A Method for obtaining Three-dimensional Soil Failure Profiles used in modelling Soil-Tool Interactions

Three-dimensional soil failure profiles were obtained by superimposing two-dimensional soil profiles. Tests were conducted in a laboratory soil bin with a glass side. Two parallel tines, one along the centreline and the other by the side of the glass were used. The tine near the glass could be shifted inward for different test runs. The two-dimensional soil failure profiles due to the forward movement of flat tines were observed through the glass side. The soil profiles at changing lateral position of the tine were recorded and synchronised before the superimposition. To confirm the uniformity of the soil preparation for each test run, the central tine was arranged with the facility to obtain the force-time measurements of the test runs. Mathematical expressions for two-dimensional soil failure profiles along three principal orthogonal planes were also obtained. The predicted soil failure boundaries of the horizontal plane were well correlated with those obtained by visual observations as well as by the computed values of force-time signals obtained for different lateral tine positions. These realistic three-dimensional failure profiles can be used in the development of mathematical models of soil-tool interactions.