Experimental study on the sensitive neighboring area range of red sandstone under rheological disturbance effect

Deep rock masses are increasingly at risk of destabilization and disaster due to “strong disturbances” and “high geostress”. Conducting rheological disturbance effect theoretical research is a key part of controlling the stability of deep rock masses. Among these, the identification and analysis of the sensitive neighboring areas affected by rock rheological disturbance effects is an important component. This study, under different confining pressure conditions, subdivides the axial stress levels of red sandstone rheology, selecting stages of cumulative residual deformation development under rock rheological disturbance effects (attenuation stage, near constant speed stage, and acceleration stage). It combines the consistency correlation between the rheological disturbance effects and the dynamic response of the micro-pore structure of the rocks, analyzing from multiple perspectives the evolutionary characteristics of the sensitive neighboring areas affected by red sandstone rheological disturbance. The results show: ① Under different confining pressure conditions, the development stages of cumulative residual deformation in red sandstone rheological disturbance show characteristics similar to static rheology. With the increase of confining pressure, the response characteristics and rates of different stages change significantly, thereby affecting the stability and strength of the rock mass. ② Using the rheological disturbance sensitivity correlation coefficient of the rocks, the sensitive neighboring areas of red sandstone rheological disturbance are further divided into weakly sensitive and strongly sensitive areas, and it is pointed out that the weakly sensitive area should be considered a key stage in the stability protection of rheological rock masses. ③ By integrating the response analysis of macro and micro damage evolution characteristics under different confining pressure conditions, an increase in confining pressure leads to a contraction of the range of red sandstone rheological disturbance sensitive neighboring areas and a reduction in the weakly sensitive intervals, accelerating the transformation towards strongly sensitive characteristics. At the same time, with the increase of confining pressure, the failure development rate of red sandstone in the strong sensitive neighborhood also increases. This study, through a comprehensive analysis of the dynamic response of the micro-pore structure and macroscopic deformation of red sandstone under rheological disturbance effects, reveals from multiple perspectives the dynamic evolutionary characteristics of the sensitive neighboring areas affected by red sandstone rheological disturbance effects, providing a theoretical basis for the safe mining and stability assessment of deep rock masses.