Geotextiles have been extensively used as filters in geotechnical engineering for over 5 decades. The main reasons for this widespread utilization are that they are manufactured products with repeatable properties, are easy to install and to transport to distant working sites and can substitute natural filter materials where they are scarce or their use is prohibited by environmental regulations. Despite their technical and commercial success, the behaviour of geotextile filters can be quite complex, particularly in the case of nonwoven geotextiles, some reasons being that they are thin and compressible materials, with a complex micropore structure. This paper reviews and discusses some factors that can influence nonwoven needle-punched geotextile filter behaviour. The influences of confinement and partial clogging on filter pore dimensions are discussed based on results from special laboratory tests and theoretical approaches. Limitations of such approaches in simulating actual field conditions are also discussed. The study highlights the relevance of the factors presented and identifies procedures to quantify their influences and to reduce the possibility of filter poor performance.

Keywords: Filters, Geosynthetics, Geotextiles, Nonwovens,

Submitted on May 29, 2020.
Final Acceptance on June 23, 2020.
Discussion open until December 31, 2020.
DOI: 10.28927/SR.433351