Geosynthetics are layered with soil, rock, and other materials to form reinforced earth structures such as modular block retaining walls, steepened slopes, or venier-lining systems. Typically, an earth structure in a landfill includes a geosynthetic liner to prevent ground contamination. Problems occur when ground movement causes structural components to shift, or “pull out,” causing system failure.

ASTM D 6706, Standard Test Method for Measuring Geosynthetic Pullout Resistance in Soil uses a laboratory model to determine pullout resistance of geosynthetic components in earth structures. Approved August 10 by ASTM Committee D35 on Geosynthetics, the method applies to all geosynthetics and soils and is useful when comparing geosynthetics and soil types for design, acceptance, and R&D.

D 6706 was developed by an ASTM task group of geosynthetic manufacturers, engineers, testers, and government agencies. “The new test method provides a standardized set of guidelines for conducting this important performance test which is used in part in the design of reinforced earth structures,” said task group chairman Robert H. Swan, Jr., president and CEO of SGI Testing Services, LLC, Atlanta, Ga.

Chief author of the method, Swan specializes in geotechnical and geosynthetic system performance. Application of guidelines for standard-sized pullout boxes and specimens can result in consistent testing between labs and ultimately improved, safer earth structures, he affirmed.

For further technical information, contact Robert H. Swan, Jr., SGI Testing Services, LLC, Atlanta, Georgia (phone: 404/256-9939). Committee D35 meets Jan. 21-24 in Dallas, Texas. For meeting or membership details, contact Pat Picariello, manager, Technical Committee Operations, ASTM (phone: 610/832-9720). //

Copyright 2001, ASTM