During mining, rock failure and water infiltration induce variations in deformation, energy release, electrical conductivity, and water content. Their response laws underpin water-preserving mining optimization, environmental impact mitigation, and mining area sustainability, while facilitating the prediction of stratum instability and water migration. In this study, uniaxial compression experiments were conducted on sandstone with different water saturations, during which the responses of strain, acoustic emission energy, and electrical resistivity were monitored. The temporal characteristics of the rock’s multi-parameter responses were analyzed, and the influence of water content on precursor information of rock failure was revealed. Multi-parameter response equations for rocks under loading, incorporating the effect of water saturation, were established. A segmented variable-weight-integrated damage constitutive model for water-bearing rocks was developed based on the multi-parameter responses. The findings showed that the temporal characteristics of multi-parameter coupling responses can reflect the damage evolution and pore water migration during the instability and failure process of water-bearing rocks. As water saturation increased from 0% to 100%, the rock exhibited the following variations: peak stress decreased by 38.49%, strain at peak stress increased by 8.79%, elastic modulus decreased by 41.58%, cumulative acoustic emission energy drops by 93.23%, and initial electrical resistivity plummets by 98.02%. Compared with the theoretical stress–strain curves based on strain damage variables, cumulative acoustic emission energy damage variables, and electrical resistivity damage variables, the theoretical stress–strain curve based on the integrated damage variable shows better agreement with the measured curve, with the coefficient of determination exceeding 0.98. The research findings offer valuable insights into rock mass instability and groundwater migration, supporting water-preserving mining and sustainable mining area development.

To address the difficulty of determining the safe reserved thickness of the mining wall in the test block of the panel pillar at Tongkeng Mine, The stress of mining wall is comprehensively analyzed. Combined with numerical simulation method and field monitoring, the optimal wall thickness is determined. By differentiating each stress component, the mathematical equations governing the locations where extreme values of the stress components occur are derived, and the mathematical expressions for the extreme value positions of each stress component are further determined accordingly. Considering the geological characteristics and mining conditions of the experimental stope with panel pillars, the eastern mining wall of the test block is selected as the research object. A mining wall thickness range of 3 m to 8 m is designed, and the optimal safe reserved thickness of the mining wall is determined through numerical simulation. Based on the optimal mining wall retention thickness, stopping operations are carried out on the orebody of the experimental stope. Meanwhile, monitoring points are reasonably arranged from the upper-middle section to the middle of the mining wall, and real-time monitoring is performed on the stress variation data at each monitoring point during the entire stopping process of the test block. Theoretical analysis results show that the exact locations of the extreme values of each stress component can be accurately determined within the two-dimensional plane of the mining wall, among which the extreme value of the horizontal stress component appears at the midpoint of the mining wall thickness. Numerical simulation results indicate that both the stress and displacement of the mining wall exhibit a gradual decreasing trend with an increase in mining wall thickness. However, when the mining wall thickness exceeds 5 m, the reduction rate of stress and displacement slows down significantly, and the mining wall tends to become stable. Maintaining a mining wall thickness of 5 m in the experimental stope can generally ensure the safe recovery of the orebody. However, pronounced stress concentrations occur at the geometric corners of the mining wall, which result from stress retention caused by changes in the mining wall geometry. Meanwhile, the stress concentration in the mining wall is synchronized with that in the drilling galleries of the experimental stope, and varying degrees of failure occur in the drilling galleries at locations where stress concentration appears in the mining wall. Monitoring results show that the maximum stress borne by the drilling gallery is approximately 26 MPa, beyond which rock mass collapse and fragmentation are prone to occur.

Mudstone commonly acts as an aquiclude in underground mines, and its water-induced degradation can promote fracture propagation, pore-water migration, and water-inrush hazards. Due to its strong water sensitivity, water-bearing mudstone exhibits distinct mechanical degradation characteristics compared with water-bearing sandstone, requiring lithology-specific damage characterization. In this study, mudstone specimens with different water saturation levels were subjected to uniaxial compression, while mechanical, acoustic emission, and electrical responses were monitored simultaneously. The temporal evolution of these parameters was analysed to identify the influence of water saturation on failure precursors and to establish empirical relationships among the monitored responses. Based on these multi-parameter responses, a segmented variable-weight integrated damage constitutive model was developed to characterize the progressive failure process by considering the stage-dependent contributions of different damage indicators. The results show that increasing water saturation markedly weakens the mechanical and energy-storage capacities of mudstone: peak stress, elastic modulus, cumulative acoustic emission energy, and initial electrical resistivity decrease by 47.67%, 52.84%, 87.65%, and 97.59%, respectively, while peak strain increases by 18.88%. The integrated damage model reproduces the measured stress–strain curves more accurately than single-variable damage models, with a coefficient of determination exceeding 0.99. This study provides an experimental-scale framework for multi-parameter damage characterization of water-bearing mudstone and offers a basis for further investigation of aquiclude stability.