The effect of tracked-vehicles multi-passes on rut depth and soil properties

Soil mechanical properties depend, among other things, on moisture content and compaction level. The mobility of a vehicle traveling over soft soil is determined by soil mechanical properties and terrain geometry. After a vehicle passes over soft terrain, the compaction level of the soil in its traces may change, thereby changing its mechanical properties. Multi-passes are when a vehicle passes over the same route or trace multiple times. In this case, the mechanical properties of the soil also depend upon the number of passes made. In military operations and precision agriculture, vehicles frequently travel over soft soil in each other's traces. The goal was to develop a model to predict changes in the soil mechanical properties and rut depth caused by multi-passes of tracked vehicles. The resulting model also includes an empirical factor, which can be calibrated during multi-pass tests. Experiments of multi-passes were conducted using several heavy tracked vehicles and soil conditions. A reasonable correlation was achieved between the predicted soil properties and those measured during the experiments.