Simulation of Arable Soil Compaction Behavior by Finite Element Method and Image Processing Technique

Soil compaction refers to process that increases density, decreases volume and continuity of pores, decreases water and air permeability, and increases mechanical strength. One of important parameters for evaluation of soil compaction is pre-compaction stress, which is often considered as stress at threshold of soil compaction. Plate sinkage test is an appropriate method for determining soil pre-compaction stress. In this research, for determining pre-compaction stress the experimental test of plate sinkage was used on a sample of arable soil (sandy clay loam) at the level of 15% moisture content based on dryness and density 1500 kg.m-3. Then mechanical properties of soil was determined. Plate sinkage test was simulated as the form of two-dimensional and symmetric in Abaqus software and the pre-compression stress was also predicted by this method. Also, the amount of stress and displacement changes in the transverse and longitudinal layers of arable soil were analyzed. There was a high correlation (R2 =0.99) between the data extracted from the simulation model and the experimental data. Examination of compressive stress and displacement in different layers in the soil depth showed that the amount of stress and displacement in layers close to load level is more and decreases amount of stress and displacement as it progresses to the lower layers. Also, in this research, image processing technique by MATLAB software has been applied as a method to estimate soil compaction. As a general conclusion, the finite element method and image processing can be used for assessment of compacted region of soil.