Tailings pond is a place for storing tailings after beneficiation. The tailings sand is mainly composed of fine sand, fine sand and other non-cohesive soils, which are often in a saturated state. Therefore, under dynamic action, liquefaction is prone to occur and cause instability and damage to the tailings dam. This article takes the Gaowanqiu tailings pond in Shizhuyuan as the research background. Through on-site sampling, the basic physical properties and physical parameters of tail silt, Tail floury sand, and tail silty clay were tested. The dynamic parameters of tailings samples, including stress–strain relationship, axial strain characteristics, pore pressure characteristics, and dynamic strength characteristics, were tested using the DYNTTS dynamic triaxial testing system to investigate their dynamic characteristics under different confining pressures and dynamic stress ratios. Based on dynamic triaxial tests of different types of tailings samples, modified models for dynamic pore pressure and dynamic strength, as well as dynamic pore pressure and dynamic strain, were constructed. A modified model for dynamic pore water pressure of tailings materials during vibration was constructed by modifying the Seed model, and a dynamic pore pressure dynamic strain relationship model suitable for tailings materials was constructed by linearly expressing the relationship curve between pore pressure and strain of tailings materials. The model is in good agreement with the experimental results and can accurately predict the relationship between dynamic pore pressure and dynamic strain of tailings materials.

PCBN tools are widely used in the machining of ferrous metals. Tool edge preparation is a crucial procedure in the tool preparation process that directly affects tool performance. In this paper, tool chamfer grinding and edge blunting were conducted on the PCBN tool to investigate the effect of material microstructures. In tool chamfer grinding, the PCBN tool with larger particles exhibits a larger chamfer width error and roughness than that of smaller particles, and the PCBN tool with higher Al content exhibits a larger chamfer width error and roughness than that with lower Al content. The optimal tool chamfer grinding speed is 24 m/s for the PCBN tool with larger particles, and 27 m/s for smaller particles. The optimal feed rate is 70 mm/min for both PCBN materials. In edge blunting, PCBN tools with larger particles or lower Al content are more difficult to passivate, and the optimal blunting time is about 30 s for an edge radius of 30 μm. The PCBN tools were prepared using the obtained machining parameters and used in the turning of brake pads. It is found that the PCBN tool with smaller particles exhibits longer life than that of larger particles. Although it exhibits the same wear characteristics, the tool life of the PCBN tool with lower Al content is longer than that of the tool with higher Al content.

ABSTRACT: Tailings dams, particularly those constructed via the centerline method, are vulnerable to rainfall-induced erosion and infiltration. This study develops a novel hybrid mortar combining alkali-activated materials (AAM) from industrial waste with enzyme-induced carbonate precipitation (EICP) using a soybean urease solution, and completely replaces natural sand with copper tailings. The workability, strength, permeability, and microstructure of AAM and EICP-AAM mortars were evaluated. Results show that both mortars achieved a 28-day unconfined compressive strength exceeding 300 kPa. The EICP-AAM mortar exhibited a 15% higher early strength (3 and 7 days) than the AAM mortar. Microstructural analysis revealed a composite of calcium carbonate precipitates and alkali-activated gels in the EICP-AAM system, explaining its enhanced early performance. Permeability coefficients of both mortars after 14 days of curing were reduced by over 90% compared to raw tailings, with the EICP-AAM mortar showing an 8% lower permeability at 7 days due to synergistic sealing. Practical zoned spraying and collaborative mitigation strategies are proposed for dam surface reinforcement. This study provides a low-carbon, waste-utilizing material and elucidates the synergistic mechanisms for enhancing the long-term stability of tailings dams.

The permeability and compressibility of a saturated tailing materials are important parameters in the field of mining safety and geotechnical engineering. The geometric characteristics of a porous medium are key factors in the prediction of its permeability and compressibility. In this paper, the compression and hydraulic characterizes of different gradation tailings through high-stress permeability compression tests were herein investigated. Then, the relationship between the geometric parameters and the high-stress permeability and compressibility of tailings is established. Based on PFC numerical simulation, the non-spherical cluster particles with different fractal dimension and other geometric parameters were constructed, and the compression simulations considering particle breakage were carried out. Using tests and simulations analysis, the influence degree on the compressibility of tailings is as follows: Ultrafine content (F-c) > Roundness (R-c) > Sphericity (S-k) > Fractal dimension (F-d). Numerical simulation proves that particle breakage and water film are closely related to particle shape, and the prediction formula proposed has a wider scope of application on high-stress permeability and compressibility of saturated tailings materials.

Tailings dams are loose due to sequential accumulation and prone to failure under high-intensity rainfall. Particle gradation determines the mechanical, seepage, and rheological properties of tailings and is a key factor in dam scouring damage, while rainfall-induced gully progression mechanisms for different gradations remain underexplored. This study adopted laboratory physical model tests combined with Three-dimensional Light Detection and Ranging (3D LiDAR) and high-definition photography to dynamically capture 3D surface evolution of tailings dams with three gradation types. Quantitative analysis revealed the spatiotemporal evolution of scouring depth, deposition height, and surface shape. Results show scouring damage initiates at high-energy zones near dam toes and propagates upward through four phases, including embryonic gully formation, gully progression, stable gully growth, and collapse deformation. Scouring and deposition interactions govern gully progression through scouring dominance, deposition regulation, and dynamic equilibrium, via particle-selective transport and self-inhibition deposition. An optimised time-dependent gully depth predictive model incorporating effective rainfall intensity, gradation parameters, and permeability quantifies their synergistic effects on scouring kinetics with 95% accuracy. This study reveals gradation-dependent gully evolution in tailings dams under high-intensity rainfall and develops a predictive model to quantify these processes, providing a theoretical basis and quantitative tool for forecasting rainfall-induced dam failure.

Copper tailings with a high fines content commonly exhibit low strength, poor drainage-related hydraulic behavior, and environmental risks. In this study, a waste-derived geopolymer binder (WGB) was used to stabilize copper tailings. The reaction mechanism was examined by X-ray diffraction and X-ray photoelectron spectroscopy, while the engineering performance was evaluated through unconfined compressive strength (UCS), nuclear magnetic resonance spectroscopy, hydraulic conductivity, and leaching tests. The 28-d UCS of the WGB-stabilized tailings reached 11.75 MPa, exceeding that of the cement-stabilized counterpart (8.5 MPa). The reaction products were dominated by hydrate-related gels and sulfate/aluminate hydrate-related products, which progressively bonded tailings particles and formed a more developed cemented matrix. Fine-grained tailings showed greater reactivity than the coarse fraction and participated in the evolution of the cemented structure under alkaline activation. Pore characterization showed that the fractions of micropores and capillary pores decreased from 14.2% to 12.96% and from 41.35% to 36.76%, respectively, while the relative macropore proportion increased to 50.28%. This pore redistribution was accompanied by an increase in hydraulic conductivity from 4.04 × 10−5 to 5.41 × 10−4 cm/s at 28 d and 5 wt% WGB dosage. The leaching concentrations of Ni, Zn, and Pb decreased by 97.29%, 99.98%, and 94.4%, respectively. A preliminary raw-material cost comparison showed that WGB (18.88 USD/t) was less costly than a representative alkali-activated stabilizer (63.62 USD/t) and ordinary Portland cement (OPC) (39.92 USD/t). These results demonstrate that WGB stabilization upgrades copper tailings through coupled fines participation, interparticle cementation, pore-network reconstruction, drainage enhancement, and contaminant immobilization, rather than through strength gain alone.

The effect of the intermediate principal stress ratio (b) on the mechanical behavior of a tailings material was investigated via the discrete element method to simulate true triaxial tests. Particle breakage satisfied the octahedral shear stress breakage criterion, and the breakage process employed both the bonded-particle method and the fragment substitution method. The macroscopic behavior of the tailings revealed that when b < 0.75, the shear stress ratio is sensitive to b, and when b > 0.75, the effect of b on the shear behavior is minimal. The strain softening or hardening behavior of the sample is determined by confining pressure, with b altering only the degree of this behavior. Conventional triaxial tests underestimate tailings strength in true triaxial stress states. A new strength criterion considering b, based on the power function Mohr-Coulomb strength criterion, is proposed. The evolution of micromechanical parameters such as the fabric, contact characteristics, and anisotropy coefficients was investigated. The results indicate that the resistance provided by nonfailed contacts is the main source of the specimen shear strength. Sliding failure is the primary cause of the reduction in the specimen shear strength. This study elucidates the effects of stress paths on the mechanical behavior of tailings from both microscopic and macroscopic perspectives.

As mining activities result in increased volumes of tailings storage and extended storage durations, technologies for tailings solidification, backfilling, and in-situ reinforcement face challenges posed by acid mine drainage. This study investigates the mechanism of sulfuric acid attack on AAMs used for solidifying tailings, focusing on changes in hydration products and microstructural evolution across different curing stages. Short-term (3-day) acid immersion tests revealed that AAM paste specimens maintained structural integrity with a slight strength increase, whereas AAM-solidified tailings experienced strength reduction due to the dissolution of tailings constituents. Microscopic analysis indicated that early-stage hydration products (C-S-H, C-A-H, and CH) were susceptible to acid-induced degradation, leading to pore formation. In later stages, aluminum incorporation transformed C-S-H into more stable C-(A)-S-H, forming reinforced networks that enhanced acid resistance. The acidic environment promoted gypsum crystallization via CH hydrolysis, filling macropores and densifying the microstructure temporarily. However, long-term exposure risks gypsum overgrowth, causing damage to the gel network and microstructural integrity, which requires further research. Ultimately, this work provides critical insights for promoting sustainable mining practices, improving tailings management, and strengthening environmental safeguards.

This study investigates the dynamic mechanical properties and failure characteristics of jointed gypsum under impact loading. Uniaxial dynamic tests were conducted on specimens with different joint angles to analyze their stress–strain behavior, energy dissipation, and failure modes across varying strain rates. At low strain rates, unloading rebound occurs, producing a closed stress–strain curve. As strain rate increases, deformation accumulates and the curve transitions to an open type due to irreversible damage. Intact, 0°, and 90° specimens mainly exhibit axial splitting, whereas 30°, 45°, and 60° specimens show mixed modes dominated by joint-plane sliding. Higher strain rates intensify crack activation, leading to crushing failure. Energy evolution proceeds through four stages: elastic storage, cracking initiation, continuous absorption, and splitting failure with or without energy release. Under identical impact pressure, intact specimens display the lowest reflection and highest transmission coefficients. Reflection peaks at 45°–60° and then decreases, while transmission shows the opposite trend. With increasing incident energy, reflected and absorbed energies grow linearly, whereas transmitted energy first rises then declines, especially at 30°–60°. Dynamic compressive strength and elastic modulus exhibit a U-shaped relation with joint angle, reaching minima at 45°. Both parameters increase with strain rate, with yield strength showing exponential growth and a marked rise beyond 65 s⁻1. These findings elucidate the coupled effects of joint angle and strain rate on gypsum behavior, providing theoretical guidance for safe deep gypsum mining.

The seismic vulnerability of tailings with various types necessitates improved liquefaction resistance prediction. Cyclic triaxial tests on tailings revealed two axial strain patterns (stable-rapid with shear expansion, and rapid trends) and four-stage EPWP generation via the BiDoseResp model. Equivalent void ratio (e(g)*) non-monotonically correlates with fines content (F-C), defining three liquefaction phases: coarse-grained dominant (F-C < threshold fine content (F-Cth)), coarse-fine-grained transitional behavior (F-Cth < F-C < 0.65), and fine-grained dominant (F-C > 0.65). Peak resistance at F-C = 0.65 underscores optimal coarse-fine balance. The BiDoseResp model integrates e(g)*, cyclic stress ratio (CSR), and confining pressure (sigma(3)) for robust prediction.

The PCBN tools are the most suitable tool to machine the cast iron materials, which is the main material to produce brake discs in the various vehicles. The cutting simulation is the most cost-effective and widely used method to obtain the optimal tool geometric design. The constitutive model of workpiece material is the foundation of the cutting simulation for tool design. In this paper, the constitutive models of cast iron material are tested with various test methods, include the split Hopkinson pressure bar test, the thermophysical test and turning experiments. Based on the constitutive model of cast iron, the cutting simulation model was established and verified, the simulation error is within an acceptable range of less than 10.80 %. By the application of the cutting simulation, the optimal cutting edge geometric design of PCBN tool for machining of cast iron was obtained, the cutting edge radius of 30 mu m, the chamfer width of 10 mu m and chamfer angle of 15 degrees. The research results can offer an important guideline to tool design for machining of cast iron materials.

Gold mine tailings (GMTs) pose significant environmental challenges, and while alkali-activated materials (AAMs) have been widely used as sustainable alternatives to Portland cement for stabilizing geotechnical materials, further research is needed to optimize their composition and performance, particularly by incorporating traditional industrial waste residues to develop composite alkali-activated materials (CAAMs) with improved mechanical properties and reduced environmental impact. Different CAAMs admixtures (i.e., 0%, 3%, 5%, and 8%) and gold mine tailings were prepared, and the samples were solidified under saturated water and no air. In order to investigate the mechanical characteristics of CAAMs-stabilized GMTs, laboratory direct shear tests were carried out on samples after curing them for 3, 7, 14, and 28 days, respectively. The test results showed that with the extension of curing time, the brittleness of the samples increased, and the stress–displacement curves for all the cured specimens changed from plateau type to peak type. Both curing time and CAAMs content are conducive to improving the shear strength of CAAMs-stabilized GMTs samples, but the increase rate decreased as the vertical confining stress increased. Furthermore, the influence of CAAMs content on shear strength increment was larger than that of curing periods. The exponential growth model could well describe the change of shear strength with the curing periods under different vertical stresses. The paper can provide theoretical support for the application of CAAMs to enhance the stability of tailings dams.

This study focuses on the safety characteristics of the deep gypsum mining process, considering the stress and joint characteristics of the pillar rock mass. The split Hopkinson pressure bar (SHPB) test system and finite element method (FEM) software ANSYS were used to investigate the dynamic mechanical response of intact gypsum rock and 45° jointed specimens under one-dimensional coupled dynamic and static loads with varying axial compression ratios (ACR) and impact pressures. The effects of ACR and strain rate on the strength, failure mode, energy transfer, and dissipation mechanisms of the gypsum rock were analysed. The results show that, under constant impact pressure, the dynamic uniaxial compressive strength (DUCS) initially increases and then decreases as ACR increases. The DUCS of the intact specimen peaks at an ACR of approximately 0.5, while the maximum DUCS of the 45° jointed specimen occurs at an ACR of around 0.4. Under low-intensity axial preload, the closure of microcracks within the rock increases DUCS, but as axial load increases, the initiation and expansion of secondary cracks reduce the DUCS. Under one-dimensional coupled dynamic and static loading, the failure mode of the specimen differs significantly from that under uniaxial dynamic impact loading. The intact specimen primarily experiences compression and shear failure, with some specimens exhibiting tensile failure. In contrast, the specimen with 45° joints predominantly exhibits shear failure, forming a macroscopic fracture surface along the crack, along with the extension of wing and anti-wing cracks. At high ACR, the energy absorption (EAb) capacity of the specimen is reduced, and the rock is prone to peeling and detaching along the outer compression and shear surfaces, leading to a rock burst. The DUCS of gypsum rock specimens increases with the strain rate (ε̇). Based on experimental data, the exponential relationship between DUCS and ε̇ is fitted, revealing the variation of DUCS in gypsum rock under different ACR and ε̇ loading. Analyzing the energy reflection coefficient (ERe/EIn), energy transmission coefficient (ETr/EIn), and energy absorption coefficient (EAb/EIn) reveals the energy conversion characteristics of gypsum rock specimens under varying axial preloads. At low ACR, the original cracks in the rock close, enhancing energy absorption capacity. At high ACR, especially when the axial static load approaches the elastic energy storage limit of the specimen, the rock is prone to releasing stored elastic energy during dynamic disturbance, leading to a rock burst. These results provide valuable insights into deep rock dynamics and offer a scientific basis for the mining safety and disaster prevention of deep gypsum mines.

ObjectiveLimitations of predefined physics interfaces in handling nonstandard models, complex boundary conditions, and tailored discretizations motivate a weak-form strategy in COMSOL Multiphysics (COMSOL) that directly expresses governing equations, boundary terms, and stabilization choices. A general framework is established to formulate and solve custom weak-form partial differential equations (PDEs), enhancing control over variational statements, interface fluxes, and discretization. The strategy is evaluated on two representative classes: nonlinear diffusion governed by the Porous Medium Equation (PME) and plane-strain linear elasticity in a plate with a geometric discontinuity.MethodsThe approach is grounded in the variational principle, generalized derivatives, and weighted residuals within Sobolev spaces. Natural boundary conditions are incorporated via surface terms; test and trial spaces are selected for stable discretization. COMSOL's Weak Form PDE interface is used to define residuals, test functions, and fluxes symbolically, avoiding dependence on built-in physics modules and enabling tailored discretizations with explicit nonlinear operators. For nonlinear diffusion, the PME is investigated in one and two dimensions. In 1D, a conservative state variable is advanced in time with diffusivity depending on a power m>1. Initial and boundary conditions admit compactly supported solutions, benchmarking preservation of nonnegativity and the capture of sharp moving fronts without spurious oscillations. Representative m values probe sensitivity to nonlinearity, and mesh refinement examines monotonic convergence and suppression of oscillations near compact supports. In 2D on a unit square, zero-flux boundaries and smooth, centered, radially symmetric initial data are imposed to observe diffusion dynamics and approach to equilibrium. A relative deviation metric is used qualitatively to assess decay toward the spatial mean. For linear elasticity, a plane-strain square plate with a concentric circular void is modeled. The left boundary is fully constrained; the right boundary is prescribed a uniform horizontal displacement; the top and bottom boundaries are traction-free. The material is isotropic linear elastic. Displacements serve as primary unknowns; strains derive from displacement gradients; stresses follow Hooke's law. The weak-form implementation computes displacement fields, normal and shear stresses, and von Mises equivalent stress to analyze deformation and stress concentrations driven by the cavity and boundary restraints. Across both classes, evaluation focuses on numerical stability, solution smoothness, mesh dependence, and consistency with established physical behavior. Emphasis is placed on reducing artificial oscillations, preserving qualitative invariants for the PME (nonnegativity and compact support), and reproducing theoretically consistent stress patterns for perforated plates under displacement boundary conditions.Results and Discussions The WF implementation accurately reproduced hallmark properties of the PME. In one dimension, compact support was maintained throughout the simulation horizon, and fronts propagated with finite speed. As m increased from 2 to 8, the support narrowed and front propagation decelerated, leading to more localized profiles—consistent with theoretical expectations for nonlinear diffusion. Mesh refinement from N = 15 to N=100 yielded monotonically smoother internal profiles and visibly reduced oscillations near moving fronts, indicating strong numerical stability of the weak-form discretization even on comparatively coarse meshes. The approach provided improved control over residual definition and test function pairing, which facilitated stable handling of nonlinear fluxes and sharp interfaces. In two dimensions, the WF model produced diffusion patterns that respected nonnegativity, symmetry, and boundary conditions. The relative deviation metric demonstrated consistent temporal decay toward equilibrium for all tested m, while the decay rate depended on the nonlinearity strength. Smaller m values exhibited faster approach to equilibrium; larger m values showed initially noticeable diffusion followed by progressive slowdown as gradients flattened, reflecting the diminishing effective diffusivity of the PME at low state values. Representative values of the deviation metric at a fixed time confirmed these trends and provided a quantitative basis for comparing equilibration speeds across parameter settings. For the elastic plate with a central cavity, the deformation field showed rightward elongation as expected under imposed boundary displacement, with the largest displacements located near the middle of the loaded edge. Normal stress σxx was broadly distributed with slight increase toward the right boundary. Shear stress τxy and σyy remained comparatively small in accordance with the loading configuration. Von Mises equivalent stress reached maxima near the upper-left and lower-left corners of the internal cutout and at constrained corners, consistent with stress concentration phenomena in perforated plates subject to in-plane loading. These distributions were aligned with classical elasticity predictions, supporting the correctness and reliability of the WF discretization. Taken together, the findings indicated that custom weak-form modeling in COMSOL retained key physical invariants, reduced spurious oscillations in nonlinear diffusion, and recovered theoretically consistent stress concentration patterns in elasticity. By bypassing the constraints of prepackaged physics interfaces, the approach enabled direct expression of governing equations, boundary terms, and stabilization choices, thereby improving flexibility and facilitating targeted accuracy and convergence gains. The observed behavior suggests favorable numerical conditioning and robustness for problems featuring nonlinearity, complex boundary integrals, or bespoke constitutive treatment.ConclusionsDirect weak-form formulation within COMSOL offers a practical and accurate route for custom PDE modeling in geotechnical contexts. For the PME, solutions preserve compact support, capture finite-speed fronts without pronounced oscillations, and converge smoothly under mesh refinement. For linear elasticity with a cavity, displacement and stress fields follow theoretical expectations, including cavity-corner stress concentrations and constrained-region effects. These outcomes affirm the applicability of weak-form discretization to nonlinear diffusion and elastic deformation and highlight enhanced modeling flexibility for complex boundaries and tailored numerics. The approach yields stable, convergent solutions with reduced artifacts and provides a foundation for extensions to multiphysics couplings and advanced constitutive behavior.

The centrifuge experiment was conducted to investigate the impact of weak interlayer reservoir bank slope water level rise on slope stability. The analysis of the experimental data revealed that the collapse of the reservoir bank slope was primarily caused by the rapid rise in water level in the reservoir, leading to increased infiltration along the slope. This process resulted in the weakening of the interlayer strength and the reduction in the strength of the reservoir bank slope soil body. Consequently, transverse cracks began to form at the foot of the slope, which expanded and eventually led to segmental slope collapse. Concurrently, the correlation between soil water content and physical strength index was determined through conducting direct shear experiments on test soils with varying water contents. This correlation was integrated into a numerical model to predict the sliding surface of the slope soil. The numerical model was validated using centrifuge model experiments. The outcomes of these experiments demonstrated that the circular sliding surface generated by the calculations was largely consistent with that observed in centrifugal experiments. Ultimately, a detailed finite element model was developed to simulate the relationship between the safety factor of the bank slope and the height of water level rise, on the basis of the physical model. This study can provide a scientific reference for the study of the collapse mechanism of the bank slope due to the rise of water level.

PCBN is the most suitable tool material for machining of ferrous materials, the double-sided grinding is the necessary operation in preparation of PCBN tools. In this paper, surface roughness and material removal rate in double-sided grinding of PCBN materials with different grain sizes and binder phases are studied. Based on the results, the PCBN material with low Al content achieves lower surface roughness and higher material removal rate. The binder phase with low Al content exhibits greater binding strength and is more difficult to remove, it also reduces the possibility of the spalling pit formation on the machined surface. The grain size of PCBN has a greater influence on surface roughness and material removal rate. The PCBN material with small grain size presents superior surface quality and material removal rate, and is easier to remove. The optimal double-sided grinding parameters are obtained for PCBN tools, the upper abrasive disc speed of 20 rpm, the lower abrasive disc speed of 30 rpm and the inner pin ring speed of 30 rpm, the grinding pressure of 300 kPa. The results can guide the actual preparation process for PCBN tools.

The effects of confining pressure and particle breakage on the mechanical behavior of tailings were investigated using the discrete-element method to simulate conventional triaxial tests. The particle breakage was simulated using the octahedral shear stress breakage criterion and 14 Apollonian fragments replacement method. The macroscopic behavior of tailings revealed that the peak shear stress ratio is sensitive to confining pressure and the critical shear stress ratio is less sensitive to particle breakage. Confining pressure and particle breakage affect shear expansion, leading to changes in shear damage patterns. The quantitative study shows that particle breakage is the main factor influencing the nonlinear variation of the tailing strength. However, the influence proportion of particle breakage is gradually decreasing with the increase in the confining pressure. Microscopic analysis reveals a positive correlation between the overall anisotropy and the shear stress ratio, with the anisotropy of the normal contact force distribution contributing the most. The variation of the overall anisotropy is caused by the variation of the contact state, in which the sliding contact state is the main influencing factor.

With the continuous increase in mining activities, effective tailings management has become a critical concern in geotechnical and environmental engineering. This study systematically investigates the microstructural characteristics and 3D reconstruction behavior of copper tailings with different particle sizes using X-ray computed tomography (micro-CT), digital image processing, and 3D modeling techniques. Two particle size groups (fine: 0.075-0.15 mm; coarse: 0.15-0.3 mm) were analyzed to quantify differences in particle morphology, pore structure, and orientation anisotropy. Binary images and reconstructed models revealed that coarse particles tend to have more irregular and angular shapes, while fine particles exhibit more complex pore networks with higher fractal dimensions. The apparent porosity derived from CT data was consistently lower than laboratory measurements, likely due to internal agglomeration effects. Orientation analysis indicated that particle alignment and anisotropy vary systematically with section angle relative to the principal stress direction. These findings offer new insights into the particle-scale mechanisms affecting the packing, porosity, and anisotropy of tailings, providing a scientific basis for enhancing the structural evaluation and sustainable management of tailings storage facilities.

Adopting an appropriate method to analyze the spatial evolution process of tailings flow after tailings dam failure can provide a rational assessment of the inundation range and evaluate the subsequent disaster. Simultaneously, it can offer a foundation for tailings pond construction and safety management. This paper, focusing on a specific iron mine in Xiagao, Guangdong, establishes a three-dimensional simulation of the tailings pond based on the design drawings of the raised tailings pond. Utilizing the depth integral method as the theoretical basis, this research references parameter values obtained through model experiments for numerical simulation. Through the numerical simulation method, the study simulates the disaster range, flow, and spatial state of the tailings flow after a dam break. The tailings flow velocity and the depth of the flow in the affected areas are derived, demonstrating the disasters resulting from dam failure. Moreover, the feasibility of raising the tailings dam is evaluated. The assessment extends to the damage risk of tailings dam failure to critical downstream facilities and provides disaster prevention and control suggestions for high-risk situations. This study ultimately offers technical support for the prevention and control of tailings dam failure accidents and the advancement of mine safety production.

To investigate changes in stope stability and cemented tailings backfill (CTB) strength during deep metal mine mining using the filling method in a high-temperature environment, this study analyzed the temperature and mechanical characteristics of the stope via numerical simulations. The optimal CTB mix ratio at different mining depths was determined, and the corresponding safety control measures for deep metal mine filling mining were proposed. Results show that the coupled effect of the temperature field and hydration heat release during deep filling mining complicate the stope environment. Owing to the difficulty in heat dissipation in the middle of the bulk CTB in the stope, the internal temperature of the CTB increases significantly within a short duration. Moreover, the rapid heat conduction around the CTB caused by its direct contact with the surrounding rock causes the temperature field to distribute from the center to the periphery. Throughout the sublevel mining process, the CTB temperature field exhibits the following change pattern: stable-a rapidly increasing-a slowly decreasing-a rapidly increasing-a slowly decreasing to stable-a slowly increasing-a slowly decreasing to stable. A comparison of test results obtained from pillar mining simulations show that the coupled temperature-stress model exhibits greater stability and safety than the single mechanical model. The CTB provides better support under the coupling effect, thus enhancing its mechanical properties under high temperature. A safety factor is introduced for the quantitative analysis of slope stability. The optimal CTB mix ratio at different mining depths is determined via safety factor iteration and economic comparison analysis. Subsequently, a reasonable temperature control scheme was designed, which offers insights into high-efficiency mining while ensuring CTB stability under high temperature.