Volume 2, Issue 1 — Year 2025 — Article e100025

Nazila Danesh¹; Ali Taghizadeh²; Mohsen Valinejad³; Mehdi Kouhdaragh⁴

1. Department of Civil Engineering, Islamic Azad University Malekan Branch, Malekan 5561788389, Iran
2. Department of Civil and Environmental Engineering, Urmia University, Urmia 5756151818, Iran
3. Department of Civil and Environmental Engineering, Urmia University, Urmia 5756151818, Iran
4. Department of Civil Engineering, Islamic Azad University Malekan Branch, Malekan 5561788389, Iran

This study examines the creep behavior of loose, high-plasticity soils under constant shear stress through a comprehensive laboratory investigation. High-plasticity loose soils, characterized by their substantial water retention capacity and susceptibility to significant deformation, pose critical challenges in engineering applications due to their time-dependent behavior under sustained loads. To analyze these behaviors, we conducted 25 laboratory tests, including Atterberg limits, particle size distribution, direct shear tests, and oedometer analysis. The results indicate that creep deformation in high-plasticity soils progresses in three stages (i.e. primary, secondary, and tertiary) with the rate and magnitude of deformation significantly influenced by factors such as applied stress levels, moisture content, and soil structure. Observations reveal that increased water content and higher stress levels accelerate creep deformation, while the soil's mineralogical composition governs its overall response. The findings also highlight the necessity of incorporating time-dependent behavior into the design and analysis of geotechnical projects involving high-plasticity soils.

Creep behavior, Loose soils, High plasticity, Shear stress, Laboratory evaluation