Experimental investigations on the elastic parameters and uniaxial compressive strength of slate under freeze-thaw cycles

摘要

In this study, uniaxial compression experiments with seven different bedding angles and six numbers of freeze-thaw cycles were conducted to investigate the influences of freeze-thaw cycles on the elastic parameters and the uniaxial compressive strength of slate. The laws of the elastic parameters, uniaxial compressive strength and failure characteristics were analysed, and a new uniaxial compressive strength prediction model that considers the bedding angle and the number of freeze-thaw cycles as control variables was established and verified using the experimental data. The results showed that the uniaxial compressive strength, elastic modulus and shear modulus decreased exponentially with an increasing number of freeze-thaw cycles. However, the Poisson's ratio increased linearly with an increasing number of freeze-thaw cycles. The uniaxial compressive strength initially decreased and then increased with increasing bedding angle. There are three forms of failure occurred during the tests: when the bedding angle was 0°≤β ≤ 26.6°, the splitting failure and shear failure occurred at the same time; when the bedding angle was 26.6°≤β ≤ 83.0°, sliding failure occurred along the bedding plane; and when the bedding angle was 83.0°≤3 ≤ 90°, splitting failure occurred along the axial direction of sample.