Effect of Non-plastic Fines Content and Gradation on the Liquefaction Response of Chlef Sand

• Published in: Transportation infrastructure geotechnology 2024-08, Vol.11 (4), p.2638-2670
• Main Authors: Krim, Abdallah, Brahimi, Abdelkader, Bouri, Djamel Eddine, Nougar, Benali, Lamouchi, Basma, Arab, Ahmed
• Format: Article
• Language: English
• Subjects: Building Materials; Compression; Compression tests; Compressive strength; Confining; Correlation; Engineering; Fines; Foundations; Geoengineering; Geotechnical Engineering & Applied Earth Sciences; Grading; Hydraulics; Liquefaction; Mechanical properties; Mixtures; Particle size distribution; Pore pressure; Pore water pressure; Prediction models; Pressure; Pressure effects; Relative density; Sand; Shear strength; Silt; Soil mechanics; Soil resistance; Specific gravity; Technical Paper; Triaxial tests
• ISSN: 2196-7202; 2196-7210
• DOI: 10.1007/s40515-024-00394-7

This study explores the impact of non-plastic fines content, initial confining pressure, and grading characteristics on the undrained shear strength and excess pore pressure of sand-silt mixtures; a series of undrained compression triaxial tests were carried out on reconstituted Chlef sand (Algeria) samples with different percentages of silt content ( F c  = 0, 5, 10, 15, and 20%), at an initial relative density (RD = 50%) subjected under three different confining pressures ( p ′ c  = 20, 50, and 100 kPa). Observations from these tests unveiled intriguing insights. Notably, it was discovered that soil specimens with lower fines content and higher initial confining pressures showed increased resistance to liquefaction. Conversely, liquefaction resistance diminished under conditions of higher fines content and lower initial confining pressures. Moreover, the analysis of test results underscored the substantial influence of gradation on the peak shear strength and maximum excess pore pressure of sand-silt mixtures. This suggests that the distribution of particle sizes within the mixture plays a pivotal role in its mechanical behavior and susceptibility to liquefaction. Furthermore, the study’s findings revealed the presence of straightforward correlations between various parameters. These correlations include those between peak shear strength ( q peak ), maximum excess pore pressure (Δ u max ), fines content (Fc), initial confining pressure ( p ′ c ), and specific grading characteristics such as D 10 , D 30 , D 50 , D 60 , C u , D 10R , D 50R , and C uR . These correlations offer valuable insights into the interplay of factors affecting the mechanical properties of sand-silt mixtures, aiding in the development of predictive models and engineering solutions for infrastructure projects.