What is a Tunnel Boring Machine? A Tunnel Boring Machine (TBM) is a large, specialized machine used for the excavation of tunnels through various types of soil and rock. These ...

Voids can occur above a tunnel machine when too much dirt falls into the rotating cutterhead, and the soil overhead settles. Over-excavation is a risk in tunnel-boring operations worldwide.

On Saturday, a tunnel boring machine (TBM) so large that it looks like something out of Thunderbirds was dedicated in the city of Seattle. “Bertha,” as it’s known, is the world’s largest ...

Crews will stop pumping groundwater from the soil surrounding stranded tunnel-boring machine Bertha, after state surveyors found Sunday that the Alaskan Way Viaduct is sinking in an uneven manner ...

Then the tunnel-boring machine named after the former first lady freshened up a bit and wormed back underground, ready to dig a massive hole beneath the Anacostia River toward the doorstep of ...

A welder prepares for the tunnel-boring machine “Angeli” to break through a wall of dirt at the 2nd Place/Hope Street Station in downtown Los Angeles. (Irfan Khan / Los Angeles Times) ...