Earth Fissures in the News
Last week was the annual American Council of Engineering Companies of Arizona Roads and Streets Conference in my home town of Tucson, Arizona. Its a transportation themed conference as you might guess, but there are usually a few geotechnical-type presentations. This year, there was an excellent presentation on the SR 87 Landslide that occurred about 1-year ago on the highway between Phoenix and Payson. The presentation was given by Keith Dhalen, PE with AECOM , Wayne Harrison, RG also with AECOM and Scott Neely, PE with Terracon . Read on for my recap of the presentation. (Photo by ADOT via AZGS)
According to Lee Allison’s Blog (Lee is the head of the Arizona Geological Survey and the Arizona State Geologist), the AZGS has released earth fissure maps of 4 Arizona Counties suitable for planning purposes. Read on for more details.
On March 21, 2008 a landslide caused the closure of Arizona State Route 87 between Payson and Phoenix near mile post 224. So far there are no official estimates as to the size, but based on aerial photos, it appears to be at least 50,000 sq-ft in plan. The offset at the head scarps was approximately 2-meters (6.6-ft) according to AZGS Geologists on site. It appears to have been a rotational slide as the toe of the landslide heaved the southbound roadway up by as much as 1-meter (3.3 ft). There was an existing soil-nail retaining wall on the slope that was destroyed by the slide as well. Lateral deformations can be seen in photos of the median barrier and the roadway striping. The deformations extended into the northbound lanes as well. More photos and links after the break. (Photo by ADOT)
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