The LA Times is reporting that the California bullet train project may be facing significant budget and schedule issues, largely because of a 13.5-mile tunnel beneath Pacheco Pass east of Gilroy. The article reports that the current budget for the 54-mile segment between Gilroy and Chowchilla is $5.5B, but experts that they interviewed for the story put the cost of the twin-bore tunnel itself at between $5.6 to $14.4B. Geological and geotechnical drilling and testing are currently underway for the tunnel which will be up to 1,000 feet below ground through the challenging Franciscan Complex. Don’t forget about the challenges of a seismically active area and at least one major fault crossing. The designers and engineers for that project are going to have their hands full with that one!
In Washington D.C., the D.C. Water and Sewer Authority (D.C. WASA) finalized a lont-term plan in 2002 aimed at reducing combined sewer outfalls into the Potomac River and its tributary, the Anacostia River. A major portion of this plan is a $2.2 Billion (US) deep tunnel program to handle excess stormwater flows and prevent the combined sewage from being discharged into the environment. Read on for a map and more info. (Photo of Anacostia River, by D.C. WASA)
The proposed tunnel to replace the seismically deficient Alaskan Way Viaduct in Downtown Seattle is no stranger to controversy. This article highlights recent discussions regarding the cost of the project. Washington Governor Chris Gregoire declared […]
WSDOT released an update on February 7 with some conclusions regarding the blockage that has stopped the Alaska Way Viaduct Tunnel Boring Machine, Bertha’s progress since December 6. Now they don’t think it was necessarily the well casing after all.
They cite two factors that contributed to the blockage. First, the cutterhead was clogged with material. You can see an cool short video of a worker unclogging the cutterhead. Not terribly dramatic, but still cool. The second factor was increased temperatures inside the equipment. STP discovered damage to a seal that protects the machine’s main bearing. They are still determining how the repairs will be done.
If you want to follow the chronology of this issue, read below for summaries and links to previous updates from WSDOT. And Check out the videos too! [Source: WSDOT]