Field study of wrinkles in a geomembrane at a composite liner test site

摘要

The variation in length of the longest hydraulic features (connected wrinkles) formed in an exposed black highdensity polyethylene (HDPE) geomembrane liner observed at different times of the day and in different seasons over multiple years is presented for both a 3% base slope and 3H:1V side slope at the Queen's University Experimental Liner Test Site (latitude of 44°34=N and longitude 76°39=W). The longest wrinkle observed on the 0.15 ha base was about 1500 m. The longest wrinkle observed on the 0.17 ha slope was about 2000 m. The length of connected wrinkles is shown to be primarily related to solar radiation, although the soil and ambient temperature played a role in maintaining wrinkles in the afternoon as solar radiation decreased. Wrinkles of less than 20 m connected length were observed for geomembrane surface temperatures of less than 30 °C and solar radiation of less than 600 W/m ~2. Wrinkles exceeding 500 m in connected length were observed for geomembrane temperatures between about 30 and 62 °C and solar radiation between 600 and 1100 W/m ~2. The vast majority (about 85%) of wrinkle heights were between 0.04 and 0.08 m with the average wrinkle height being 0.06 m and a maximum wrinkle height of about 0.18 m. The manually measured wrinkle widths around noon (when there was the greatest number of wrinkles) ranged between about 0.20 and 0.43 m, but most of the wrinkles were between 0.23 and 0.36 m with a mean of 0.29 m (standard deviation 0.05 m). The data from this study suggest that a reasonable estimate of mean wrinkle width would be about 0.2 to 0.3 m. The size of the area constraining the geomembrane is shown to affect the connected wrinkle length. Calculations of leakage for the wrinkle lengths and widths observed are reported to be consistent with what has been reported for landfills in North America.