Raw aerial video from CNN.com
Photos from the WAStateDNR – Department of Geology
The Oregon Route 20 project resulted in the original design-build contractor being terminated from the project after bridge pier bents began shifting from construction activities in a landslide-prone area. "Design-build is more of a risk […]
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)
Back in March of 2008 there was a landslide that closed SR 87 in between Phoenix, Arizona and Payson. It’s been of great interest to me since it is in my state and affected a highway. I was hoping my firm (NCS Consultants, LLC) might be asked to work on the remediation through our on-call contract but it didn’t happen. Its probably for the best, it sounds like it’s been a troublesome geotechnical engineering problem. Fast forward to last week, and the slide area was in the news again because the slope is still moving and apparently causing some additional deformation of the roadway. (Photo by ADOT)
I had heard about this a while ago through our ADOT contacts, but I make it a policy not to take advantage of my contacts through my day job for GeoPrac.net content (not without permission anyway). So I didn’t want to blog about it until it hit the mainstream media. Last week, the Arizona State Geologist blogged about the SR 87 slide moving again, as did Ken through his AEG Arizona Section blog. It was even covered on one of my favorite blogs, Dave’s Landslide Blog. I finally have a chance to wade through these blog posts and some of the reports and videos to present a summary of the situation, available information and offer my own perspective. (More after the break)
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