Prediction of Soil Compaction by Small Tractor Using Finite Element Method

The main characteristics of agricultural soil are soft and unsaturated, the soil bulk density and moisture content are not only main parameters but also main factors influencing the soil compaction, and they are variable. In order to manage the soil effectively in the field, on the basis of particular soil type, a two-dimensional (2D) finite element model was developed as a tool that can be used to predict the soil compaction caused by small tractor. In the model, the soil compaction was expressed as a nonlinear function of both normal stress and maximum natural shearing strain. The initial values of the soil bulk density and the moisture content, and the stress path were considered in the model. The finite element model was verified with the field test data. The result showed that the soil bulk density and major principal stress could be predicted well in an initially loose soil profile of silty loam in north areas of China.