Dynamic soil properties of nanoparticles and bioenzyme treated soft clay

Abstract

Among various soil improvement methods, stabilization using traditional additives (cement, lime, flyash, etc.) is very often used in soft clay soils. In recent times, nontraditional additives are used as a partial or a full replacement to the traditional additives for reducing the detrimental effect of excessive addition of these to the earth. The present study is focused on developing such a combination of non-traditional additives, which minimizes the use of traditional stabilizers. The study aims to evaluate the soil behavior under dynamic loading before and after the soft soil is treated with the optimum of Nano silica and Bioenzyme along with 1% of cement (cured for 28 days). Strain controlled cyclic triaxial tests, and piezoelectric bender element tests were conducted to evaluate the effect of treatment on various dynamic properties of the clay in particular shear modulus (G), damping ratio (D) and the small strain shear modulus (Gmax) respectively. The stabilization improves the shear modulus and damping ratio of the soil because the stress dissipation and energy absorption are more due to particle densification, pore volume reduction, and better bonding between the cemented particles. The results of cyclic triaxial and bender element tests indicate that the nano-silica in the presence of bioenzyme and cement can be a highly powerful technique in improving the moduli of the soil.