A numerical model for the tunnel boring machine interaction with soil
Mechanized shield tunnelling is a reliable way of constructing tunnels in soft soil, particularly in urban areas. However, a lack of understanding of the physical interaction between the TBM-shield, the soil, and the process fluids contributes to the long learning curves often experienced and hinders improvement of the machine’s driving rationality. A numerical shield-soil interaction model is proposed that bases the extent and spatial distribution of the displacements induced by the advancing shield on TBM monitoring data. The model includes the unloading-reloading condition of the surrounding soil and the possible infiltration of process fluids around the shield periphery. This infiltration influences the equilibrium of the TBM. A set of novel soil reaction curves is also introduced specifically to model a TBM interaction with the surrounding soil. The study offers an innovative outlook on the tunnelling related soil displacements. Results indicate that a more rational approach to mechanized shield tunnelling in soft soil is possible.
3D Modelling of an EPB Tunnel Drive in Mixed Geological Formation
Se simulara, mediante un modelo numerico 3D de elementos finitos, el proceso de excavacion y construccion del tunel de la Linea 9 del Metro de Barcelona en el entorno de la zona Franca. Se validara el modelo, reproduciendo los movimientos del terreno, en superficie y en profundidad. Se estudiara la interaccion del proceso de excavacion con edificios cercanos.
Process‐oriented numerical simulation of shield‐supported tunnelling in soft soils /
A numerical simulation model for the analysis of shield‐supported tunnelling processes based on the finite element method is presented. The process‐oriented computational representation of the tunnel drive enables forecasts of the effects of different tunnelling process parameters, like support and grouting pressures or the advance rate, on ground deformations and stresses, groundwater conditions or the loading of the shield machine and segment lining. This requires, in addition to the realistic numerical modelling of the sequential tunnelling process, the supporting measures and the surrounding ground, to employ adequate numerical models to describe the intricate interactions between the ground and the tunnelling process resulting from the face support, the contact between shield skin and ground, the shield tail grouting, the steering of the machine and the lining. These process‐oriented interactions determine the structural behaviour above and behind the machine to a considerable degree. Selected numerical applications demonstrate the capabilities of the simulation model described here for the analysis of interaction mechanisms in mechanical tunnelling.