Abstract
Under deep mining conditions, fractured rock masses are subjected to sustained high confining stress and elevated water pressure, resulting in complex seepage evolution. This study conducts triaxial seepage experiments on single-fractured sandstone to investigate the coupled effects of confining pressure, water pressure, fracture roughness (JRC), and fracture aperture under a unified stress–seepage framework representative of deep high-confined water environments. Results show that seepage flow increases linearly with water pressure but decreases nonlinearly with confining pressure, exhibiting a three-stage evolution involving elastic deformation, elasto-plastic transition, and compaction equilibrium, with a clear stabilization threshold. Elevated water pressure reduces the effective normal stress on fracture surfaces, thereby weakening fracture closure, particularly in rough fractures where asperity degradation contributes to permeability enhancement. Comparative analyses reveal that fracture roughness and aperture jointly control permeability magnitude, attenuation rate, and stabilization behavior. Quantitative relationships between stabilized permeability and key fracture parameters are established, providing a concise, parameter-based description of fracture seepage under high-stress conditions. The findings offer practical insights for predicting seepage evolution and mitigating floor water inrush risks in deep mining environments.
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The datasets used and/or analysed during the current study available from the corresponding author on reasonable request.
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Funding
Financial support for this work is provided by the National Natural Science Foundation of China (52574176, 52474161), the Postdoctoral Research Foundation of China (2025T180509), and the Fundamental Research Funds for the Central Universities (2024ZKPYNY01).
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H.T. and C.Z. conceived the research idea and designed the experimental framework. S.J. and S.F. were responsible for the sample preparation, including the fabrication of auxiliary splitting devices and the fracture surface characterization using 3D scanning technology. R.W. performed the triaxial seepage experiments, collected the data, and conducted the preliminary data analysis. C.Z. and H.T. developed the theoretical models and performed the in-depth analysis and interpretation of the results. The main manuscript text was written by C.Z. with significant contributions from H.T. and R.W. All authors, including S.J. and S.F., reviewed, critiqued, and approved the final version of the manuscript.
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Tu, H., Wu, R., Jia, S. et al. Seepage characteristics of fractured sandstone under deep high-confined water and mining-induced stress. Sci Rep (2026). https://doi.org/10.1038/s41598-026-42285-6
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DOI: https://doi.org/10.1038/s41598-026-42285-6
