Shear behaviour of Canadian marine clay/geomembrane interface under freeze–thaw cycles

Abstract

The influence of the number of freeze–thaw (F–T) cycles on the interface shear behaviour of a compacted marine clay (Leda clay)/smooth high-density polyethylene (HDPE) geomembrane is investigated in this paper. Shear tests are performed on samples subjected to various numbers of F–T cycles: zero, one, two, three, five and ten. The test results show that the interface shear strength of the Leda clay/smooth HDPE geomembrane is lower than that of Leda clay. The interface shear strength of the Leda clay/smooth HDPE geomembrane decreases with increasing number of F–T cycles. Furthermore, the interface shear friction angles of the Leda clay/smooth HDPE geomembrane are significantly reduced within the first three F–T cycles. The reduction in strength beyond the three F–T cycles is negligible. The total decrease in the shear strength of the samples that are not subjected to an F–T cycle compared to that of samples subjected to ten F–T cycles is 18·3, 17·6 and 13·6% under a vertical stress of 150, 250 and 350 kPa, respectively.