Strengthening Low Plastic Soils Using MicroFine Cement Through Deep Mixing Methodology

Abstract

The objective of the research work was to evaluate the settlement trait, modulus of subgrade reaction, elasticity, and shear strength of low plastic soil strengthened using Cement Deep Mixing technique. This is accomplished by performing modeled Plate Load and Unconfined Compression Test, respectively. For achieving the objective, a tank of size 75 cm × 75 cm × 75 cm was fabricated in which soil was compacted at different degree of saturation as 80 and 100% of optimum moisture content and using deep mixing assembly, soil–cement columns of different lengths as 100 and 200 mm were drilled and grouted. The assembly created comprised of cutter blade at the base of a solid pipe for facilitating drilling of the hole into the soil, and perforations all around the pipe facilitates grouting action during withdrawal. Filz theory (Geo-Front Congr ASCE 162(1):1–13, 2005) was adopted for deep mixing. Five columns of 5 cm diameter each out of which four columns at a spacing of 25 cm c/c and one under the footing were formed. Microfine cement slurry with water: cement ratio of 1.2 was used for grouting. Low plastic soil treated with microfine cement showed an appreciable reduction in the settlement as compared to untreated soil and was found to be adequate.