Nano-Bio Soil Improvement (NBSI) with Micro-, Nano-, and Pico- Typha latifolia: a green material approach

Soil stabilization is a method of improving weak soils by adding different additives. Nano additives and materials represent a new technology and a revolution in soil mechanics and geotechnical engineering, used for soil stabilization, a branch of soil improvement. This research evaluates the particles of Nano- and Pico-Typha solution as a new biomaterial for soil improvement using nano and pico scales, bio, and soil mechanics tests. The research investigates the changes in soil mechanical properties after the addition of Nano and Pico Typha solution as a Nano-Bio Geotechnics (NBG) technique, comparing the properties of the soil before and after stabilization. To control and characterize the size and nature of the particles studied in this research, SEM tests were performed after the nano production process. To check the particle dimensions and structure before and after the nano production process, XRF and XRD tests were performed. After converting particles from micro to nano scale, there are also smaller pico particles. The research studied the properties of Khavaran clay soil by adding Typha and Nano Typha as a Nano-Bio additive in different percentages of 3%, 5%, and 7%, and in curing times of 1, 7, and 28 days. The results showed that the uniaxial resistance of clay increased from 50 kPa to 12 times its initial value by adding 7% Nano-Typha after 28 days of curing. The maximum deviator stress of the soil increased by 10.1, 14.07, and 15.9 times its initial value in confining stresses of 100, 200, and 300 kPa, respectively, by adding 7% Nano-Typha after 1 day of curing. The cohesion and friction angle of the soil stabilized with 7% Nano-Typha solution increased by 2.22 and 6.3 times, respectively, compared to clay soil after 1 day of curing.