The influence of saturation and loading angle on sandstone damage characteristics after freeze-thaw cycle

Abstract

The strength deterioration and fracture tendency of freeze-thaw rock determine the construction and operation safety of rock engineering. This article conducted compression-shear composite load tests on sandstones with various saturations to examine the failure law of rocks in cold climates and the contributing elements of strength degradation. It was found that with an increase in saturation and loading angle, the compressive strength and elastic modulus dropped. The concept of freeze crack threshold and saturation threshold was proposed. The peak shear stress was negatively correlated with saturation and positively correlated with loading angle. The σ_CI (crack initiation stress) and σ_CD (crack damage stress) in the saturated state were only 39.91% and 45.18% of those in the dry state. Serious damage occurred at high saturations, which is consistent with the scanning electron microscopy results. The σ_CI and σ_CD under 30°loading angle are 49.72% and 42.91% of those under uniaxial, respectively. This is mainly due to the change of the failure mode from tensile-shear failure to combined tension-shear failure, and finally to single-shear failure. A strength prediction model was established based on sandstone damage characteristics. The research results have important reference value for rock engineering design in frigid climates and complex load environments.

Keywords:

• Freeze-thaw sandstone
• saturation
• loading angle
• damage characteristics
• prediction model

Disclosure statement

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

Data availability statement

All data supporting the findings in this study are available from the corresponding author on reasonable request.

Additional information

Funding

This research was financially supported by the National Natural Science Foundation of China (Grant nos. 51974145 and 52274206).

Notes on contributors

Shihao Yuan

Shihao Yuan, male, is a doctoral candidate at Liaoning University of Engineering and Technology. He is mainly engaged in research work in rock mechanics.

Jiaxu Jin

Jiaxu Jin, male, Doctor of Engineering, Northeastern University, Professor. He is mainly engaged in scientific research in environmental geotechnical engineering.

Xiaoli Liu

Xiaoli Liu, male, Doctor of Engineering, Tsinghua University, Distinguished Researcher. He studied at the Swiss Federal Institute of Technology in Lausanne, and his main research direction is THMCB multivariate multiscale correlation process of geospheric dynamics.

Shaohua Li

Shaohua Li, male, Distinguished Associate Researcher, Doctor of Engineering, Northeastern University. He is mainly engaged in research work in rock mechanics.

Bing Liang

Bing Liang, female, Professor, currently Secretary of the Party Committee of Liaoning Technical University. She is mainly engaged in research work in engineering mechanics and seepage mechanics.