Devil’s Slide is an infamous landslide along California’s Highway 1 or Pacific Coast Highway near Pacifica, just south of the San Francisco Bay area. Caltrans’ Devil’s Slide Tunnel project is an effort to bypass that slide and make the heavily traveled roadway safe for drivers and to eliminate the maintenance and traffic hassles caused by slope failures blocking the road. We first covered the project back in September of 2007 when the tunnel portion of the project commenced. In that post, you can find a Google Earth KML File showing the location of the tunnels and the new bridges associated with the project. In this post, Iâ€™ll provide you with some updated progress information as well as some background on the geotechnical and other aspects of the project. More links and videos are at the end of the post. (Photo by Kim Komenich, San Francisco Chronicle). […]
In the mountains of Peru a tunnel-boring machine named â€œPacha Mamaâ€ is grinding through the heart of the Andes under rock as deep as 6,890 ft. It is carving away at a 20.2-kilometer-long tunnel through the South American Continental Divide to deliver water to arid coastal farmland.
This is a really interesting project, known as the Los Olmos project, and a nice little article. Normally for a civil tunnel project you drill geotechnical holes beforehand to know what kind of material you’re dealing with. In this case, because of the depth, they don’t have that luxury, so all decisions will be made on the fly. The depth of the tunnel creates some very challenging rock mechanics and logistics problems as well! (Illustration by Odebrecht)
ENR reports that a Tunnel Boring Machine or TBM is stuck for the second time in two weeks on Pittsburgh’s light rail expansion project dubbed the North Shore Connector Project. As we described in a previous post, the project will consist primarily of a tunnel underneath the Allegheny River. The drilling began the week of March 3 and has been progressing at a rate of 30-ft/day or 5-ft/day faster than the original goals. Read on for a location map of the project, or download the Google Earth KMZ file showing the project area. (File photo of TBM)
Today, Tuesday, February 26, 2008, the Svalbard Global Seed Vault is scheduled to start operating on the remote island of Spitsbergen, Norway in the Svalbard Archipelago. The location is only about 1000km (625 miles) from the North Pole. The Global Seed Vault will house duplicates of seeds from known species of plants from all over the world in case a natural or other disaster destroys the original species. [Editor] Read on for more details. Photo by Mari Tefre/Svalbard Global Seed Vault [/Editor]
The proposed railway tunnel will link Spain and Morroco underneath the Straits of Gibraltar. The depth of the straits ranges from 1,000-ft to nearly 3,000-ft. To put that in perspective, the English Channel is only 150-ft deep, and the Chunnel is another 130-ft below the sea floor. (Photo by chodaboy)
In keeping with our theme of rising costs on tunnel projects, the Brightwater sewage-treatment plant and treated waste pipeline project in King County Washington (Seattle area) is now up to at least $1.84 billion according to the lead consultant on the project. The treated waste pipeline is 13 to 14-miles long and at depths of 40 to 440-ft! It is being constructed nearly entirely by TBM. One source of delay was due to a tunneling subcontractor not being able to get parts (ball bearings?) because they were all being requisitioned by the US War Department for use in military equipment in Iraq and Afghanistan. Click through for information sources and links.
The Port Authority of Allegheny County (Pittsburgh, Pennsylvania) has a major transit improvement project dubbed the North Shore Connector. Its main components are twin bored tunnels 1.2 miles long that will connect the Port Authorityâ€™s Light Rail Transit system, the T, 1.2 miles from the Gateway Subway Station underneath Stanwix Street and the Allegheny River to the North Shore. It will travel under the river and provide three new stations and allow for future improvements beneficial to future development and continued downtown revitalization. The $435 million project is making news recently for cost increases, drawing comparisons to Bostonâ€™s Big Dig much to the dismay of the Port Authority. Read on for project maps, links and more info.
The International Journal of Geoengineering Case Histories has formally announced their second issue. Apparently when I posted about it previously, they had only two of the four papers.
This second issue contains four case histories that come with additional downloads. In particular, check out Dr. Edmund Medley’s Paper on the 2006 Hawaii Earthquakes. He has some neat photos including some in 3-D (more about his 3-D photos).
- Design Process of Deep Soil Mixed Walls for Excavation Support: Example of paper with digital data
- Effect of Dredging and Axial Load on a Berthing Structure
- Geological Engineering Reconnaissance of Damage Caused by the October 15, 2006 Hawaii Earthquakes: Example of an Online Database
- Lack of Maintenance Compromises Tunnel Structural Safety
Thanks to approximately $100 million from President Bush’s proposed 2009 budget, the $1.8 billion project creating a light-rail line from downtown Seattle to the University of Washington is likely to break ground some time this year. The project will involve twin bored tunnels on the order of 3 miles in length. It is scheduled to open for use in 2016.
There is another notable tunnel project associated with the Seattle Light Rail, known as the Beacon Hill tunnel which I have blogged about before.
The US House of Representatives passed legislation approving a national tunnel inspection program. This of course came about as a result of a fatal accident from 2006 in a tunnel on Boston’s Big Dig project where a concrete ceiling tile fell on a car killing one person. More after the break.