In October of 2009, a massive landslide in the Nile Valley, near Yakima, Washington, took out a portion of Washington SR 410 and impacted the Naches River as well. This video from WSDOT shows what emergency response was required to get temporary traffic restored on a detour and get a more permanent detour constructed.
A massive landslide has destroyed at least a quarter-mile of State Route 410 in Washington State, about 10 miles from Naches in Yakima County. It has also damaged about 12 structures including residential homes and quarry buildings and diverted the Naches River. The media has been referring to it as the Naches Slide, but the personnel from the Washington Department of Natural Resources, Division of Geology and Earth Resources who have began investigating the slide as well as WSDOT are calling it the Nile Landslide. (Photo by WAStateDNR-DoGaER)
Click through for photos and videos. For more info on the slide, check out the Sliding Thought Blog, an unofficial blog by Isabelle Sarikhan of the WAStateDNR – Division of Geology and Earth Resources “aka” the Washington Geologic Survey. She’s been actively investigating the slide along with some colleagues.
A report has been released by the NYSDOT on the Scoby Hill Landslide which has impacted a 4.2-mi improvement project of Route 219. The report, dated May 20, 2008 was headed to an FHWA peer review panel.
The Feds were call in to help because of the unusual nature of the landslide. The slip surface is very deep, approximately 30-m (100-ft) below the surface and below all of the design phase investigations. And the remolded shear strength of the silty clay forming the slip surface was only 12-14 degrees.
Read on for more details of the slide. (Photo by NYSDOT)
A large landslide has closed SR 14 east of Cedar City, Utah. UDOT expects that the road will be closed for up to 2 weeks for cleanup and to ensure that the slope is safe. Boulders up to an estimated 20 tons are now blocking the road and will likely need to be blasted down to a smaller size. A UDOT spokesman interviewed on the video shown after the break estimate the size of the slide at 700 to 800-ft long and 10 to 12-ft thick.