Completed side-hill retaining wall for the SR 264 Second Mesa project in Arizona. Photo by Bharat Khandel, ADOT by way of NCS Consultants, LLC

Side Hill Retaining Walls – Part 2

Completed side-hill retaining wall for the SR 264 Second Mesa project in Arizona. Photo by Bharat Khandel, ADOT by way of NCS Consultants, LLCIn this part 2 of 2, various types of retaining walls are examined as possible alternatives in a side-hill retaining wall situation. These include conventional wall types such as CIP walls, MSE walls, gravity walls and soldier pile walls and some less conventional approaches such as lighweight concrete fill, hybrid soil-nail and geofoam wall systems, ground improvement and micropile walls.

Part 1 of this Side Hill Retaining Wall article covered the definition, significance, problems and failure modes, investigation techniques, analysis, and construction considerations of side hill walls. A PDF version is now available for download as well. Click through for the article and the download link!



Updated – DFI Committee Looking for Soil Nail Data

[Update 2008-06-25 8am] I saw somewhere that they were looking for this info by July 1, but I don’t know where. I couldn’t find a deadline on the DFI Committee page. Maybe they erased it. [/Update]

The Tiebacks & Soil Nailing Committee of the Deep Foundations Institute is collecting data on soil nail wall performance. From the Tiebacks & Soil Nailing Committee page:

A request for information has been distributed to all DFI members, academia and various other industry members.  Information being sought includes typical project, geotechnical and wall geometry information, design and analysis methods and software, construction and monitoring duration, settlement and lateral deformation data, and nail strain gauge data.  Click here to download the PDF form to enter your project’s information to the committee for compilation and analysis.



ADSC 2008 Faculty Workshop Wrapup

Robert Thompson of Dan Brown and Associates has posted a wrapup of the 2008 ADSC Faculty Workshop. They had 20 Civil Engineering faculty attend the event. The field demonstration day was hosted by DBA at the Trial’s Training Center in Sequatchie, Tennessee. Apparently that site is Dan’s hobby. Read more about the workshop itself and also read Robert’s post about the field demonstration day including photos. In the photo at right (Robert Thompson, DBA) you can see the Statnamic test setup for a drilled shaft. A little more about the event:

Long Foundation and Hayward Baker have installed examples of several foundation and retaining structures, including drilled shafts, micropiles, and soil nails. During the field day demonstrations, the attendees will observe additional installations, load tests, and non-destructive testing.


Geologic Hazards

Landslide on Arizona SR 87 Closes Highway

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)


Press Releases

ADSC Joins with FHWA to Conduct Hollow Core Soil Nail Research

The ADSC [Editor] (Association of Drilled Shaft Contractors) [/Editor] will join the FHWA as co-sponsors of a research project to develop a database of the available grout-to-ground bond stress of Hollow Core Anchors (HCAs) and to determine if correlations exist with traditional solid bar, drill and grout soil nails. The FHWA and the ADSC are interested in documenting the performance of HCAs in soil nail wall type construction and identifying methods of quality assurance so that HCAs can be specified with confidence in appropriate applications, both temporary and permanent. [Editor] Photo of hollow core nail installation underneath an existing bridge abutment, courtesy of NCS Consultants, LLC. Read on for the rest of the release. [/Editor]