Understanding the compressive behaviour of soils is essential to predict the alterations that might occur in soil structure when submitted to stress caused by agricultural machinery. Soil compression curve has been used to understand the process of compression. Pre-compaction stress (σpc) and compression index (Cc) are important parameters which can be obtained from compression curve and are used in evaluating soil load support capacity and its susceptibility to compaction, respectively. Plate sinkage test (PST) could be used in determining soil compressive parameters (σpc, Cc). In this research, the stress-sinkage behaviour of a silty clay loam soil treated with long-term incorporation of sewage sludge (SS) with four application rates (0, 25, 50 and 100 t ha-1) was simulated using the finite element method (FEM). The soil was modelled as a two-dimensional axisymmetric structure using ANSYS. The soil material behaviour was assumed as a linear viscoelastic material. Soil shear relaxation kernel function was obtained from the results of confined compression relaxation test and direct shear box test using well-defined relations between elastic properties. The FEM model was verified against the experimental results obtained using the PST on repacked soil samples. The FEM model successfully simulated the trend of soil stress-vs.-sinkage under PST; however, the average predicted σpc value was smaller by a factor of two. The σpc values derived from the experimental date over-estimated the applied preload, on average, by 69%; whereas excellent agreement between the FEM simulated values and the preload was demonstrated for the SS amended soils. The σpc indicates the maximum effective stress to which the soil has been subjected; whereas in the experimental results, the total stress was used to obtain the σpc. Therefore, the σpc values obtained from FEM simulation data and the experimental data could be considered as effective and apparent σpc, respectively.
کلید واژگان :pre-compaction stress; compression index; finite element analysis; viscoelasticity; plate sinkage test
ارزش ریالی : 300000 ریال
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