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GSI to host webinar on stabilization of soil slopes with anchored geosynthetics

Events | September 23, 2019 | By:

The Geosynthetic Institute (GSI) will sponsor a webinar, “In-Situ Stabilization of Soil Slopes Using Nailed or Anchored Geosynthetics,” on Oct. 9, from 11:30 a.m. to 1 p.m. EDT. Geosynthetic Materials Association (GMA) member companies and their employees receive discounted rates on all GSI webinar and short course registrations.

The sliding of soil slopes in the form of localized landslides represents an annual loss of $2–5 billion in America along with an associated 25 to 50 casualties. Theoretically, such failures are readily analyzed; e.g., simplified Bishop for rotational surfaces and Corps of Engineers wedge method for translational surfaces. For existing slopes which cannot be completely reconstructed due to structures at the top or toe of the slope, however, an in situ remedial method is necessary. This webinar focuses on a geosynthetic placed on the existing soil’s surface and then nailed or anchored into the soil beyond the potential failure surface. Originally called “anchored spider- netting,” the method provides several benefits, each of which increases the factor-of-safety (FS), for example:

  • increases soil friction
  • increases soil cohesion
  • nails penetrate the failure plane
  • geosynthetic force is added along potential failure plane
  • moment due to geosynthetic at ground surface exists

Numeric examples including the above listed benefits are given illustrating the resulting increases in FS values.

Original field trials in the 1980s are shown using a gathered knit geotextile and hand-driven soil nails. Interestingly all activity then ceased for some twenty years. Perhaps the 1986 patent on the technique thwarted the method’s implementation? Since 2010, however, at least ten manufacturers, contractors or developers have taken up the concept using different soil covering materials as well as various nailing or anchoring systems. Each of these newer methods will be illustrated with a comparison made at the conclusion of the webinar.

Participants will become familiar with details of this in situ soil slope stabilization method. It is indeed a juxtaposition of geosynthetics and ground modification. The factor-of-safety improvements are illustrated by means of theory and examples, as well as description of the commercially available approaches to the technique. This webinar will hopefully lead to mitigating the large number of shallow soil slope failures along our highways as well as on private and public lands.

The webinar is intended for owners of sensitive or quasi-stable soil slopes in both the public and private sectors; federal, state and regional geotechnical, transportation, and environmental engineers; engineers from municipal districts and townships; private and municipal land developers, architectural and landscape designers; general civil consulting engineers; testing laboratories servicing these organizations; representatives of geosynthetic materials companies; ground modification contractors and installers of in-situ soil slope stabilization methods; academic and research groups; and others desiring technically related information on this important aspect of our constructed infrastructure.

The webinar’s instructor, Dr. Robert M. Koerner, is professor emeritus of civil engineering at Drexel University, and founder and director emeritus of the Geosynthetic Institute.

Webinars cost $200 for GSI and GMA members, and $250 for nonmembers. Successful completion of a multiple-choice test after the webinar carries 1.5 professional development hours (PDH).

For more information or to register, visit

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