Volume 32, Issue 3 (May 2009)
A Review of the No Erosion Filter Test
The no erosion filter (NEF) test is widely accepted as the most appropriate filtration test for the substantiation of suitable critical filters in embankment dams. No consistent standard method for NEF testing has been introduced; thus, various schemes have been implemented for performing NEF tests. This paper reviews critically the antecedent research on the NEF testing procedure. The cornerstone hypothesis of NEF testing and the evolution of the testing method are reviewed. The significance of different parameters encountered in the testing procedure and their relevance and importance in the judgment are elaborated. Practical guides for proper conduction of the NEF test are recommended throughout this paper.