Effect of silt fines on the undrained monotonic behavior of compacted tuff soil

• Published in: Arabian journal of geosciences 2025, Vol.18 (1)
• Main Authors: Ezziane, Mohammed, Henni, Ahmed Djafar, Denine, Sidali, Benyahia, Bilal Ahmed, Boumezerane, Djamalddine
• Format: Article
• Language: English
• Subjects: Cohesion; Dry density; Earth and Environmental Science; Earth Sciences; Fines; Moisture content; Original Paper; Silt; Soil; Soil stresses; Soil water; Soils; Triaxial tests; Tuff; Water content
• ISSN: 1866-7511; 1866-7538
• DOI: 10.1007/s12517-024-12149-2

The present study explores the influence of silt content on the undrained monotonic behavior of compacted tuff. All undrained triaxial tests were performed at both relative densities D r  = 50 and 90% and compacted with the optimum water content on tuff soil mixed with silt in the range of 0 to 50%. Experimental results show that adding fines content (FC) up to 20% increases the resistance of dense compacted tuff ( D r  = 90%) by about 35% for 100 kPa of confining pressure, and the addition of 10% silt fines results in a maximum increase of 15.71% in the medium dense state specimen ( D r  = 50%). The deviator stress reveals a decrease by adding more than 20% of silt. Moreover, the soil cohesion was found to attain maximum values with the optimum silt percentage of FC = 10% for medium-density samples ( D r  = 50%) and FC = 20% for dense samples ( D r  = 90%), respectively. Finally, the study showed a direct correlation between the cohesion of the soil prepared in a dense state ( D r  = 90%) and the soil’s maximum dry density (MDD). In particular, the maximum dry density corresponds to a higher cohesion.