TBM- ground interaction modeling

Extensive underground tunneling is being carried out today all over India using Tunnel Boring Machine (TBM) due to the significantly reduced construction time. However, field monitoring studies report ground movements and damages to buildings under which the TBM advanced through. This necessitates critical research on TBM- ground interaction to predict variations in the in-situ ground condition, optimize the TBM performance and avoid any damage to the adjacent structures. The present study focuses on a closed- face pressurized tunneling concept where all the relevant components of a mechanized tunneling process like application of face pressure, cutter head torque, tail grout pressure, back- up trailer weight and shield- skin friction, soil removal, shiel d removal, lining installation and grout hardening are numerically modelled, for a shallow tunnel of 8.0 m diameter. Tunneling is carried out in stiff clay at a depth of 19.0 m from the ground surface. Ground response in terms of deformation and pore pressure is monitored at critical locations for each excavation. As the tunneling progressed, changes in these parameters could be very well established in the numerical analysis.