Technical FAQ

Cutter ring wear limits are strictly governed by geotechnical abrasion metrics. Typically, when radial wear exceeds 20mm, the tungsten carbide ring must be replaced. Operators perform hyperbaric interventions via pressurized air locks to manually change tools at the tunnel face under extreme hydrostatic loads.

Earth Pressure Balance (EPB) relies on the mechanical conditioning of the excavated soil using surfactant foams and polymers. This creates a semi-fluid plug in the screw conveyor, creating a pressure gradient that matches the in-situ ground pressure, preventing water ingress and face collapse.

Modern precast concrete segments are designed for a service life of 120 years. They utilize Steel Fiber Reinforced Concrete (SFRC) mixed with silica fume to drastically reduce permeability, combatting chloride-induced corrosion of structural rebar grids.

No. TBMs are strictly forward-progress machines. Once excavation is complete, the outer steel shield is often abandoned in place (buried), while the valuable internal components (motors, gearboxes, PLCs) are stripped, dismantled, and transported back through the finished tunnel structure.