Effect of water content on mechanical and electrical characteristics of the water-rich sandstone during freezing

In western China, artificial freezing is the main effective technology to excavate the deep water-rich strata in mining. The mechanical strength of the frozen wall is the focus of attention in artificial freezing design. Uniaxial compression test was performed on the frozen sandstone samples to investigate the effect of temperature and water content on uniaxial compression strength (UCS); the results indicated that UCS of the wet sandstone increased linearly with the decrease of temperature from − 5 °C to − 20 °C, and the growth rate of the mechanical strength firstly increased and then decreased with increasing water content. Additionally, samples were scanned by X-ray computed tomography (X-ray CT) to explain the variation of macro-mechanical strength of frozen sandstone. The electrical resistivity of frozen sandstone was then measured with decreasing temperature under different water content conditions. The relationship between electrical resistivity and UCS of the frozen sandstone was determined from experimental data, which showed that the UCS of the frozen sandstone increased logarithmically with the increase of electrical resistivity under various water contents.