A study of the engineering characteristics of reinforced loose sand by modified nano-Si materials

In order to change the low strength and low erosion resistance of loose sand, the reinforcement of loose sand is exaimed in this paper, which is based on nano-silicon material and takes polyacrylamide as modifier. Under the joint action of different concentrations of nano-silicon material and different amount of modifier, the unconfined compressive strength, shear strength and disintegration characteristics of the the consolidated loose sand are studied respectively, and the reinforcement mechanism is analyzed. The experimental results show that the unconfined compressive strength, shear strength and anti-disintegration ability of the modified nano-silica material are greatly improved. When the concentration of nano-silicon is constant, the compressive strength and shear strength of sand increase at first and then decrease with the increasing modifier content. When the concentration of nano-silicon is 20% and the amount of modifier is 0.2%, the compressive strength reaches the maximum 970 kPa. When the concentration of nano-silicon is 20% and the amount of modifier is 0.3%, the adhesion force and friction angle are 173.2 kPa and 39.3 °, respectively. In the anti-disintegration test of the consolidated loose sand, when the concentration of nano-silicon is more than 20% and the amount of modifier is more than 0.1%, the disintegration rate of the reinforced sand sample is less than 50% after 8 days of invading in water. When the concentration of nano-silicon is 20% and the amount of modifier is 0.2%, the stabilized sand will not disintegrate. Comprehensive test results suggest that the concentration of nano-silicon solution of 20% and the amount of modifier of 0.2% are the best proportions of the modified nano-silicon material to strengthen loose sand.