The function of cover systems is to prevent the infiltration of water into the landfill and to control the release of gases from the landfill. Previous studies of this problem have utilized small-scale soil samples, often compacted under conditions different to those used in the field. Although these tests have been invaluable in clarifying the problem of freeze-thaw, extending the results of such experimental studies to prototype landfills is problematic.; This study provided a large-scale laboratory investigation of landfill cover system behavior under the influence of repeated freeze/thaw cycles. The laboratory experiment utilized a 1.8 square meter tank, of approximately 2 meter depth. The tank was loaded with clay according to the specifications required of landfill cover systems.; The simulation included seven designs for layered cover systems and two designs for clay liners without layering. Simulation of each design included two or three freeze/thaw cycles. The depth of frost penetration was measured between 27.5cm and 32cm for all designs tested. The predicted value for frost penetration (from analytical expressions) did not correspond well to the laboratory measurement. However, the laboratory measurements compared well with the limited data available from field sites. Measurements of frost heave as a function of moisture content showed that the magnitude of heave was directly related to the moisture content of a soil layer. It was found that HDPE and Polyurea geomembranes had an insulating effect on the clay liner beneath the geomembranes. However, there was negligible difference between the insulation capacities of the HDPE and Polyurea geomembrane. This study included an analysis of cracks using fractal geometry. Fractal dimensions between 1.12 and 1.23 have been measured for the four cracks. These fractal dimensions are comparable to the fractal dimension of a coastline and suggest curves that mildly plane-filling.; Under consideration is the need to develop useful tools and techniques for improving the design and construction of landfills while still trying to reduce the construction budget.
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