Frictional behaviour between smooth and rough geomembranes, various soils and geotextiles

To improve the environmental protection new waste disposal sites nowadays are covered at bottom and on top by waterproof sealings. Those sealings are made of a combination of mineralic soils and a layer of HDPE-material (High density Polyethylen). For the safety of the slopes stability and the durablility of the combinated sealing, the friction behaviour between the different materials of the sealing is very important. In many tests, the friction between geomembranes with rough and smooth surfaces, sand, silt, clay and geotextiles respectively has been investigated by using shear boxes of 10 cm by 10 cm and 30 cm by 30 cm length. Depending on the test results, recommendations are made for the shear-parameters in the investigation of the slope stability and other geotechnical calculations.