A method for predicting the water inflow of mine pits applicable to the coverage of cohesive soil

Abstract

The present invention relates to the field of hydrogeology and discloses a method for predicting the water inflow of mine pits suitable for being covered by cohesive soil, which comprises the following steps: special drilling: monitoring boreholes are drilled in the mine, and undisturbed samples of cohesive soil at different positions are taken respectively, so as to obtain cohesive soil data; data monitoring: using monitoring devices to respectively observe the corresponding data of the boreholes; pumping test: a group of borehole pumping tests are carried out on the mine to obtain the shape of the groundwater flow field of the mine, and at the same time, observation data are collected in real time during the pumping process to obtain pumping test data; water release test: a special device is used to carry out a high-pressure compaction water release test on the undisturbed sample of cohesive soil. Obtaining cohesive soil data through special drilling lays a foundation for subsequent analysis. Data monitoring grasps the dynamics of cohesive soil in real time and combines with the data of special drilling to build a basis for studying its characteristics and variation laws. The pumping test studies the interaction between groundwater and cohesive soil and provides key support for prediction.

Description

Technical Field

[0001] The present invention relates to the technical field of hydrogeology, and particularly to a method for predicting the water inflow of a mine pit applicable to the coverage of cohesive soil. Background Art

[0002] In the field of hydrogeology, mines are generally classified into three categories according to the different main water - filled aquifers of the ore deposits. One is the ore deposit mainly filled with pore aquifers, simply referred to as pore - filled ore deposits, and the aquifer is the Quaternary sand, sand - gravel and pebble layer; the second is the ore deposit mainly filled with fissure aquifers, simply referred to as fissure - filled ore deposits, and the aquifer is the weathered fissure or tectonic fissure aquifer of bedrock; the third is the ore deposit mainly filled with karst aquifers, simply referred to as karst - filled ore deposits, and the aquifer is the limestone karst water aquifer.

[0003] In the past in the hydrogeological field, cohesive soil was generally regarded as an aquitard. However, we found in actual work that the void ratio of cohesive soil is very large, generally 1.0 - 2.0, and saturated cohesive soil itself has a quite rich water content. When there is a thick Quaternary and cohesive soil covering the upper part of the mine, under the mine drainage conditions, the pressure of deep groundwater drops significantly. Under the action of the hydraulic gradient, the cohesive soil layer begins to release water, and the increase in effective stress causes the soil to undergo compression consolidation. The water released from the cohesive soil will become an important water - filling source of the ore deposit, which will not only increase the water inflow of the mine pit, but also trigger a series of geological environment problems such as ground settlement and deformation, causing damage to ground buildings or mine engineering and bringing huge losses. Summary of the Invention

[0004] Aiming at the deficiencies of the prior art, the present invention provides a method for predicting the water inflow of a mine pit applicable to the coverage of cohesive soil, which solves the problems that when there is a thick Quaternary and cohesive soil covering the upper part of the mine, the water released from the cohesive soil will become an important water - filling source of the ore deposit, which will not only increase the water inflow of the mine pit, but also trigger a series of geological environment problems such as ground settlement and deformation, causing damage to ground buildings or mine engineering and bringing huge losses.

[0005] To achieve the above - mentioned purposes, the present invention is realized through the following technical solutions: A method for predicting the water inflow of a mine pit applicable to the coverage of cohesive soil includes the following steps:

[0006] S1. Special drilling: Monitor boreholes in the mine, and at the same time, take undisturbed samples of cohesive soil at different positions to obtain cohesive soil data;

[0007] S2. Data monitoring: Use monitoring devices to respectively observe the corresponding data of the boreholes;

[0008] S3. Pumping test: Conduct a group - borehole pumping test on the mine to obtain the form of the underground water flow field of the mine. At the same time, real - time collect and observe data during the pumping process to obtain pumping test data;

[0009] S4, Water Release Test: Use special equipment to conduct a water release test of cohesive soil in the original state under high pressure on the cohesive soil undisturbed sample. During the test, collect the water samples released by the cohesive soil synchronously to obtain the water release data of the clay.

[0010] S5, Model Establishment: Combine the cohesive soil data, pumping test data, and clay water release data to establish a corresponding model.

[0011] S6, Water Quantity Prediction: Use the corresponding model and the shape of the underground water flow field in the mine, and adopt the finite difference method to establish a calculation model for the compression settlement of cohesive soil, calculate the water release volume during the consolidation of cohesive soil under different compression states, and predict the water release volume under the single-sided drainage condition of cohesive soil at different mining levels.

[0012] S7, Prevention and Control Layout: Obtain the recharge, runoff, and discharge conditions of mine groundwater according to relevant parameters, and combine the water release volume to guide the hydrogeological work of the mine and layout the water prevention and control plan.

[0013] Preferably, in S1, the monitoring boreholes include several layered settlement monitoring boreholes and cohesive soil pore water pressure monitoring boreholes. The undisturbed samples of cohesive soil at different positions are collected by a triple-tube single-action soil sampler during drilling. The different positions include the upper layer, middle layer, and lower layer. The undisturbed samples of cohesive soil are used for the water release test of cohesive soil compression. The cohesive soil data includes the lithology, distribution, and thickness of the cohesive soil.

[0014] Preferably, in S2, the monitoring devices used include the layered settlement observation devices installed using the layered settlement monitoring boreholes and the pore water pressure monitoring devices installed using the cohesive soil pore water pressure monitoring boreholes. The corresponding data includes the settlement amounts at different vertical positions and the change data of the cohesive soil pore water pressure.

[0015] Preferably, in S3, the multiple-well pumping test of the mine is carried out through the pumping well in the mine. The number of pumping wells is 2 to 5, and the diameter is greater than 200 mm. The multiple-well pumping test is to pump water from the pumping wells simultaneously, and observe the water level changes of the pumping wells and the water level observation wells in the mining area at the same time. The time of the multiple-well pumping test is 5 - 45 days. The observation data includes the layered settlement observation data and the cohesive soil pore water pressure monitoring data.

[0016] Preferably, in S4, the special equipment includes a high-pressure consolidation apparatus. The maximum pressure range of the high-pressure consolidation apparatus exceeds two megapascals. The water release test of cohesive soil in the high-pressure state is to conduct a one-dimensional in-situ stress drainage consolidation test on the undisturbed sample of cohesive soil using the high-pressure consolidation apparatus. The clay water release data includes the relationship between stress and strain and its change law during the clay water release compression process, the released water volume, the clay consolidation coefficient Cv, the compression modulus Es, and the vertical permeability coefficient Kv.

[0017] Preferably, the maximum consolidation pressure of the one-dimensional in-situ stress drainage consolidation test is calculated according to the formula P = h * γ, where h represents the thickness of each overlying soil layer and γ represents the unit weight of the overlying soil layer. The thickness of each overlying soil layer is obtained from the settlement monitoring borehole and the pore water pressure monitoring borehole of the cohesive soil, and the unit weight of the overlying soil layer is obtained by using the empirical values of each overlying soil layer or by taking soil samples from each overlying soil layer for laboratory tests.

[0018] Preferably, the corresponding models in S5 include the three-dimensional model of mine cohesive soil and the high-pressure consolidation model. The three-dimensional model of mine cohesive soil is B = H(x, y, z), where H represents the thickness of the cohesive soil at points x, y, z. The high-pressure consolidation model is as follows:

[0019] ;

[0020] ;

[0021] ;

[0022] ;

[0023] ;

[0024] ;

[0025] Where: is the seepage velocity in the clay, is the vertical strain, is the excess hydrostatic pressure, and are the compression moduli, is the viscosity coefficient of the Newtonian dashpot, is the excess pore water pressure, is the time, is the depth, is the three-dimensional model of cohesive soil, is the unit weight of water, is the head difference between the top and bottom of the cohesive soil.

[0026] Preferably, the numerical model of the above formula is established by using the finite difference method for the cohesive soil compression settlement calculation model in S6. The simulated cohesive soil layer is evenly divided into meshes with a length of . Each mesh is represented by a central node. The top boundary of the model is located at the node, and the bottom boundary is located at the position. Each node is:

[0027] , where is expressed as .

[0028] Preferably, the finite difference format of the control equation of the calculation model for the compression settlement of cohesive soil is:

[0029] .

[0030] Preferably, the relevant parameters in S7 include the distribution and water-richness characteristics of the mine aquifer, the dynamic and flow field characteristics of the mine groundwater, and the factors of ore deposit water filling.

[0031] The present invention provides a method for predicting the water inflow of a mine pit applicable to mines covered with cohesive soil. It has the following beneficial effects:

[0032] 1. The present invention obtains cohesive soil data through special drilling, laying a foundation for subsequent analysis. Real-time monitoring of data grasps the dynamics of cohesive soil, combines with the data of special drilling, constructs a basis for studying its characteristics and variation laws. The pumping test studies the interaction between groundwater and cohesive soil, provides key support for prediction. The water release test quantifies the characteristics of cohesive soil, and together with other data, establishes a model to accurately simulate the behavior of cohesive soil, and uses the finite difference method to predict the water inflow, thus solving the problems raised in the background technology.

[0033] 2. The present invention establishes a three-dimensional model of cohesive soil and a high-pressure consolidation model in the mining area, and uses the finite difference method to establish a calculation model for the compression settlement of cohesive soil for water volume prediction, which can fully consider the characteristics of water release due to the compaction of cohesive soil and its complex relationship with the groundwater system, thus significantly improving the accuracy of mine pit water inflow prediction and providing a reliable basis for drainage planning during the mining process of the mine.

[0034] 3. The present invention uses a layered settlement observation device and a pore water pressure monitoring device to observe the settlement amount at different vertical positions of the borehole and the change data of the pore water pressure of cohesive soil in real time, continuously collects relevant data during the pumping test and combines it with the results of the water release test due to the compaction of cohesive soil, and comprehensively analyzes it during the model establishment and water volume prediction process. Thus, not only can the mine pit water inflow be predicted, but also the compression and consolidation of cohesive soil during the mining process of the mine and the resulting ground settlement trend can be deeply understood, so as to comprehensively evaluate the impact of mine mining on the geological environment.

[0035] 4. The present invention predicts the released water volume under the single-sided drainage condition of cohesive soil at different mining levels, reasonably adjusts parameters such as the mining sequence and mining speed, avoids the aggravation of water inflow problems caused by mining activities. At the same time, based on the accurate grasp of the groundwater recharge-discharge conditions, targeted water prevention and control measures are formulated, improving the efficiency and effect of water prevention and control work, reducing the mining cost of the mine, and ensuring the safe production and sustainable development of the mine. Description of the Drawings

[0036] Figure 1 This is the method flow chart of a method for predicting the water inflow of mine pits applicable to clayey soil coverage proposed by the present invention. Specific implementation mode

[0037] Next, in combination with the drawings of the present invention, the technical solutions of the present invention will be clearly and completely described. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0038] Example:

[0039] Please refer to the attached Figure 1 , the embodiment of the present invention provides a method for predicting the water inflow of mine pits applicable to clayey soil coverage, including the following steps:

[0040] S1. Special drilling: Monitor the mine by drilling holes, and at the same time, take undisturbed samples of clayey soil at different positions respectively, so as to obtain clayey soil data; The monitoring drilling in S1 includes several layered settlement monitoring drill holes and clayey soil pore water pressure monitoring drill holes. The undisturbed samples of clayey soil at different positions are collected by a triple-tube single-action soil sampler during drilling. Different positions include the upper layer, the middle layer, and the lower layer. The undisturbed samples of clayey soil are used for the clayey soil consolidation and water release test. The clayey soil data includes the lithology, distribution, and thickness of the clayey soil.

[0041] Specifically, by monitoring the mine by drilling holes and taking undisturbed samples of clayey soil at different positions respectively, clayey soil data is obtained, and detailed information such as the lithology, distribution range, and thickness of the clayey soil at different positions in the mine is obtained, as well as the undisturbed soil samples for subsequent test analysis, so as to initially master the basic geological characteristics of the clayey soil coverage layer, and provide basic data for subsequent research on the physical and mechanical properties of the clayey soil and its change law during the mine exploitation process.

[0042] S2. Data monitoring: Use monitoring devices to observe the corresponding data of the drill holes respectively; The monitoring devices used in S2 include the layered settlement observation devices installed by using the layered settlement monitoring drill holes and the pore water pressure monitoring devices installed by using the clayey soil pore water pressure monitoring drill holes. The corresponding data includes the settlement amount and the change data of the clayey soil pore water pressure at different vertical positions.

[0043] Specifically, by using monitoring devices to observe the corresponding data of boreholes respectively, the dynamic response data of cohesive soil during the mining process (under the influence of pumping, etc.) are obtained. The tracking and monitoring of the changes of cohesive soil in space and time can timely capture the deformation trend of cohesive soil and the change trend of pore water pressure, providing real-time data support for analyzing the consolidation process, seepage characteristics of cohesive soil and its interaction with groundwater, and helping to timely adjust the mining plan and water control measures.

[0044] S3. Pumping test: Conduct a group well pumping test on the mine to obtain the shape of the groundwater flow field in the mine. At the same time, collect observation data in real time during the pumping process to obtain pumping test data. The group well pumping test on the mine in S3 is to conduct a group well pumping test through the pumping main well of the mine. The number of pumping main wells is 2 to 5, with a diameter greater than 200 mm. The group well pumping test is to pump the pumping main wells simultaneously, and observe the water level changes of the pumping main wells and the water level observation wells in the mining area at the same time. The time of the group well pumping test is 5 - 45 days. The observation data include stratified settlement observation data and cohesive soil pore water pressure monitoring data.

[0045] Specifically, by conducting a group well pumping test on the mine, the shape of the groundwater flow field in the mine is obtained. At the same time, collect observation data in real time during the pumping process to obtain pumping test data, so as to obtain the shape of the groundwater flow field in the mine and the comprehensive response data of the cohesive soil and the groundwater system during the pumping process, providing key data for accurately predicting the mine water inflow and evaluating the impact of mining on the groundwater environment, and also providing a basis for optimizing the pumping plan and the design of water control projects.

[0046] S4. Water release test: Use special equipment to conduct a high-pressure compaction and water release test on undisturbed samples of cohesive soil. During the test, collect the water samples released by the cohesive soil synchronously to obtain clay water release data. The special equipment in S4 includes a high-pressure consolidation apparatus. The maximum pressure range of the high-pressure consolidation apparatus exceeds two megapascals. Conducting a high-pressure compaction and water release test on cohesive soil is to conduct a one-dimensional in-situ geostress drainage consolidation test on undisturbed samples of cohesive soil using a high-pressure consolidation apparatus. The clay water release data include the relationship and its variation law between stress and strain during the clay water release and compression process, the amount of water released, the clay consolidation coefficient Cv, the compression modulus Es, and the vertical permeability coefficient Kv. The maximum consolidation pressure of the one-dimensional in-situ geostress drainage consolidation test is calculated according to the formula P = h * γ, where h represents the thickness of each overlying soil layer and γ represents the unit weight of the overlying soil layer. The thickness of each overlying soil layer is obtained from the settlement monitoring boreholes and the cohesive soil pore water pressure monitoring boreholes. The unit weight of the overlying soil layer is obtained using the empirical values of each overlying soil layer or by taking soil samples from each overlying soil layer for laboratory tests.

[0047] Specifically, through the use of special equipment to conduct a compaction and water release test on undisturbed samples of cohesive soil under high pressure, water samples released by the cohesive soil are synchronously collected during the test, thereby obtaining clay water release data, which can quantitatively describe the water release capacity and compression consolidation characteristics of cohesive soil, providing core parameters for establishing an accurate model to predict the water release volume and settlement amount of cohesive soil during mining. At the same time, it fills the data gap in the study of cohesive soil characteristics under this special condition, provides a scientific basis for accurately evaluating the contribution of cohesive soil as a water filling source to the mine water inflow, and also provides important parameter support for analyzing the ground settlement mechanism.

[0048] S5. Model establishment: Combine the cohesive soil data, pumping test data, and clay water release data to establish corresponding models; the corresponding models in S5 include a three-dimensional model of cohesive soil in the mining area and a high-pressure consolidation model. The three-dimensional model of cohesive soil in the mining area is B = H(x, y, z), where H represents the thickness of the cohesive soil at points x, y, z. The high-pressure consolidation model is as follows:

[0049] ;

[0050] ;

[0051] ;

[0052] ;

[0053] ;

[0054] ;

[0055] Where: is the seepage velocity in the clay, is the vertical strain, is the excess hydrostatic pressure, and are the compression moduli, is the viscosity coefficient of the Newtonian dashpot, is the excess pore water pressure, is the time, is the depth, is the three-dimensional model of cohesive soil, is the unit weight of water, is the head difference between the top and bottom of the cohesive soil.

[0056] Specifically, by combining cohesive soil data, pumping test data, and clay water release data, a corresponding model is established, thus constructing a mathematical model that can reflect the spatial distribution and physical and mechanical behavior of cohesive soil in the mine geological environment, thereby realizing the digital and quantitative description of the complex characteristics of cohesive soil and the hydrogeological conditions of mine groundwater, transforming the actual geological body and physical process into a model that can be numerically calculated and analyzed, providing a theoretical framework and calculation platform for accurately predicting the deformation, water release, and interaction with groundwater of cohesive soil in the future, and being able to simulate the changes of cohesive soil and groundwater under different mining conditions in a virtual environment, providing a decision-making support tool for optimizing the mining plan and water control strategy.

[0057] S6, Water volume prediction: Using the corresponding model and the morphology of the mine groundwater flow field, a calculation model for the compression settlement of cohesive soil is established by the finite difference method, calculating the water release volume due to consolidation of cohesive soil under different compression states, and predicting the water release volume under the single-sided drainage condition of cohesive soil at different mining levels; The numerical model of the above formula is established by the finite difference method in the calculation model for the compression settlement of cohesive soil in S6, and the layer of cohesive soil is evenly divided into meshes with a length of , and each mesh is represented by a central node. The top boundary of the model is located at the node, and the bottom boundary is located at . Each node is:

[0058] , where is expressed as ; The finite difference format of the control equation of the calculation model for the compression settlement of cohesive soil is:

[0059] .

[0060] Specifically, by using the corresponding model and the morphology of the mine groundwater flow field, a calculation model for the compression settlement of cohesive soil is established by the finite difference method, calculating the water release volume due to consolidation of cohesive soil under different compression states, and predicting the water release volume under the single-sided drainage condition of cohesive soil at different mining levels, thereby obtaining a quantitative prediction result of the possible water inflow of cohesive soil during future mine mining, realizing the accurate prediction of the water release due to consolidation of cohesive soil in the mine water inflow, being able to provide accurate data basis for mine enterprises to plan drainage facilities in advance and formulate water control measures, and at the same time helping to evaluate the impact of mine mining on water resources and water environment, realizing the reasonable management and protection of water resources, thus making the water control work during mine mining more targeted and effective, reducing the mine safety risks and economic losses caused by water inflow problems.

[0061] S7. Prevention and control layout: Obtain the recharge-discharge conditions of mine groundwater according to relevant parameters, combine the released water volume to guide the hydrogeological work of the mine, and layout the water prevention and control plan; the relevant parameters in S7 include the distribution and water-richness characteristics of mine aquifers, the dynamic and flow field characteristics of mine groundwater, and the factors of ore deposit water filling.

[0062] Specifically, by obtaining the recharge-discharge conditions of mine groundwater according to relevant parameters, combining the released water volume to guide the hydrogeological work of the mine, and laying out the water prevention and control plan, the effective connection from geological exploration and data prediction to actual engineering prevention and control measures is realized, and the previous research results are transformed into specific action plans, ensuring that the mine can effectively respond to groundwater problems during the mining process, guaranteeing the safe production of the mine, while taking into account water resource protection and ecological environment balance.

[0063] Through the coordinated implementation of each step, various data of cohesive soil and relevant characteristics of groundwater are obtained, a model is constructed to quantify the characteristics of cohesive soil and simulate its behavior, and accurate prediction of the water inflow of the mine pit is realized. It can not only comprehensively evaluate the impact of mining on the geological environment, but also optimize the mining plan and water prevention and control measures. Thus, when the upper part of the mine is covered with thick Quaternary and cohesive soil, the water released from the cohesive soil will become an important water filling source for the ore deposit, which will not only increase the water inflow of the mine pit, but also cause a series of geological environment problems such as ground settlement and deformation, resulting in the damage of ground buildings or mine projects and bringing huge losses.

[0064] In the compaction water-releasing and water-filling ore deposit, the water inflow of the mine pit can be divided into two parts. One part is the water volume released by the compaction of cohesive soil, and the other part is the water volume entering the mine pit through other channels (such as lateral recharge of regional groundwater).

[0065] This method first presets a dewatering level of the mine, secondly determines the change in the void ratio of cohesive soil, including the change amount and change rate, under this dewatering level of the mine according to the three-dimensional model of cohesive soil and the high-pressure consolidation model, and finally calculates the compaction water release volume considering the three-dimensional distribution state of cohesive soil and the shape of the dewatering flow field.

[0066] The water volume released by the compaction of cohesive soil can be calculated separately through the compaction settlement calculation model of cohesive soil, distinguishing the above two different water volumes. At the same time, the ground settlement amount caused by mine drainage can be predicted, enabling the mine to adopt different water prevention and control measures for different water inflow sources, making the mine production and construction safer and the production cost lower.

[0067] Although the embodiments of the present invention have been shown and described, for those of ordinary skill in the art, it can be understood that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for predicting the water inflow of a mine pit applicable to the coverage of cohesive soil, characterized in that, It includes the following steps: S1. Special drilling: Monitor the mine by drilling monitoring boreholes, and simultaneously take undisturbed samples of cohesive soil at different positions to obtain cohesive soil data; S2. Data monitoring: Use monitoring devices to respectively observe the corresponding data of the boreholes; The monitoring devices used in S2 include the settlement observation device installed by using the multi - layer settlement monitoring borehole and the pore water pressure monitoring device installed by using the cohesive soil pore water pressure monitoring borehole. The corresponding data includes the settlement amount at different vertical positions and the change data of the cohesive soil pore water pressure; S3. Pumping test: Conduct a group - hole pumping test on the mine to obtain the form of the underground water flow field of the mine. At the same time, collect and observe data in real time during the pumping process to obtain pumping test data; S4. Water release test: Use special equipment to conduct a high - pressure consolidation water release test on the undisturbed sample of cohesive soil. During the test, synchronously collect the water samples released by the cohesive soil to obtain clay water release data; The special equipment in S4 includes a high - pressure consolidation apparatus. The maximum pressure range of the high - pressure consolidation apparatus exceeds 2 MPa. Conducting the high - pressure consolidation water release test of cohesive soil is to conduct a one - dimensional in - situ geostress drainage consolidation test on the undisturbed sample of cohesive soil by using the high - pressure consolidation apparatus. The clay water release data includes the relationship between stress and strain and its variation law during the clay water release and compression process, the amount of water released, the clay consolidation coefficient Cv, the compression modulus Es, and the vertical permeability coefficient Kv; S5. Model establishment: Combine the cohesive soil data, pumping test data, and clay water release data to establish corresponding models; The corresponding models in S5 include a three - dimensional model of cohesive soil in the mining area and a high - pressure consolidation model. The three - dimensional model of cohesive soil in the mining area is B = H(x, y, z), where H represents the thickness of the cohesive soil at points x, y, z. The high - pressure consolidation model is as follows: u(z, 0)=0; u(0, t)=0; u(B,t) = -γ w Δh(t); Where: q is the seepage velocity in the clay, Kv is the vertical permeability coefficient, ε z is the vertical strain, u is the excess hydrostatic pressure, E0 and E1 are the compression moduli, η is the viscosity coefficient of the Newtonian dashpot, u is the excess pore water pressure, t is the time, z is the depth, B is the three-dimensional model of cohesive soil, γ w is the unit weight of water, Δh(t) is the head difference between the top and bottom of the cohesive soil; S6. Water volume prediction: Use the corresponding models and the form of the underground water flow field of the mine, and establish a calculation model for the consolidation settlement of cohesive soil by using the finite - difference method to calculate the amount of water released during the consolidation of cohesive soil in different compression states, and predict the amount of water released under the single - sided drainage condition of cohesive soil at different mining levels; In the compression settlement calculation model of cohesive soil in S6, the numerical model of the above formula is established by the finite difference method. The cohesive soil layer is evenly divided into N grids with a length of Δz, and each grid is represented by a central node. The top boundary of the model is located at the 1-1 / 2 node, and the bottom boundary is located at N+1 / 2. Each node z i is: wherein is expressed as S7. Prevention and control layout: Obtain the recharge - runoff - discharge conditions of mine groundwater according to relevant parameters, combine the amount of water released to guide the hydrogeological work of the mine, and layout the water prevention and control plan.

2. The prediction method for the water inrush volume of a mine pit applicable to the coverage of cohesive soil according to claim 1, wherein: The monitoring boreholes carried out in S1 include several multi - layer settlement monitoring boreholes and cohesive soil pore water pressure monitoring boreholes. The undisturbed samples of cohesive soil at different positions are collected by using a triple - tube single - action soil sampler during drilling. The different positions include the upper layer, the middle layer, and the lower layer. The undisturbed samples of cohesive soil are used for the high - pressure consolidation water release test of cohesive soil. The cohesive soil data includes the lithology, distribution, and thickness of the cohesive soil.

3. A method for predicting the water inflow of a mine pit suitable for being covered by cohesive soil according to claim 1, characterized in that: The multi-well pumping test on the mine in S3 is carried out through the large pumping well of the mine. The number of the large pumping wells is 2 to 5, and the diameter is greater than 200 mm. The multi-well pumping test is to pump water from the large pumping wells simultaneously, and observe the water level changes of the large pumping wells and the water level observation wells in the mining area at the same time. The time of the multi-well pumping test is 5 - 45 days. The observation data includes layered settlement observation data and cohesive soil pore water pressure monitoring data.

4. A method for predicting the water inflow of a mine pit applicable to cohesive soil coverage according to claim 1, characterized in that: The maximum consolidation pressure of the one-dimensional in-situ ground stress drainage consolidation test is calculated according to the formula P = h * γ, where h represents the thickness of each overlying soil layer, and γ represents the unit weight of the overlying soil layer. The thickness of each overlying soil layer is obtained from the settlement monitoring borehole and the cohesive soil pore water pressure monitoring borehole. The unit weight of the overlying soil layer is obtained by using the empirical values of each overlying soil layer or taking soil samples from each overlying soil layer for laboratory tests.

5. A method for predicting the water inflow of a mine pit suitable for being covered by cohesive soil according to claim 1, characterized in that: The finite difference format of the control equation of the calculation model for the compression settlement of cohesive soil is as follows:

6. The prediction method of mine pit water inflow applicable to the coverage of cohesive soil according to claim 1, characterized in that: The relevant parameters in S7 include the distribution and water-richness characteristics of the mine aquifer, the dynamic and flow field characteristics of the mine groundwater, and the factors of ore deposit water filling.

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