Analysis method for sedimentation and consolidation behavior of laminated tailings based on mining method

Abstract

The present application relates to the technical field of tailings analysis, and particularly relates to a layered tailings deposition-consolidation behavior analysis method based on a tailing discharge mode, comprising: constructing a physical model for tailings deposition-consolidation behavior and mechanism analysis; constructing tailings body consolidation control equations, continuity equations, boundary conditions and consolidation equations; constructing a tailings deposition-consolidation coupling numerical model, embedding an inbuilt module of finite element analysis software; constructing a tailings deposition-consolidation analysis model considering self-weight effect and material spatial variability, obtaining superstatic pore water pressure distribution and consolidation ratio evolution law through numerical simulation by applying dynamic variable load of continuous accumulation, cyclic accumulation or intermittent accumulation, and controlling boundary drainage conditions, and analyzing the influence mechanism of tailings deposition-consolidation behavior accordingly. The present application comprehensively considers self-weight and heterogeneity, accurately reveals the layered tailings deposition-consolidation mechanism based on the tailing discharge mode, and improves the prediction accuracy of layered tailings deposition-consolidation behavior.

Description

Technical Field

[0001] This invention relates to the field of tailings analysis technology, and in particular to a method for analyzing the sedimentation-consolidation behavior of layered tailings based on the ore discharge method. Background Technology

[0002] Tailings dams, as an indispensable and crucial facility in metal mining production, play a critical role in storing tailings. Due to their unique physical and engineering characteristics, tailings dams essentially constitute artificial structures with high potential energy risks. Their stability not only directly affects mine safety but also has a profound impact on the surrounding ecological environment. In recent years, with the continuous increase in the intensity of mineral resource development and the continuous optimization of mineral processing technology, the discharge of fine-grained tailings has increased significantly. These tailings materials typically possess engineering characteristics such as low shear strength, low permeability coefficient, and slow consolidation rate. This leads to common engineering problems during tailings dam operation, such as the accumulation of excess pore water pressure and lagging development of sedimentary layer strength, seriously threatening the long-term stability of the dam body. Traditional consolidation theories are mainly based on the Terzaghi one-dimensional consolidation theory framework and the assumption of homogeneous materials, making it difficult to accurately characterize the influence mechanism of dynamic operating parameters on the consolidation characteristics of tailings during actual tailings accumulation. Therefore, predicting the sedimentation-consolidation law of tailings under the coupling of hydraulic separation effect and self-weight is of great theoretical value and engineering guiding significance for improving the safety design level of tailings dams and optimizing operation and management.

[0003] While some progress has been made in this area, most studies have considered the impact of key operating parameters such as tailings accumulation interval and accumulation rate. In reality, for tailings dams, the tailings accumulation method is a crucial factor influencing the tailings deposition-consolidation characteristics and even the stability of the dam. Therefore, establishing a mathematical model for tailings deposition-consolidation that couples different tailings accumulation methods has significant theoretical innovation value and engineering practical implications.

[0004] Chinese invention patent application CN119150538A discloses a method for analyzing the anti-sliding stability of underconsolidated saturated fine-grained tailings dams. This method involves loading the tailings dam in stages from bottom to top, maintaining a constant consolidation coefficient, and assuming water seepage is primarily vertical. It modifies Terzaghi's one-dimensional seepage consolidation theory by incorporating the loading and consolidation characteristics of saturated fine-grained tailings dams. It assumes a constant consolidation coefficient during seepage consolidation, vertical or horizontal water seepage, and uniform loading in stages. The degree of consolidation is calculated for each stage of loading and weighted averaged according to the loading amount to derive the relationship curve between the degree of consolidation and burial depth. However, this method cannot accurately predict the dynamics of excess pore water pressure dissipation and the development law of the degree of consolidation during the deposition and consolidation process, requiring further improvement. Summary of the Invention

[0005] The purpose of this invention is to address the shortcomings of the aforementioned background technology by providing a solution that can simulate actual tailings accumulation conditions and predict the dynamics of excess pore water pressure dissipation and the development law of consolidation degree during the deposition and consolidation process.

[0006] To achieve the above objectives, this invention provides a method for analyzing the sedimentation and consolidation behavior of layered tailings based on the ore discharge method, comprising the following steps: Construct a physical model for the analysis of tailings deposition-consolidation behavior and mechanism; Construct the consolidation control equation, continuity equation, boundary conditions, and consolidation equation for the tailings body; A numerical model of tailings deposition-consolidation coupling was constructed and embedded into a built-in module of the finite element analysis software; A tailings deposition-consolidation analysis model considering self-weight effect and material spatial variability was constructed. By applying dynamic variable loads of continuous, cyclic, or intermittent stacking and controlling boundary drainage conditions, numerical simulation was used to obtain the distribution of excess pore water pressure and the evolution of consolidation ratio. Based on this, the influence mechanism of stacking mode, stacking rate, stacking period, and drainage boundary on tailings deposition-consolidation behavior was analyzed.

[0007] Furthermore, the physical model for analyzing the tailings deposition-consolidation behavior and mechanism consists of a homogeneous layer with heterogeneous dry mechanical parameters and a permeability coefficient of... The top is a suspension zone, set as an impermeable boundary, and the bottom is a horizontal drain pipe, set as a semi-permeable boundary. The time-varying load rate is defined based on the daily tailings accumulation thickness. ,in Set tailings accumulation load to saturate specific gravity. It is dynamically controlled by the tailings accumulation method, and represents the overload pressure formed by the continuous accumulation of newly added tailings above the consolidation zone.

[0008] Furthermore, the formula for calculating the tailings accumulation load is as follows: .

[0009] Furthermore, the governing equations for tailings consolidation and the continuity equation are set as follows:

[0010]

[0011]

[0012] in, For the first Pore ​​water pressure in the layer Number the tailings layer. This represents the total number of tailings layers. The consolidation coefficient is . For depth coordinates, For time, For the first The thickness of the layer.

[0013] Furthermore, when setting boundary conditions, the boundary conditions of the horizontal drainage pipe are set as semi-permeable boundaries, and the upper boundary of the horizontal drainage pipe is represented as:

[0014] The lower boundary is represented as:

[0015] in, and These are the semi-permeability coefficients of the upper and lower boundaries, respectively. This is the total thickness.

[0016] Furthermore, when setting the consolidation equation, the expression for the initial condition considering self-weight is:

[0017] in, For the first Effective density of tailings. For the first The effective density of tailings below the tailings layer, and the first The tailings of the layers are all located in the first layer. Below the tailings layer; Introducing average degree of consolidation The expression is: .

[0018] Furthermore, the governing equations of the constructed tailings sedimentation-consolidation coupled numerical model are expressed as follows:

[0019] in, For quality coefficient, Where is the diffusion coefficient. The absorption coefficient is... The hindrance coefficient is... For source terms, For conservative flux convection coefficient, To conserve flux source terms, The convection coefficient; Substituting the tailings consolidation control equation and the continuity equation into the model control equation, we obtain:

[0020] in, It is the density of water.

[0021] Furthermore, the upper and lower boundary equations of the Robin boundary conditions corresponding to the flux / source conditions are expressed as follows:

[0022]

[0023] in, For boundary flux, , These are the boundary absorbing terms for the bottom and top boundaries, respectively; Substituting the upper and lower boundary equations of the horizontal drainage pipe into the upper and lower boundary equations of the Robin boundary conditions, we get: .

[0024] Furthermore, a tailings deposition-consolidation analysis model considering self-weight effects and material spatial variability is constructed. By applying dynamic variable loads of continuous, cyclic, or intermittent stacking and controlling boundary drainage conditions, numerical simulations are used to obtain the distribution of excess pore water pressure and the evolution of consolidation ratio. Based on this, the influence mechanisms of stacking mode, stacking rate, stacking period, and drainage boundary on tailings deposition-consolidation behavior are analyzed, including: A tailings sedimentation-consolidation analysis model was constructed, which divided the tailings layers into several equal-thickness layers along the depth direction. The top boundary of the model was set as an impermeable boundary and the bottom boundary as a semi-permeable boundary. Multiple tailings accumulation conditions are set up, and the tailings accumulation methods corresponding to each tailings accumulation condition include continuous accumulation, cyclic accumulation and intermittent accumulation, and the dynamic variable load time history corresponding to each tailings accumulation condition is determined. Considering the self-weight effect and eliminating the spatial variability of material parameters, the distribution law of excess pore water pressure and the evolution law of consolidation ratio under different tailings accumulation methods, different boundary drainage capacities and different accumulation rates are obtained by the controlled variable method. Based on the distribution law of ultrastatic pore water pressure and the evolution law of consolidation ratio, the influence mechanism of tailings accumulation mode, self-weight effect, accumulation rate, accumulation period and accumulation duration on tailings deposition-consolidation behavior is determined, and the layered tailings deposition-consolidation behavior analysis is completed.

[0025] The above-described solution of the present invention has the following beneficial effects: The present invention provides a method for analyzing the sedimentation-consolidation behavior of layered tailings based on the ore discharge method. It systematically realizes the simulation and analysis of the entire process of tailings sedimentation-consolidation. By constructing a physical model, governing equations, coupled numerical model and final analysis model in sequence, a complete technical solution is formed from theoretical modeling, numerical implementation to mechanism revelation. It covers the entire process of tailings from the beginning of sedimentation to the completion of consolidation, and overcomes the limitation of existing methods that often only focus on a single link. The present invention provides a method for analyzing the sedimentation and consolidation behavior of layered tailings based on ore discharge methods. This method effectively reveals the real influence mechanism of dynamic stacking methods on consolidation behavior. By applying three different dynamic variable loads—continuous stacking, cyclic stacking, and intermittent stacking—it can accurately capture the complex ore discharge operation mode at the engineering site. This method can quantitatively compare the accumulation and dissipation law of excess pore water pressure under different stacking methods, thereby revealing the superposition effect of stacking rate and the drainage window effect of stacking cycle. This solves the problem that traditional constant load consolidation theory cannot reflect the dynamic loading process. The present invention provides a method for analyzing the sedimentation-consolidation behavior of layered tailings based on ore discharge methods. This method comprehensively considers the self-weight effect and material spatial variability in the model. Considering the self-weight effect avoids a systematic underestimation of excess pore water pressure in the early stages of sedimentation-consolidation, making the pore pressure distribution closer to reality. Considering material spatial variability overcomes the shortcomings of traditional homogeneous or equivalent homogeneous models that systematically underestimate or overestimate the consolidation ratio, ensuring the reliability of the prediction results. The present invention provides a method for analyzing the sedimentation-consolidation behavior of layered tailings based on discharge methods. This method clearly quantifies the coupling effects of multiple factors. By controlling variables, it can independently separate and quantify the coupling relationship between the accumulation rate, accumulation period, and boundary drainage capacity with tailings consolidation behavior. Based on this, key conclusions guiding engineering practice can be drawn. Furthermore, the step of embedding the constructed tailings sedimentation-consolidation coupled numerical model into the built-in module of finite element analysis software lowers the technical threshold for developing complex programs, making the method highly versatile and easy to migrate and apply across different engineering cases and software platforms. This facilitates its promotion in engineering design and safety assessment practices. Other beneficial effects of the present invention will be described in detail in the following detailed description section. Attached Figure Description

[0026] Figure 1 This is a flowchart of the steps of the present invention; Figure 2 This is a simplified schematic diagram of the sedimentation-consolidation behavior of layered tailings according to the present invention; Figure 3 This is a comparison chart of the numerical simulation results of the present invention and the pore water pressure distribution curves monitored by field tests; Figure 4The dynamic variable load time history curves corresponding to the three tailings accumulation conditions of the present invention are shown. Figure 5 This is a graph showing the effect of the deposition rate on the excess pore water pressure distribution of the present invention, where (a) is... 1d Ignoring its own weight, (b) is 1d Considering its own weight, (c) is 5d neglecting its own weight, (d) is 5d considers its own weight; Figure 6 The graph shows the effect of the stacking rate on the consolidation ratio of the present invention, where (a) represents the result without considering self-weight, (b) represents the result with considering self-weight, and (c) represents the relative error of the predicted consolidation ratio without considering self-weight. Figure 7 (a) is a consolidation ratio curve for different stacking durations. Figure 7 (b) is a graph showing the difference in the calculated consolidation ratio under fully permeable boundary conditions and semi-permeable boundary conditions. Detailed Implementation

[0027] The following specific examples illustrate the implementation of this disclosure. Those skilled in the art can easily understand other advantages and effects of this disclosure from the content disclosed in this specification. Obviously, the described embodiments are only a part of the embodiments of this disclosure, and not all of them. This disclosure can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of this disclosure. It should be noted that, in the absence of conflict, the following embodiments and features in the embodiments can be combined with each other. Based on the embodiments in this disclosure, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this disclosure.

[0028] It should be noted that various aspects of embodiments within the scope of the appended claims are described below. It will be apparent that the aspects described herein can be embodied in a wide variety of forms, and any particular structure and / or function described herein is merely illustrative. Based on this disclosure, those skilled in the art will understand that one aspect described herein can be implemented independently of any other aspect, and two or more of these aspects can be combined in various ways. For example, any number of aspects set forth herein can be used to implement the device and / or practice the method. Additionally, this device and / or method can be implemented using structures and / or functionalities other than one or more of the aspects set forth herein.

[0029] It should also be noted that the illustrations provided in the following embodiments are merely schematic representations of the basic concept of this disclosure. The illustrations only show components relevant to this disclosure and are not drawn according to the actual number, shape, and size of components in implementation. In actual implementation, the type, quantity, and proportion of each component can be arbitrarily changed, and the component layout may be more complex. Furthermore, specific details are provided in the following description to facilitate a thorough understanding of the examples. However, those skilled in the art will understand that the described aspects can be practiced without these specific details.

[0030] Embodiments of the present invention provide a method for analyzing the sedimentation-consolidation behavior of layered tailings based on the ore discharge method, comprising the following steps: S1, construct a physical model for analyzing the sedimentation-consolidation behavior and mechanism of tailings.

[0031] In this embodiment, a simplified schematic diagram of the layered tailings deposition-consolidation behavior is shown below. Figure 2 As shown, it consists of a homogeneous layer with several heterogeneous mechanical parameters (permeability coefficient). The structure consists of a suspension zone at the top (approximately an impermeable boundary) and horizontal drainage pipes at the bottom (approximately a semi-permeable boundary). To quantitatively characterize the accumulation rate, a... (m / d) is used as the daily tailings accumulation thickness, and the time-varying loading rate is defined accordingly. ,in Tailings saturation density. Tailings accumulation load. As a dynamic variable load, its evolution is dynamically controlled by the tailings accumulation method, characterizing the overload pressure (dimension: kPa) formed by the continuous accumulation of newly added tailings above the consolidation zone, and:

[0032] It should be noted that the tailings accumulation load The tailings, together with their own weight, drive the dissipation of excess pore water pressure and the deposition-consolidation process. Therefore, based on the requirements of engineering solvability, the following basic assumptions are proposed: during the deposition-consolidation process, the tailings in the consolidation zone are in a fully saturated state, and both the tailings body and the pore water are considered as incompressible media; the seepage obeys Darcy's law in isotropic homogeneous media; the creep characteristics and structural effects of the tailings body are not considered, and it is assumed that the consolidation deformation is entirely due to the dissipation of excess pore water pressure.

[0033] S2, construct the control equation, continuity equation, boundary conditions, and consolidation equation of the tailings body.

[0034] In this embodiment, the consolidation control equation and continuity equation of the tailings body can be expressed as:

[0035]

[0036]

[0037] in, For the first Pore ​​water pressure in the layer Number the tailings layer. This represents the total number of tailings layers. The consolidation coefficient (m) 2 / s), For depth coordinates (m). For time (s), The consolidation coefficient is denoted as (m / s). For the first The thickness of the layer.

[0038] The horizontal drainage pipe is simplified as a semi-permeable boundary with quantifiable drainage capacity, its upper boundary ( ) is represented as:

[0039] lower boundary ( , The total thickness is expressed as:

[0040] in, and The semi-permeability coefficients of the upper and lower boundaries are respectively, when At that time, it was an impermeable boundary. It is a completely permeable boundary.

[0041] In addition, consider the initial condition of its own weight ( )as follows:

[0042] in, For the first Effective unit weight of tailings (kN / m³) 3 ), For the first The effective density of tailings below the tailings layer, and the first The tailings of the layers are all located in the first layer. Below the tailings layer.

[0043] To quantitatively characterize the consolidation development process of the entire tailings body, an average degree of consolidation is introduced. The expression is:

[0044] S3 constructs a tailings deposition-consolidation coupled numerical model and embeds it into the built-in module of the finite element analysis software.

[0045] In this embodiment, COMSOL Multiphysics finite element analysis software is used for numerical simulation. Due to its built-in coefficient-type partial differential equation (PDE) module, it is widely used in the field of consolidation characteristic analysis compared to other finite element analysis software, and its feasibility and effectiveness in handling consolidation problems have been empirically verified by the academic community. Based on this advantage, this embodiment constructs a tailings deposition-consolidation coupled numerical model through secondary development of this module.

[0046] Specifically, the governing equations of the constructed tailings sedimentation-consolidation coupled numerical model are expressed as follows:

[0047] in, For quality coefficient, The diffusion coefficient is... The absorption coefficient is... The hindrance coefficient is... For source terms, For conservative flux convection coefficient, To conserve flux source terms, This is the convection coefficient.

[0048] COMSOL Multiphysics provides various boundary condition types, among which the Robin boundary condition corresponding to the Flux / Source condition is suitable for describing the behavior of semi-permeable boundaries. Its upper and lower boundary equations can be expressed as follows:

[0049]

[0050] in, For boundary flux, , These are the boundary absorption terms for the bottom and top boundaries, respectively. Substituting the tailings consolidation governing equation and the continuity equation into the model governing equation, we obtain:

[0051] in, The specific weight of water (kN / m³) 3 ).

[0052] Substituting the upper and lower boundary equations of the horizontal drainage pipe into the upper and lower boundary equations of the Robin boundary conditions, we get:

[0053] Therefore, by inputting the model control equations and boundary equations into the COMSOL coefficient-type partial differential equation module, and then using this module in conjunction with the COMSOL Multiphysics finite element analysis software to numerically simulate the tailings deposition-consolidation process, corresponding numerical simulation results can be obtained, which can be used to further analyze the tailings deposition-consolidation behavior and mechanism.

[0054] It should be noted that the numerical simulation results obtained by this method are compared with the field measured data, and the results show good agreement, proving the feasibility of this method in practical engineering applications. Specifically, the experiment simulated the impact of slope load caused by the construction of a large dam, and its engineering applicability was verified by comparing field monitoring data from Bilotta and Viggiani. The maximum slope load was 100 kPa, gradually applied over 74 days and then maintained for 884 days, with varying load values. It is expressed as follows:

[0055] The experiment monitored a 22m thick silty clay layer (overlain by a permeable silty sand layer). Underlying permeable sandy soil layer The pore water pressure response of the simulation is shown in Table 1, with specific parameters listed below. The numerical simulation results are compared with the pore water pressure distribution curves obtained from field tests. Figure 3 As shown in the figure, it can be seen that this method is basically consistent with the field test.

[0056]

[0057] S4. A tailings deposition-consolidation analysis model considering self-weight effect and material spatial variability is constructed. By applying dynamic variable loads of continuous stacking, cyclic stacking or intermittent stacking and controlling boundary drainage conditions, numerical simulation is used to obtain the distribution of excess pore water pressure and the evolution law of consolidation ratio. Based on this, the influence mechanism of stacking mode, stacking rate, stacking cycle and drainage boundary on tailings deposition-consolidation behavior is analyzed.

[0058] In this embodiment, this step specifically includes the following sub-steps: S41, construct a tailings sedimentation-consolidation analysis model that divides the tailings layers into several equal-thickness layers in the depth direction, and set the top boundary of the model as an approximately impermeable boundary and the bottom boundary as a semi-permeable boundary.

[0059] S42 sets up multiple tailings accumulation conditions. The tailings accumulation methods corresponding to each tailings accumulation condition include continuous accumulation, cyclic accumulation and intermittent accumulation. The dynamic variable load time history corresponding to each tailings accumulation condition is determined.

[0060] S43. Considering the self-weight effect and eliminating the spatial variability of material parameters, the distribution law of excess pore water pressure and the evolution law of consolidation ratio under different tailings accumulation methods, different boundary drainage capacities and different accumulation rates are obtained by controlling the variable method.

[0061] S44. Based on the distribution law of ultrastatic pore water pressure and the evolution law of consolidation ratio, the influence mechanism of tailings accumulation mode, self-weight effect, accumulation rate, accumulation cycle and accumulation duration on tailings deposition-consolidation behavior is determined, and the layered tailings deposition-consolidation behavior analysis is completed.

[0062] The following case study further illustrates S4. To explore the influence of self-weight, drainage boundary conditions, and heterogeneity on tailings deposition-consolidation behavior under different tailings accumulation methods, this case study establishes a tailings deposition-consolidation analysis model with a depth of 4m based on an actual engineering case. This model is divided into four tailings layers of equal thickness (1m) along the depth direction, with the top boundary (suspension zone) approximately being an impermeable boundary. The bottom boundary (horizontal drainage pipe) is a semi-permeable boundary. Three tailings accumulation scenarios were designed: continuous accumulation, cyclic accumulation, and discontinuous accumulation. The corresponding dynamic variable load time history curves are shown below. Figure 4 As shown in the figure, this model comprehensively considers the stratification characteristics of tailings deposition, the time-varying characteristics of load, and the spatial variability of consolidation parameters, providing a foundation for subsequent numerical simulations.

[0063] The impact of different tailings accumulation methods was analyzed parametrically using the controlled variable method. First, the compressibility modulus of each consolidation layer was determined. The pressure was uniformly set to 6.111 MPa (see table) to eliminate the influence of spatial variability in material parameters. Secondly, the influence of boundary conditions was examined, including the effect of self-weight stress and the impact of differences in boundary drainage capacity. By controlling these parameters, the independent influence of tailings deposition method on the tailings sedimentation and consolidation process can be effectively isolated.

[0064] Then, to reveal the accumulation rate The influence mechanism of tailings sedimentation-consolidation behavior, setting the bottom boundary semi-permeability coefficient. The distribution patterns of excess pore water pressure were compared between models that neglected self-weight and models that considered self-weight. Figure 5 As shown. From the early consolidation results, the model ignoring self-weight ( Figure 5 In (a)), the maximum pore pressure always appears at the top of the model and increases approximately linearly with the increase of the packing rate: when At m / d values ​​of 0.1 / 0.3 / 0.5 / 0.7 / 0.9, the maximum pore pressures are 1.98 / 5.93 / 9.88 / 13.84 / 17.79 kPa, respectively. In comparison, considering the self-weight model ( Figure 5 (b) shows a significant difference, with the location of maximum pore pressure varying with... The increase gradually migrates to shallower areas, with peak values ​​reaching 17.84 / 21.54 / 25.20 / 28.90 / 32.62 kPa, which is approximately 64% lower on average than the model ignoring self-weight (in...). The deviation was highest at m / d, reaching 89%. As consolidation progressed to... =5d( Figure 5 In (c) and (d), the maximum pore pressure in both models is concentrated at the top of the model, but the numerical differences are still significant. This demonstrates that the accumulation rate is highly sensitive to the cumulative effect of pore water pressure. As the sedimentation rate increases, the excess pore water pressure exhibits a significant superposition trend. An excessively rapid accumulation rate leads to a continuous increase in pore pressure, thereby increasing the risk of early instability of the sediment. Simultaneously, neglecting the self-weight effect systematically underestimates the actual pore pressure, especially in the early stages of deposition-consolidation. The deviation ranges from 45% to 89%. Further analysis of the consolidation mechanism reveals that a higher accumulation rate shortens the dissipation time of pore water within the drainage channels, leading to pore pressure accumulation within the tailings mass. Meanwhile, the self-weight effect strengthens the initial stress field in deeper tailings, making the pore pressure distribution more closely resemble the actual situation. Therefore, considering self-weight and rationally controlling the accumulation rate are crucial for accurately predicting tailings deposition-consolidation behavior.

[0065] Figure 6 The influence mechanism of the accumulation rate on the sedimentation-consolidation behavior of tailings was further revealed based on the consolidation ratio index. The results show that, neglecting the self-weight effect ( Figure 6 (a) shows that the consolidation curves at different packing rates basically overlap, indicating that the consolidation ratio is not sensitive to changes in the packing rate. However, when considering the self-weight effect in actual working conditions ( Figure 6 (b) shows a significant difference in the consolidation process: as the accumulation rate decreases, the tailings consolidation efficiency increases significantly, indicating that gravity plays a crucial role in accelerating pore water dissipation and promoting consolidation. To further quantify the differences between the two models, a relative deviation index is introduced for comparative analysis, such as... Figure 6 As shown in (c), Figure 6 (c)

[0066] in, and The figures represent the consolidation ratios considering and ignoring self-weight, respectively. The results show that ignoring the self-weight effect systematically underestimates the consolidation ratio, and this underestimation is particularly significant under ore dumping conditions. The effect of self-weight gradually weakens with increasing dumping time, but the deviation remains large in the early stages. This demonstrates that the self-weight effect has a significant impact on the tailings deposition-consolidation process, and it is recommended to rationally control the dumping rate to improve the consolidation efficiency of tailings. Therefore, the influence of self-weight on the deposition-consolidation process will be considered in subsequent analyses.

[0067] To further explore the effect of different stacking periods on consolidation properties, a stacking rate ( ) was selected. A comparative analysis was conducted on the cyclic stacking conditions at rates of 0.3 m / d and 0.5 m / d. Simulation results show that under different stacking cycle conditions, higher stacking rates lead to a significant accumulation of excess pore water pressure, thereby reducing the overall consolidation efficiency. Comparison of different cycle periods reveals that using a larger cycle... The optimal stacking method facilitates the gradual dissipation of pore water pressure, with its advantages becoming increasingly apparent as the stacking time increases. Especially in the later stages of stacking, the consolidation ratio curve for long-cycle stacking is significantly higher than that for short-cycle stacking, demonstrating superior long-term consolidation performance. This demonstrates the coupling mechanism between the stacking cycle and the stacking rate: appropriately extending the cycle period can significantly improve pore pressure dissipation and consolidation.

[0068] To further explore the influence mechanism of accumulation duration on tailings deposition-consolidation behavior, numerical simulation and analysis were conducted for discontinuous accumulation mode. Figure 7 (a) shows the total consolidation period fixed at 5 days and the total accumulation volume at 2.5 m. 3 The effects of different stacking durations (1d, 3d, 5d) and bottom boundary semi-permeability coefficient on the evolution of consolidation ratio under different depth conditions were investigated. The results show that the consolidation ratio generally increases with time. In the early stages of consolidation, the consolidation ratio is relatively low for the shorter stacking duration (1d), but in the later stages, its final consolidation effect is significantly better than that of the previous conditions. 3D and The 5-day working condition revealed a key mechanism: prolonged accumulation time significantly reduces final consolidation efficiency; simultaneously, enhanced boundary drainage capacity (significantly) It can effectively promote the consolidation process.

[0069] Figure 7 (b) The difference in consolidation degree under fully permeable and semi-permeable boundary conditions was further compared on day 5. The results show that, with... As the concentration increases, the difference in consolidation degree gradually decreases. When the difference in consolidation degree between the two boundary conditions exceeds a certain threshold, it can be less than 5%, indicating that a strong drainage capacity can mitigate the impact of boundary condition differences on consolidation. Therefore, given the target difference threshold and the packing method, the required minimum drainage capacity can be determined. .

[0070] Furthermore, comparing the consolidation ratios on day 5 of the homogeneous model, equivalent homogeneous model, and heterogeneous model under continuous stacking methods (different stacking rates) reveals that the homogeneous model generally underestimates the consolidation ratio, while the equivalent homogeneous model tends to overestimate it. The faster the stacking rate, the more significant the differences among the three. Further analysis shows that the equivalent homogeneous model underestimates the consolidation ratio in the early stages of consolidation, while overestimating it in the later stages. The fundamental reason for this phenomenon is that the experimentally measured consolidation coefficient of tailings clay increases with depth, while the bottom layer consolidation coefficient of the equivalent homogeneous model is lower than that of the heterogeneous model. This results in the equivalent homogeneous model having a weaker pore water pressure dissipation capacity in the early stages of consolidation, leading to an underestimation of the consolidation ratio. Therefore, in tailings dam engineering practice, it is crucial to emphasize layered sampling and heterogeneous modeling. On the one hand, field surveys must ensure the acquisition of representative parameters for each sedimentary layer; on the other hand, numerical simulations should fully consider the spatial variability of material properties. Therefore, it can significantly improve the accuracy of consolidation prediction and provide a reliable basis for the safe operation of tailings dams.

[0071] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0072] The above embodiments are merely illustrative of several implementation methods of this application, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this application should be determined by the appended claims.

Claims

1. A method for analyzing the sedimentation-consolidation behavior of layered tailings based on ore discharge methods, characterized in that, Includes the following steps: Construct a physical model for the analysis of tailings deposition-consolidation behavior and mechanism; Construct the consolidation control equation, continuity equation, boundary conditions, and consolidation equation for the tailings body; A numerical model of tailings deposition-consolidation coupling was constructed and embedded into a built-in module of the finite element analysis software; A tailings deposition-consolidation analysis model considering self-weight effect and material spatial variability was constructed. By applying dynamic variable loads of continuous, cyclic, or intermittent stacking and controlling boundary drainage conditions, numerical simulation was used to obtain the distribution of excess pore water pressure and the evolution of consolidation ratio. Based on this, the influence mechanism of stacking mode, stacking rate, stacking period, and drainage boundary on tailings deposition-consolidation behavior was analyzed.

2. The method for analyzing the sedimentation-consolidation behavior of layered tailings based on discharge methods according to claim 1, characterized in that, The physical model for analyzing the sedimentation-consolidation behavior and mechanism of tailings consists of a homogeneous layer with heterogeneous dry mechanical parameters and a permeability coefficient of... The top is a suspension zone, set as an impermeable boundary, and the bottom is a horizontal drain pipe, set as a semi-permeable boundary. The time-varying load rate is defined based on the daily tailings accumulation thickness. ,in Set tailings accumulation load to saturate specific gravity. It is dynamically controlled by the tailings accumulation method, and represents the overload pressure formed by the continuous accumulation of newly added tailings above the consolidation zone.

3. The method for analyzing the sedimentation-consolidation behavior of layered tailings based on discharge methods according to claim 2, characterized in that, The formula for calculating the tailings accumulation load is: 。 4. The method for analyzing the sedimentation-consolidation behavior of layered tailings based on discharge methods according to claim 2, characterized in that, The governing equations for tailings consolidation and the continuity equation are set as follows: in, For the first Pore ​​water pressure in the layer Number the tailings layer. This represents the total number of tailings layers. The consolidation coefficient is . For depth coordinates, For time, For the first The thickness of the layer.

5. The method for analyzing the sedimentation-consolidation behavior of layered tailings based on discharge methods according to claim 4, characterized in that, When setting boundary conditions, the boundary conditions for the horizontal drain pipe are set to semi-permeable boundary. The upper boundary of the horizontal drain pipe is represented as follows: The lower boundary is represented as: in, and These are the semi-permeability coefficients of the upper and lower boundaries, respectively. This is the total thickness.

6. The method for analyzing the sedimentation-consolidation behavior of layered tailings based on discharge methods according to claim 4, characterized in that, When setting the consolidation equation, the expression for the initial condition considering self-weight is: in, For the first Effective density of tailings. For the first The effective density of tailings below the tailings layer, and the first The tailings of the layers are all located in the first layer. Below the tailings layer; Introducing average degree of consolidation The expression is: 。 7. The method for analyzing the sedimentation-consolidation behavior of layered tailings based on discharge methods according to claim 6, characterized in that, The governing equations of the constructed tailings sedimentation-consolidation coupled numerical model are expressed as follows: in, For quality coefficient, The diffusion coefficient is... The absorption coefficient is... The hindrance coefficient is... For source terms, For conservative flux convection coefficient, To conserve flux source terms, The convection coefficient; Substituting the tailings consolidation control equation and the continuity equation into the model control equation, we obtain: in, It is the density of water.

8. The method for analyzing the sedimentation-consolidation behavior of layered tailings based on discharge methods according to claim 7, characterized in that, The upper and lower boundary equations of the Robin boundary conditions corresponding to the flux / source conditions are expressed as follows: in, For boundary flux, , These are the boundary absorbing terms for the bottom and top boundaries, respectively; Substituting the upper and lower boundary equations of the horizontal drainage pipe into the upper and lower boundary equations of the Robin boundary conditions, we get: 。 9. The method for analyzing the sedimentation-consolidation behavior of layered tailings based on discharge methods according to any one of claims 1-8, characterized in that, A tailings deposition-consolidation analysis model considering self-weight effects and material spatial variability was constructed. By applying dynamic variable loads of continuous, cyclic, or intermittent stacking and controlling boundary drainage conditions, numerical simulations were used to obtain the distribution of excess pore water pressure and the evolution of the consolidation ratio. Based on this, the influence mechanisms of stacking mode, stacking rate, stacking period, and drainage boundary on tailings deposition-consolidation behavior were analyzed, including: A tailings sedimentation-consolidation analysis model was constructed, which divided the tailings layers into several equal-thickness layers along the depth direction. The top boundary of the model was set as an impermeable boundary and the bottom boundary as a semi-permeable boundary. Multiple tailings accumulation conditions are set up, and the tailings accumulation methods corresponding to each tailings accumulation condition include continuous accumulation, cyclic accumulation and intermittent accumulation, and the dynamic variable load time history corresponding to each tailings accumulation condition is determined. Considering the self-weight effect and eliminating the spatial variability of material parameters, the distribution law of excess pore water pressure and the evolution law of consolidation ratio under different tailings accumulation methods, different boundary drainage capacities and different accumulation rates are obtained by the controlled variable method. Based on the distribution law of ultrastatic pore water pressure and the evolution law of consolidation ratio, the influence mechanism of tailings accumulation mode, self-weight effect, accumulation rate, accumulation period and accumulation duration on tailings deposition-consolidation behavior is determined, and the layered tailings deposition-consolidation behavior analysis is completed.

Images