The two-component backfilling system is the most frequently used method to fill the annular gap created during the shield machine advancement. This gap, due to the head overcut, the shield thickness and conicity and the tail brushes size should be filled continuously in order to avoid mainly surface displacement and linings movements. Nowadays this technology is the most chosen due to operative (both...

In shielded mechanized tunnelling, the annular void created during the advancement of a Tunnel Boring Machine (TBM) must be continuously filled to minimize surface settlements and ensure optimal contact between the segment lining and the surrounding soil. Two component grout is widely used in the backfilling process due to its ability to meet both operational and performance requirements. This grout system...

Bentonite slurries are essential for the operation of Slurry Tunnel Boring Machines (TBMs), helping to stabilize the excavation face, prevent soil collapse, and control groundwater inflow. This study examines the performance of a sodium-activated bentonite slurry used in tunnelling, focusing on its physical-chemical properties, rheological behavior, and interaction with soil. Tests were conducted to measure...