TBM Bertha, used for opening the tunnel in the Alaskan Way Viaduct Replacement Project is on the move again, after major overheating problems that caused the machine to remain still for more than a year. The machine is expected to reach an access pit so that crews can perform necessary repairs.
Bertha, the powerful tunnel boring machine, used in the opening of the main tunnel of the Alaskan Way Viaduct Replacement Project, was put in operation in 2013. She was expected to cover an underground distance of 2 miles, however stopped operating due to overheating problems after 1,000 feet. Since December 2013, workers have been trying to dig a 120-foot-deep access pit, facing significant ground sinking issues.
Bertha must now dig through 14 feet of unreinforced concrete to reach the access pit, before crews can remove her front section for repairs. There is major concern that the machine may overheat again and stop working, but Lynn Peterson, secretary of the Washington State Department of Transportation, said the machine's temperature is being monitored. Ground movement is also being monitored, but no signs of displacement have been traced so far.
The $3 billion project was designed as a replacement to the SR99 viaduct, heavily damaged by a magnitude-6.8 earthquake in 2001, and is already two years behind schedule.
Source: seattlepi.com
The Alaskan Way Viaduct replacement is a transportation megaproject in the City of Seattle, Washingt...
The Bertha Tunnel Boring Machine, at 57.5 feet (17.5 m) in diameter, is the world's largest TBM. On...
Tunnel-boring machines deployed at tunneling projects across the U.S. are using Twitter to share obs...
Completion of the new Highway 99 tunnel, originally planned for late 2015, has been delayed even fur...
Last Tuesday in Seattle, the world’s largest TBM started moving again after nearly eight weeks of st...
Whether you live in the U.S. or not you will find the following tunnels that are currently being bui...
The Tunnel Boring Machine (TBM) that was used to achieve Atlanta's water supply tunnel overcame ext...
The second of the two tunnel boring machines (TBM) that were used for the excavation of HS2’s longe...
According to the Washington State Department of Transportation (WSDOT), crews on January 2 managed t...