DEFORMATION AND FAILURE IN WET CLAY SOIL .2. SOIL BIN EXPERIMENTS

Tests of soil cutting by wide tines were conducted in wet clay soil. Force-displacement curves were obtained and the soil deformation patterns were observed and analysed with the help of a painted grid. The tine experiment showed that the soil deformation pattern depended on the tool rake angle (the angle between the tine face and the horizontal soil surface). For small rake angles, soil deformed in a narrow zone leading up from the tool tip and there were tensile cracks near the tool tip. For bigger rake angles, soil in front of the tool failed by distortion with small shear lines and big soil-soil slip lines. For rake angles equal to or bigger than 90· an elliptical wedge formed. Passive earth pressure theory did not describe the deformations observed in these wet clay soil conditions. © 1993 Silsoe Research Institute.