Analysis of pore structure characteristics and strength prediction model of coarse-grained soil based on fractal theory

• Published in: Environmental earth sciences Vol. 82; no. 24; p. 592
• Main Authors: Liu, Yao, Deng, Hongwei, Wang, Peng, Yu, Songtao
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01.12.2023; Springer Nature B.V
• Subjects: Biogeosciences; Coarse-grained soils; Compressive strength; Correlation analysis; Earth and Environmental Science; Earth Sciences; Economic benefits; Environmental Science and Engineering; Fractal geometry; Fractal models; Fractals; Freeze thaw cycles; Freeze-thawing; Geochemistry; Geology; Hydrology/Water Resources; Magnetic properties; Magnetic resonance; Mechanical properties; Modelling; NMR; Nuclear magnetic resonance; Original Article; Parameters; Pore size; Pore size distribution; Pores; Porosity; Prediction models; Scanning electron microscopy; Size distribution; Soil; Soil mechanics; Soil porosity; Soil properties; Soils; Stability analysis; Terrestrial Pollution; Correlation model; Fractal dimension; Pore structure; Coarse-grained soil
• ISSN: 1866-6280; 1866-6299
• DOI: 10.1007/s12665-023-11298-z

The stability of the dump is related to the safe operation and economic benefit of the mine, and the mechanical properties of its constituent soils are important basic data to evaluate its stability, while the changes in the mechanical properties are influenced by its internal structure. Nuclear magnetic resonance and scanning electron microscope techniques are used to obtain the pore size distribution and microscopic image characteristics of coarse-grained soil samples under the influence of freeze–thaw, respectively. Based on the fractal theory, the variation law of fractal dimension and box dimension of different apertures is analyzed and studied. In order to select reasonable pore structure parameters, linear fitting correlation analysis was used to determine the large pore ratio and medium pore fractal dimension as the model construction parameters. The correlation model between the dual pore structure parameters and uniaxial compressive strength (UCS) of coarse-grained soils was established. The results show that, with the increase of freeze–thaw cycles, the distance among the particles in the coarse-grained soil samples is increased, the connectivity among the pores is enhanced, the proportion of large pore, surface porosity, and box dimension are all increasing gradually. The proportion of macropores in the samples increased gradually, the medium and large pores showed good fractal characteristics. At the same time, the strength correlation model based on pore structure parameters can also achieve a good prediction of coarse-grained soil UCS.