Enhancement of geotechnical properties of loess using nano clay and nano-iron oxide

• Published in: Environmental earth sciences 2024-07, Vol.83 (13), p.418, Article 418
• Main Authors: Zhang, Zhichao, Hou, Yifei, Li, Ping, Wang, Jianyun
• Format: Article
• Language: English
• Subjects: Biogeosciences; Cementation; Clay; Compressibility; Compression; Compressive strength; Differential settlement; Earth and Environmental Science; Earth Sciences; Economic impact; Environmental Science and Engineering; Geochemistry; Geology; Hydrology/Water Resources; Iron; Iron oxides; Landslides; Loess; Nanomaterials; Nanoparticles; Nanotechnology; Original Article; Penetration resistance; Permeability; Principal components analysis; Shear strength; Soil environment; Soil properties; Solifluction; Surface energy; Surface properties; Terrestrial Pollution
• ISSN: 1866-6280; 1866-6299
• DOI: 10.1007/s12665-024-11716-w

Loess typically has a metastable structure that is susceptible to collapse upon wetting. Collapse and other associated problems, such as landslides and differential settlement, cause serious damage to the infrastructure constructed on loess, including the loss of human lives. Nanomaterials have been widely used in many fields because of their small size, large specific surface area, and high surface energy. They have also been used to reduce or eliminate the poor engineering properties of soil. However, until now, there have been few attempts to use nanomaterials to stabilize loess. This study aimed to investigate the effect of nanoparticles on the geotechnical properties of loess and to reveal the mechanism of the effect of nanoparticles on loess. Two nanomaterials, nano-clay (K10), and nano-iron oxide, were used to stabilize loess, because the addition of them may have little negative impact on the soil environment as they are the main components of loess. The compressibility, collapsibility, permeability, shear strength, and other properties of stabilized loess were investigated. The results show that the addition of nanoparticles can increase the shear strength, improve the resistance to compression and creep, and decrease the collapsibility and permeability of loess. This is attributed to the filling and cementation effect of nanoparticles. The shear strength, unconfined compressive strength (UCS), and resistance to penetration of K10-stabilized loess were higher than those of loess stabilized with nano-iron oxide. On the other hand, nano-iron oxide performed better than K10 in reducing the collapsibility, compressibility, and creep of loess. Additionally, the optimum content was determined in this study based on the principal component analysis (PCA) to consider various geotechnical properties of stabilized loess. The optimum content of K10 and nano-iron oxide was suggested to be 3% and 1.5% (w/w), respectively, considering both the strengthening effect and economic cost. The results are expected to provide useful information for the application of nanomaterials in loess stabilization.