Underground Leak Sealing Restores Coal Terminal Operations

The collapse of a Himalayan highway tunnel in Uttarakhand, India, trapped 40 workers, sparking a challenging rescue operation. The incident occurred on November 12, 2023, and the workers are reported to be in good health, […]

On September 17, CALTRANS and Kiewit Pacific held a "tunnel excavation celebration" to kick off the start of tunnel construction on The Devil’s Slide Tunnels project on California State Route 1 (the Pacific Coast Highway) in San Mateo County between the town of Montara to the south and the city of Pacifica to the north. The project involves the creation of a separated two-lane road, one lane in each direction. This road will pass through twin tunnels, over twin bridges and connect with an existing non-separated two-lane road at each end. The new road will be approximately 6,500 feet long, made up of the roughly 4,000-foot twin tunnels, the 1,500-foot north approach road (which includes the 1000-foot parallel bridges), and the 1,000-foot south approach road. Upon completion, the new road will bypass geologically unstable portions of existing Route 1, sections of roadway subject to lengthy closures, high maintenance costs over the years, and risk of permanent failure. Thanks Geology.com for the heads up. [Read on for more background, photos, maps, and movies!] (Images by CALTRANS)

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The Devil’s Slide Tunnel Project was originally scheduled to open at the end of 2012, but it has been delayed slightly to an early 2013 opening. If you look at some recent photos, you can hardly tell that there is anything left to finish. I’ve been following this project since it started, since to me it represents the essence of geoengineering, with important roles played by geotechnical engineers, geological engineers, hydrogeologists, and of course geotechnical contractors and tunneling specialists.  I thought it would be interesting to list a few of the posts I’ve written about the project over the years and present a bit of information I only recently learned.  Click through for more. [Image: kxyoung on Flickr]

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