Experimental Application of Fractal Theory into Selection of Subgrade Filling Materials

Abstract

To investigate the settlement deformation of subgrades, we used fractal theory and soil section technology to study the original foundation soil, and soils filled with 4%, 8%, 12%, 16%, 20% and 24% of A material. The results show that under consolidation pressure of 500 KPa and after one dry-wet circulation, the fractal dimension was 1.7 in the original soil, 1.78 in the soil filled with 4% A material, and 1.93 in the soil filled with 24% A material. Along with the increased dopant amount of A material, the fractal dimension of soil mass gradually increased, but after the dopant amount reached 24%, the increasing rate was very slow. With the increased addition of A material, the compression deformation gradually weakened, but after the dopant amount reached 24%, the changing rate was very small. We derived a prediction model between the dopant amount at a certain particle size and the fractional dimension. This model can be used to predict the dopant amount at a certain size. The reasonableness of this model when using single size was validated via engineering practice.