by a novel visual platform named as TBM Studio, which is developed to perform automatic analytical and visualization analysis on the tunnel face stability during shield tunnelling in soft grounds. Data modeling, analysis, and visualization are programmed separately in different C# projects which are integrated together. The hydrogeological profile of the analysis domain can be automatically generated, and the analysis cross sections can be automatically identified. Several user-friendly interfaces are created to facilitate data input, model calculation, and result visualization. The platform provides users with different analytical and empirical methods to calculate face support pressure and associated ground settlement. The data structure and database are established based on object-oriented programming method. Data-driven dynamic modeling schemes are developed for 3D visualization of the ground and the tunnel, which is efficient and flexible. The application example indicates that visualization analysis by TBM Studio is useful for practicing engineers to select the most appropriate face support pressure calculation model, to determine the safe range of face support pressure, and to identify the critical sections for shield tunnelling prior to excavation.