Author(s): Erdene Ganbold and Enkhjargal Tungalag

Abstract: Expansive soils, characterized by their high shrink-swell potential due to swelling clay minerals like montmorillonite, pose significant challenges to infrastructure stability, particularly under cyclic loading and moisture fluctuations. This study aimed to evaluate the behavior of expansive soils under cyclic loading conditions and examine the effects of stabilization using lime and fly ash. The objectives included analyzing the influence of cyclic stresses and moisture variations on soil deformation, assessing the role of stabilization in improving soil performance, and developing predictive models. Soil samples were collected and characterized for their physical and mineralogical properties. Swelling behavior was measured under saturated conditions, and cyclic triaxial tests were conducted at loading frequencies of 0.5 Hz, 1 Hz, and 2 Hz for 50 cycles under varying moisture conditions.The results revealed that untreated expansive soils exhibited high swelling pressures (450 kPa) and swelling percentages (14%), with residual strain reaching 6.8% after cyclic loading. Lime stabilization at 5% reduced the swelling percentage to 7%, while fly ash stabilization at 8% achieved a significant reduction to 4.5%. Under cyclic loading, fly ash-treated soils demonstrated the lowest residual strain (2.6%) and the highest dynamic shear modulus (32 MPa). Moisture variations increased the residual strain in untreated soils by 40%, while stabilized soils, particularly fly ash-treated, showed only a 10% increase. Statistical analysis confirmed significant improvements with stabilization (p< 0.05).Fly ash outperformed lime in reducing swelling, improving resistance to cyclic loading, and mitigating moisture effects. These findings highlight the effectiveness of fly ash as a cost-effective stabilizer for expansive soils, with practical implications for infrastructure development in regions with variable climatic conditions.While laboratory conditions provide a controlled environment for studying expansive soils, real-world field-scale experiments remain essential. The inclusion of factors such as temperature and drainage effects, often encountered in natural environments, is critical for better understanding and applying stabilization methods effectively.

DOI: 10.22271/27078361.2024.v5.i2a.59

Pages: 55-60 | Views: 62 | Downloads: 15

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