Mechanical and electrical properties of coarse-grained soil affected by cyclic freeze-thaw in high cold regions

• Published in: Journal of Central South University 2020-03, Vol.27 (3), p.853-866
• Main Authors: Qu, Yong-long, Ni, Wan-kui, Niu, Fu-jun, Mu, Yan-hu, Chen, Guo-liang, Luo, Jing
• Format: Article
• Language: English
• Subjects: Coarse-grained soils; Compressive strength; Deformation; Dry density; Electrical properties; Electrical resistivity; Engineering; Evaluation; Exponential functions; Freeze thaw cycles; Freeze-thaw durability; Geotechnical engineering; Image analysis; Mechanical properties; Mechanical tests; Metallic Materials; Modulus of deformation; Moisture content; Parameters; Soil freezing tests; Soil mechanics; Soil properties; Strain hardening
• ISSN: 2095-2899; 2227-5223
• DOI: 10.1007/s11771-020-4336-8

To evaluate the geotechnical properties of coarse-grained soil affected by cyclic freeze-thaw, the electrical resistivity and mechanical tests are conducted. The soil specimens are prepared under different water contents, dry densities and exposed to 0-20 freeze-thaw cycles. As a result, the stress-strain behavior of the specimen ( w =14.0% and ρ d =1.90 g/cm 3 ) changes from strain-hardening into strain-softening due to the freeze-thaw effect. The electrical resistivity of test specimen increases with the freeze-thaw cycles change, but the mechanical parameters (the unconfined compressive strength q u and the deformation modulus E ) and brittleness index decrease considerably at the same conditions. All of them tend to be stable after 7−9 cycles. Moreover, both the dry density and the water content have reciprocal effects on the freeze-thaw actions. The failure and pore characteristics of specimens affected by freeze-thaw cycles are discussed by using the image analysis method. Then, an exponential function equation is developed to assess the electrical resistivity of specimens affected by the cyclic freeze-thaw. Linear relations between the mechanical parameters and the electrical resistivity of specimens are established to evaluate the geotechnical properties of the soil exposed to freeze-thaw actions through the corresponding electrical resistivity.