Soils engineering laboratory supervisor, New York State Department of Transportation, Albany, NY
Geotechnical engineer, California Department of Transportation, Sacramento, CA
Pages: 12 Published: Jan 1987
The use of geotextiles in geotechnical engineering has brought about many varying theories and approaches. These theories and approaches vary from a broad-based general requirement to a project-by-project design approach.
Provided in this paper are the methods of selection, testing, and the recommended use of geotextiles for drainage applications as defined by the New York State Department of Transportation (NYS DOT) and the California Department of Transportation (Caltrans).
Caltrans approaches the use of geotextiles for drainage in the same manner as they approach aggregate filtration for drainage, with the advantages of a filter with tensile properties being incorporated. The Caltrans Standard Specifications address geotextile use from a range of properties associated with drainage rather than singular absolute parameters.
Caltrans approaches geotextile acceptance on a project-by-project basis. While accepting letters of certification concerning geotextile properties, they also carry on a general control testing program for acceptance.
NYS DOT addresses the use of geotextiles from a preapproved list of materials of five basic categories. This concept provides the basis for NYS DOT use of geotextiles in normal (that is, nonsevere) applications. Therefore, the contractor has a choice of several geotextiles based on availability, economics, and experience in use. The characteristics for the drainage application category are given in the discussion. Also given are the conditions which require specific design considerations in critical applications.
The two points which evolve from the discussion are that both agencies have limited drainage applications to nonwoven materials, and through differing empirical approaches both agencies have developed cost-effective and efficient usage of geotextiles in drainage applications.
geotextiles, drainage, permeability, soil retention, woven, nonwoven, apparent opening size, filtration, strength, empirical, Approved List, needle-punched, needle-formed, melt-bonded, permittivity, geotextile testing
Paper ID: STP20053S