Applying Nano Material in Improving Bearing Capacity of Soils

Passive method is a new way in stabilizing loose soils. This method is as a type of interlocking of soil structure. In order to successfully improve in this method, it is necessary to achieve proper penetration length and increase the shear strength of parameters. Previous studies have shown an increased resistance to liquefaction and decreased permeability due to colloidal Nano silica injection. In this research, sandy soil was mixed with silt in 5, 10 and 15 percent. Then, specimens in dry and saturated conditions were placed under the influence of Nano silica colloid. For determining geotechnical properties of improved specimens direct shear test was performed in three situation (dry, saturated, and grouted). Also, for studying drainage condition after improving constant head permeability test was carried out. The results showed that by adjusting ionic strength and rheometry properties such as viscosity and gel modulus, it is possible to achieve proper penetration length and obtain the required strength for injection in silty sand with a high non plastic fines content. Besides, with the injection of Nano silica colloid, the amount of vertical settlement in the samples decreased significantly. Also, the amount of permeability of the stabilized materials showed a decreasing trend.