Investigation of Sandy Soils Grouting-ability with Sodium Silicate Chemically Grout

Chemically grouts are usually injected in soils for increasing of strength or reducing of permeability in which suspended grout could not pass through the small voids of soil mass and filteration of grout particle. Chemically grouts are injected easily to voids of soils due to liquidity and non-suspending of them. One of important factors of these grouts is their viscosity in which controls the grouting potential of them, so that increasing of grout viscosity reduces its grouting ability. In this paper the grouting ability of sandy soils with a chemically grout is investigated. For evaluation of the soil grouting potential, samples with 4 cm in diameter and 100 cm in height were constructed and then injected. Sand samples with four different particle size (coarse, medium, fine and silty sand) and three relative densities (loose, medium and dens) were injected by sodium silicate grout with three different viscosities (water to sodium silicate ratio). Tests results showed that, particle size has the greatest effect on the grouting and the other mentioned parameters depend on this factor. Reducing of particle size decreases the grouting potential of soil, so that adding 50 % silt to soil (50 % silt and 50 % sand) impossible to fully grouting of the sample without fracturing the sample.