Research on the Failure Mechanisms and Strength Characteristics of Deeply Buried Mudstone under the Interaction of Water and Stress

Mudstone is a widely occurring type of rock in deep mining, and it crucial to understand its failure mechanisms strength characteristics under the interaction water high stress ensure stability deeply buried engineered mudstone. In this study, composition structure mudstone were obtained, triaxial tests conducted on five different contents four confining pressures using servo press. The variation rules for peak residual applicability criteria was analyzed through fitting. results showed that both decreased linearly with increasing content, decreasing more rapidly. Both increased pressure, decrease primarily due cohesion, cohesion from 8.40 MPa 0.94 1.75 0.82 MPa. internal friction angle did not change much, 41.57° 37.29° post-peak 32.35° 33.28°. For dry low-water-content mudstone, conformed Mohr–Coulomb criterion, while higher Hoek–Brown criterion. Under low medium pressures, played dominant role damage pattern fractures produced by initial perimeter guiding