Some new research on the Newmark Displacement Method for earthquake-induced landslides indicates that the method may be on the unconservative side. The Landslide Blog provides a short summary of the paper by Li et al. (2018) that was recently published in the journal Landslides. Their research was based on physical models on a shake table, comparing the results of the model experiments with a Newmark analysis. The paper should be worth a read for geotechnical engineers practicing in seismically active areas. It sounds like some additional study is needed to confirm these results and if they are true, propose different ways of analyzing earthquake-induced landslides.
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.
Earlier this month, there was a massive slope failure on the "Sea to Sky" highway in British Columbia. It is interesting to note that this same area had a large rockslide in 1965, and a photo of this failure is featured on the cover of the classic text, Rock Slope Engineering by Hoek and Bray. The media played up the aspect that this highway is one of the only ways to access the site of the 2010 Winter Olympic games hosted by Vancouver.
The composite image above shows the book cover and the recent rockslide event (Photo credit: Erik Eberhardt of the University of British Columbia by way of Dave’s Landslide Blog). Dave has done a fabulous job collecting photos, facts and links from around the web. In a follow up post, he added some additional photos and discussion. I recently came across an article that described how the highway originally was slated to have a tunnel bypassing the slide, but that the price tag of $200 million (CAN?) for a 1-km stretch killed the project.