The Fabricated Geomembrane Institute (FGI) has produced a new guideline titled, “Subgrade Requirements for Fabricated Geomembranes.” This guideline details the proper preparation of the subgrade for the installation of all fabricated geomembranes. This document is written such that these guidelines can be picked up by an engineer or specifier and put into a specification for subgrade condition and requirements. Color pictures of both acceptable and unacceptable subgrade preparations and protrusions are provided to give the user a visual depiction of what is described in the text.
The subgrade requirements for preventing water pressure buildup below the liner are addressed in this guideline. This is an important consideration in preventing the geomembrane from being lifted off the subgrade by groundwater or gas buildup. This document can be found at http://www.fabricatedgeomembrane.com/?page_id=180 and is available for use by the industry.
The FGI is housed at the University of Illinois at Urban-Champaign. Dr. Timothy D. Stark is a professor of civil and environmental engineering at the University of Illinois at Urbana-Champaign with an expertise in geotechnical engineering. Stark has been teaching, researching and consulting on geosynthetics, stability of manmade slopes and design of waste containment facilities for more than 15 years.
