During the production of open-pit mines, the stability of slopes can be affected by various factors such as structural surfaces, production blasting vibrations, and mining areas. In this study, the researchers focused on the slope of the open-pit mine at Yinshan and employed UAV mapping technology to conduct an on-site geological engineering investigation. Information on the yield, trace length, spacing, and density of the structural surface of the south slope was obtained. The researchers also carried out vibration blasting tests in combination with the production blasting activities in the mine to determine the blasting vibration attenuation law and whether the blasting vibration speed met safety specifications. Additionally, numerical simulation methods were used to examine the influence of the mining area on the stability of the current slope and the designed excavation slope. The slope stability was evaluated using the limit equilibrium method, and the researchers separately discussed the influence of self-weight load and self-weight load plus blasting vibration force on the stability of the high slope of the open pit. The results showed the following: (1) The rock mass structural plane in the south slope of the mining area was mainly dominated by a medium-large dip structural plane, and three faults and joint fissures in the investigation area combined to form cutting and sliding surfaces in the rock mass that were prone to collapse and sliding. (2) The maximum blasting vibration speed met safety requirements. (3) There was no large range of plastic zone damage in the entire slope, and the overall stability of the slope was good. (4) The present slope was relatively stable when considering only self-weight stress and the blasting vibration force. However, there was a certain risk of instability in the design of the excavation slope.

We chose to study the bottom structure stress evolution law in the process of undercut area advancement via the block caving method, reveal the influence law of the undercut rate on the effect of the ore body caving process, and assess the floor stress evolution law in the process of the undercut area with a different undercut rate in order to guide the production of a natural disintegration method under horizontal ground stress and also provide some reference value for rock damage assessment. According to the actual engineering and physical parameters of the mine, a numerical simulation model was created by using finite discrete element software GPI-3D-FDEM, and the Neo–Hookean hyperelastic constitutive model was adopted for calculation purposes. The simulation process follows a backward bottoming approach and monitors and analyses the stress state of the substructure after each bottoming step. The indoor physical model is employed to conduct similar two–dimensional simulation experiments on similar materials, investigating the motion laws of overlying rock layers. The research findings indicate that as bottom blasting progresses, a gradual concentration of compressive stress occurs in the foundation structure ahead of the advancing line. If this stress surpasses the rock mass’s shear failure limit, ground pressure failure may ensue. During mineral extraction from the bottom, internal stress within the fractured fault zone significantly diminishes compared to adjacent rock and ore deposits.

The orebody and the surrounding rock of underground salt mine are generally divided into soft rock or extremely soft rock. In these mines, the strip room pillar method is primarily used. Continuous pillars with a certain width are left between every two mining strips. These pillars are used to provide support to the overlying surrounding rock. However, the stability of the pillars restricts the stope structural parameters of the mining method. Thus, it is important to first determine the main factors that affect pillar stability and analyze the influence level of these factors. Using a deep mining underground salt mine as an example, the characteristics of pillar instability and the pillar load are analyzed. The safety factor of the pillar refers to the ratio of pillar strength to pillar load, which can be used to quantitatively evaluate pillar stability. Based on the formula of pillar stress and the empirical formula of pillar strength, the formula of the pillar safety factor is deduced. Based on this formula, the primary factors affecting pillar stability are comprehensively analyzed. Moreover, the sensitivities of these factors are compared and analyzed based on the orthogonal range theory. According to the calculation results of the range, the factors influencing pillar stability in the underground salt mine are the mining depth and uniaxial compressive strength of ore, which are the most significant factors, followed by the height and width of pillars, and then the room width and unit weight of the overlying strata, which have relatively small influence. The safety factor of the pillar is positively correlated with the pillar width and uniaxial compressive strength but negatively correlated with the mining depth, pillar height, room width, and the unit weight of the overlying strata. The specific reasons of each factor affecting the safety coefficient are analyzed in detail. The changing trend of the pillar safety factor with various influencing factors can provide an important basis for the optimal design of stope structural parameters and the determination of support scheme.

To elucidate the mechanisms responsible for the low strength, pronounced variability, and long-term deformation of carnallitite, and to provide a basis for stope parameter design in deep potash mines, two carnallitite seams from a potash mine were investigated. Group C carnallitite and Group D halite-dominated rock salt were subjected to short-term compression tests and multiscale comparative analyses, while Groups A and B carnallitite specimens were tested under multistage creep loading. Particle Flow Code (PFC) simulations were conducted to evaluate the influence of particle size distribution. The results indicate the following: (1) The representative Group C specimens exhibited an average uniaxial compressive strength of 7.83 MPa, which was substantially lower than that of Group D. The acoustic emission (AE), scanning electron microscopy (SEM), and computed tomography (CT) analyses revealed greater heterogeneity in damage evolution and failure behavior, mainly associated with polymineralic composition, weak particle–matrix interfaces, local pores, and insufficient particle connectivity. (2) Particle-scale heterogeneity influenced the load-bearing capacity of carnallitite. In the PFC sensitivity analysis, narrowing the prescribed particle-size-distribution range from 0.4–8.0 mm to 4.0–4.0 mm at a mean particle size of 4.0 mm was associated with an increase in simulated strength from 7.82 to 10.40 MPa. Because quantitative contact-network descriptors were not extracted, the corresponding contact-network interpretation is treated as mechanistic rather than direct quantitative evidence. (3) The long-term uniaxial strengths of Groups A and B were estimated as 3.3 MPa and 4.8 MPa, respectively, using the adopted specific-failure-energy method. The modified Burgers model provided a good fit to the creep data within the tested stress levels, yielding coefficients of determination of 0.957 and 0.964 and root-mean-square error (RMSE) values of 0.0803 and 0.0552 percentage points. Based on the long-term strength constraints and the site-specific design assumptions adopted in this study, the calculated inter-room pillar widths were 6 m for Group A and 4 m for Group B. These findings provide insights into the multiscale damage mechanisms and long-term stability assessment of carnallitite stopes in deep potash mines.