Cutting Tool Advancements for long Tunnel Drives and Geologic Extremes

Extreme tunneling conditions call for the most robust TBM cutting tools possible—whether that includes hard and abrasive rock, long-distance tunnels of 15 km or more, or high water pressures.  Extreme conditions can be defined as those conditions that result in poor advance rate, catastrophic disc cutter failure, or unacceptable wear life of a disc cutter. While disc cutters are widely considered a mature technology, there is room for growth and development, spurred on by increasing numbers of projects in difficult ground.

At China’s Yin Han Ji Wei project for example, hard rock, combined with face collapses, damaged cutters and prompted engineers to design a more robust cutter ring to survive in the most severe conditions. It is not just hard rock prompting design changes: at New York, USA’s Delaware Aqueduct Repair, a Single Shield TBM is boring in rock with water pressures up to 20 bar. The 19-inch diameter disc cutters utilize a pressure compensation mechanism that has been bench-tested up to 34 bar in order to excavate under the high pressures. These are just a few of the developments currently being tested...

Related articles:

Issue 2011-08

Remote Disc Cutter Monitoring in Tunnelling

Monitoring TBM cutter wear without accessing the cutting face was once something discussed as a future goal in tunneling. This advancement is now near reality with a new remote cutter monitoring...

more
Issue 2013-04 EPB Cutters

The Next Revolution in EPB Cutters – New Cutter Designs make an Impression in Mixed Ground

Six TBMs including three Robbins EPBs are tackling on this project in the underground of Mexico. The emergency project is needed urgently to prevent potential flooding of Mexico City’s wastewater...

more
Issue 2014-07 Turkey

Terratec delivers TBM for Istanbul Metro

Terratec has announced a new Tunnel Boring Machine delivery for Istanbul Metro in Turkey at the end of August after the successful performance of the workshop testing. The official ceremony was held...

more
Issue 2018-06 Japan

Hiroshima Heavyweight launches on Expressway Line 5

On September 18, 2018, a Robbins slurry machine, measuring 13.7 m in diameter, made its first cut into hard rock

Due to the project location there were also restrictions on delivering the TBM—in order to meet controlled transportation limits within the city, the TBM had to be divided into small transportable...

more
Issue 2015-02

Marathon Machines

From abrasive rock to fault zones to water inflows, geologic challenges become more common as tunnel lengths increase. In rock tunnels over 15 km long, a host of challenges may meet a TBM, requiring a...

more