Traffic Tunnelling: Pioneering
tunnelling technology up to 19 meters.
Herrenknecht Traffic Tunnelling Technology (Ø > 4.20m) is being used for traffic infrastructure tunnelling solutions around the world. Herrenknecht equipment is always adapted to the tunnelling project in question, taking into consideration geological and hydrological conditions. For soft, mixed, hard, dry or water saturated soils - Herrenknecht has the right solution for any constellation.
Herrenknecht Earth Pressure Balance (EPB) Shields are in their element in soft ground. Cohesive and incohesive soils with high clay or silt content and low water permeability provide the ideal conditions for EPB tunnelling.
Fluid-supported Mixshields are specialists for multi-layered, complex geologies, particularly those with a high water content, and are a patented trademark of Herrenknecht. This functioning principle is particularly well-adapted to heterogeneous soils: Thanks to the center-free drive with the floating bearing of the cutting wheel and the modular structure of the machine, the operating mode can be altered to suit the soil conditions in the tunnel.
For use in solid rock, the principle of the gripper is both the most simple and most effective technique. The single gripper machine braces itself against the rock using two gripper plates. Then, hydraulic cylinders push the cutterhead into the tunnel face at high pressure, grinding it with cutter rings. Double gripper machines work according to the same principle, using four hydraulically operated gripper plates.
Single Shield TBMs are the right choice for brittle or soft rock. In shield tunnelling, the tunnel is lined with concrete segments. To tunnel forward, the hydraulic thrust cylinders of the Single Shield TBM push against the last installed lining ring.
Double - or Telescopic - Shields unite the principles of the Gripper and the Single Shield TBM, enabling fast excavation even in varying rock formations.
Herrenknecht shields with partial face excavation can achieve remarkable advances in the most diverse geological conditions and for a wide range of different tunnel profiles. The same basic equipment can be fitted with both excavators and roadheaders.
