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Double Breakthrough Connects the Brenner Base Tunnel Beneath the Alps
Both main tubes of the Brenner Base Tunnel have broken through at the Austria-Italy border, about 1,400 meters below the Brenner Pass. […]
Tunnel Boring Machine
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Yangtze River TBM Rescue
China has set a new benchmark in underground rescue operations with its remarkable recovery of a stalled 16‑m diameter tunnel boring machine (TBM) beneath the Yangtze River. During construction of the 6.4‑km Jiangyin–Jingjiang Yangtze River […]
Available Resources
Nicholson Legends and Iconic Projects: A 70-Year Celebration of Geotechnical Excellence
Nicholson Construction, one of GeoPrac.net’s long-time sponsors and a pillar of the geotechnical industry, recently celebrated its 70th anniversary with a two-part webinar series titled “Nicholson Legends and Iconic Projects.” The series featured six senior […]
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Bertha Demo Period Done, Resumes Mining
The Bertha tunnel boring machine has resumed chewing away beneath Seattle after a ‘suspension for cause’ order from WSDOT shut it down in January following two safety incidents. The BTM began tunneling with some conditions […]
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Bertha Tunneling to Resume 1 Month Later Than Planned
The Seattle Tunnel Partners JV announced last month that tunneling on the Alaska Way Viaduct Replacement project will resume a month later than originally planned. The Bertha TBM will resume mining on December 23 after […]
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Update on Access Pit for Repairing Bertha TBM
There hasn’t been much to report recently for the Alaskan Way Viaduct Tunnel Project in Seattle. As you probably know, Bertha has not advanced since about December of 2013 after drilling through an abandoned steel […]
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Conceptual Plan for Excavation to Repair Bertha TBM
Seattle Tunnel Partners has released a conceptual plan showing what the excavation of the pit will look like to repair the damaged Bertha Tunnel Boring Machine. See below. A pit 120 feet deep and 83 […]
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Plan for Bertha Repair Submitted, Archaeological Surveys Underway
Seattle Tunnel Partners and WSDOT are moving forward with the plans to excavate a 120 foot deep shaft to repair the Bertha Tunnel Boring Machine. Unfortunately, there are archaeological issues since the project team did […]
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Attempting to Remove the Pipe Blocking Bertha
The Seattle Tunnel Partners JV is attempting to remove the rest of an 8 inch diameter steel well casing that has been blocking the Bertha tunnel boring machine since December 8, 2013. The upper 55 […]
Articles
Bertha – The World’s Largest Tunnel Boring Machine
Perhaps you’ve heard of Bertha, the World’s Largest Tunnel Boring Machine or TBM? She’s currently working her way underneath Downtown Seattle, excavating the Alaska Way Bored Tunnel to replace the aging Alaska Way Viaduct. This $2 Billion megaproject is an incredible feat of engineering on so many levels. I was in Seattle in September for the Association of Engineering Geologists annual meeting, and was fortunate enough to attend a field trip to see the launch pit and Bertha before she began her tunnel drive. It was an unforgettable experience for this engineer! In this article I give an overview of the project and Bertha herself, discuss some of the geotechnical features, and share my photos and video. Check it out!