EXPERIMENTAL DETERMINATION OF VARIABILITY IN PERMEABILITY OF SANDY SILT SOIL MIXED WITH FLY ASH IN PROPORTIONATE

This paper presents the experimental determination of variability in permeability of sandy silt soil by blending with fly ash. The grain size, porosity, structure of the soil, specific gravity of the soil, viscosity and temperature are important factors in varying the permeability of the soil. Permeability is the flow conduction property of the soil. The void ratio with in the soil plays a vital role in varying the permeability. By blending with finer grains like fly ash in the soil with sandy silt the permeability will vary. This phenomenon can be observed through experimentation in the laboratory. The variation in the drainage property of the soil also observed. This paper includes all the variation in the flow property of the soil (sandy silt soil) by adequate mixing of the fly ash. Fly ash is a major solid by-product of the combustion of pulverized coal in thermal power plants. Five soil samples with different mixes of sandy silt and fly ash were obtained for comparison. Rigorous laboratory tests were performed to determine the individual properties. Tests such as Specific Gravity Test, Atterberg Limit Test (Liquid Limit, Plastic Limit and Plasticity Index), Relative Density Test, Particle Size Analysis, and Permeability Test were performed. From the results of these tests, it is observed that increase in fly ash content in soil Maximum Dry Density (MDD) decreased and Optimum Water Content (OMC) increased. Permeability is decrease with increase in fly ash in sandy silt soil.  The decrease in permeability of sandy silt soil helps in stabilizing this soil and consequently increases the shear parameters of the sandy silt soil.