A experiment study on the weakening effect in sandstone roof at a submerged coal mine

The mechanical properties of the surrounding rock at the island working face have been significantly altered due to extended exposure to high-salinity mine water, raising concerns over the safety of mining operations. This research seeks to conduct a thorough analysis of the mechanical properties of water-saturated roof rock in deep underground mining conditions, with particular emphasis on sandstone samples typically found in these settings. A series of dynamic loading tests were conducted on sandstone specimens with differing water contents to examine the effect of high-salinity water on rock strength. These tests replicate the conditions encountered by the rock during mining operations and facilitate the assessment of the rock material's degradation behavior while in contact with saltwater. The mechanical properties of rocks are determined by systematically examining the variations in water saturation and the corresponding stress–strain behaviors. The research underscores the significance of comprehending these mechanical properties for anticipating mining-related issues. Subsequent to the testing phase, a comprehensive evaluation of the mechanical properties of the roof rock is conducted, resulting in the development of a damage constitutive model tailored to engineering rock masses. This model integrates the observed weakening effects, offering a more precise depiction of rock behavior under saltwater conditions, thereby improving our capacity to plan safer and more efficient underground mining operations in analogous high-salinity situations.