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

Abstract The mechanical properties of the surrounding rock at the island working face have 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 circumstances, with particular emphasis on sandstone samples typically found in these settings. A series of dynamic loading tests are undertaken on sandstone specimens with differing water contents to examine the effect of high-salinity water on rock strength. These tests replicate the circumstances encountered by the rock during mining operations and facilitate the assessment of the rock material's degradation behavior while in contact with saltwater. Through systematic analysis of the test findings, accounting for fluctuations in water saturation levels and the corresponding stress-strain responses, we may extract essential insights about the mechanical properties of the roof rock. The research underscores the significance of comprehending these mechanical properties to anticipate problems in mining. 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 specifically designed for the engineering rock mass. This model integrates the observed weakening events, 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.