Method for evaluating waterproof permeability of gangue fluidized slurry compacted body

Abstract

The invention discloses a method for evaluating the water-proof permeability of a gangue fluidized slurry compaction body, and belongs to the field of evaluation of a gangue slurry compression permeability water-proof effect. The method comprises the following steps: 1) analyzing the influence degree of gangue particle size grading, axial pressure, water pressure and cement mixing amount on the waterproof permeability of the compacted slurry; 2) testing the waterproof permeability of the compacted filling body through a test scheme of the waterproof permeability of the gangue fluidized slurry compaction body; (3) analyzing the permeability change condition of the gangue fluidized slurry compacted body under the conditions of different gangue particle size grading, axial pressure, water pressure and cement mixing amount; and 4) constructing a permeation grading standard of the gangue fluidized slurry compacted body covering four evaluation indexes of gangue particle size grading, axial pressure, water pressure and cement mixing amount, and performing grading evaluation on the waterproof permeation effect of the gangue fluidized slurry compacted body. The method is easy to operate and low in test cost, data obtained through evaluation are closer to field filling, and the method can be widely applied to the field of filling water-preserved mining.

Description

Technical Field

[0001] The invention belongs to the field of evaluation of gangue slurry compression penetration and water-proofing effect, and in particular relates to a method for evaluating the water-proofing and water-proofing performance of a gangue fluidized slurry compaction body. Background Art

[0002] With the increasing emission of coal-based solid waste caused by coal mining, the disposal of mine gangue has gradually become one of the important research directions in the coal field. Gangue is a kind of mine solid waste generated during the mining process that has potential impact on the environment. The harm it causes to the environment mainly includes land occupation, surface subsidence, soil erosion and ecological damage.

[0003] At present, in order to protect the nearby groundwater layer during backfill mining, the engineering application of gangue slurry backfill mining is quite extensive. However, after the gangue slurry is injected into the delamination zone and fracture zone in the subsequent space through the grouting drilling, the excess water in the slurry is continuously lost along the cracks and voids of the rock mass. The aggregate in the gangue slurry is gradually compacted by the gravity of the overlying rock strata, the extrusion of the rock mass and the local stress concentration, forming a whole compacted body in the delamination zone, which plays a bearing and water-proof role in the fracture zone. Therefore, the water-proof permeability characteristics of the compacted body under different stress conditions and water pressure conditions are studied, and the water-proof permeability performance of the compacted body of gangue fluidized slurry is analyzed and evaluated, which can ensure that the filling slurry is injected into the subsequent space to play a bearing and water-proof effect, which has important engineering significance. Summary of the invention

[0004] Purpose of the invention: The problem to be solved by the present invention is to overcome the shortcomings of existing evaluation methods and provide a method for evaluating the water-proof and permeability performance of gangue fluidized slurry compaction bodies.

[0005] To solve the above-mentioned purpose, the present invention provides a method for evaluating the water-proof and permeability performance of a gangue fluidized slurry compaction body, comprising the following steps:

[0006] 1) Based on the phenomenon that the slurry forms a compacted body and seepage occurs after the subsequent space gangue fluidized grouting filling, the influence of gangue particle size distribution, axial pressure, water pressure and cement content on the water-proof and permeable performance of the slurry after compaction is analyzed;

[0007] 2) Determine the test scheme for the water-proof and permeability performance of the compacted body of the fluidized gangue slurry: Use a filling material seepage test system, use a filling body composed of loose gangue with different particle size distributions after water saturation, consider different gangue particle size distributions, axial pressure, water pressure and cement content conditions, and test the water-proof and permeability performance of the compacted filling body; the filling material seepage test system includes a vertically arranged piston-cylinder structure, the piston-cylinder structure includes a cylinder body for accommodating a model filling body, and an axial pressure piston arranged on the top of the model filling body, wherein a seepage inlet is provided at the bottom of the cylinder body, and the piston structure A displacement sensor and a seepage outlet are arranged on it, and pressure sensors and temperature sensors are arranged at different height positions in the filling body of the cylinder body. When in use, the loading device is used to make the piston structure load a constant pressure axial stress to the model specimen in the cylinder body to the working pressure, and the gangue grouting material is injected into the cylinder body through the seepage inlet at the bottom of the cylinder body, and the readings of all pressure sensors and temperature sensors, as well as the displacement value of the displacement sensor are collected in real time, and the injection speed, cumulative injection volume and injection pressure parameters of the constant speed and constant pressure pump are collected in real time; the seepage outlet is weighed by an electronic balance to collect data in real time.

[0008] 3) Using the data obtained from the water-blocking seepage test device, the permeability changes of the gangue fluidized slurry compact under different gangue particle size distribution, axial pressure, water pressure and cement content were analyzed;

[0009] 4) Combined with the permeability evolution of the gangue fluidized slurry compacted body, a permeability grading standard for the gangue fluidized slurry compacted body is constructed, which covers four evaluation indicators: gangue particle size grading, axial pressure, water pressure and cement content. The water-proof and permeability effect of the gangue fluidized slurry compacted body is graded and evaluated. The four evaluation indicators, gangue particle size grading, axial pressure, water pressure and cement content, are used separately or in coordination as needed during the evaluation.

[0010] Furthermore, the subsequent space described in step 1) includes the delamination zone and the fracture zone formed by the overlying rock strata after mining; the phenomenon of seepage of the compacted body refers to the gangue slurry being injected into the delamination zone and the fracture zone in the subsequent space through the grouting drilling hole, and the excess water in the slurry is continuously lost along the cracks and voids of the rock mass, and the aggregate in the gangue slurry is gradually compacted by the gravity of the overlying rock strata, the extrusion of the rock mass and the local stress concentration.

[0011] Furthermore, the water-proof and permeability properties of the slurry after compaction in step 1) are the water-proof and permeability properties of a whole compacted filling body formed in the delamination zone and the fracture zone after the seepage phenomenon occurs in the filling gangue slurry, and the compacted filling body plays a bearing and water-proof role in the delamination zone and the fracture zone; the gangue particle size grading is the main factor affecting the mechanical properties of the gangue fluidized slurry, and the permeability properties of the slurry after compaction change with the change of its own mechanical properties; the axial pressure simulates the scene of the compacted filling body being subjected to pressure in the overlying rock formation, thereby affecting the permeability properties of the slurry compaction body; the water pressure refers to the water pressure generated by the pressure of the overlying aquifer flowing to the compaction body through the water-conducting fracture channel, and the water-proof and permeability properties of the compaction body change greatly under different water pressures. The cement content of different mass proportions will greatly affect the internal heterogeneous structure of the gangue fluidized slurry, and its permeability and water-proof properties will change after the gangue slurry is compacted.

[0012] Further, the water-proof and permeability performance of the compacted filling body in step 2) is tested, including the following steps:

[0013] a. Load the corresponding proportion of gangue slurry into the cylinder, scrape the surface of the material flat, make it 8cm away from the upper port of the cylinder, finally connect the pipeline and check the air tightness again;

[0014] b. The axial pressure piston provides axial stress through water pressure, increases axial pressure by repeated liquid suction and injection, and prepares the compacted filling body by graded loading and pressure maintenance;

[0015] c. Use a horizontal flow pump to pressurize the seepage inlet at the bottom of the cylinder. The seepage outlet pressure at the top of the axial pressure piston is 0. Adjust the inlet pressure from small to large. After the water seeps stably in the compacted filling body, turn on the permeability test switch, and simultaneously record the pressure gradient and seepage flow data, and calculate the permeability of the compacted filling body.

[0016] Furthermore, the graded loading and pressure maintenance is to divide the target loading stress into 4 levels for loading, and each level is pressure maintained for 20 minutes. When the loading stress of each level increases and the water seepage under the pressure maintenance state reaches a stable value, the compacted filling body is in a saturated state, indicating that the preparation of the filling compaction body is completed, and the subsequent water-proof and permeability performance test of the filling compaction body under the axial pressure of this level can be directly carried out;

[0017] Gradual loading is a stress loading method that loads the same filling compaction body step by step, and obtains the seepage data of different factors under various levels of stress from the filling compaction body, thereby reducing the test time and cost;

[0018] The test process of graded loading is as follows: ① determine the stress level values ​​of the graded loading test; ② when the stress level reaches the next stress level determined by the test plan, continue to complete the tests under this stress level and cycle in sequence to the maximum stress level determined by the test plan.

[0019] Furthermore, in the test scheme for the water-proof and permeability performance of the compacted gangue fluidized slurry, two particle size gradations are selected: 0-2 mm and 0-5 mm, wherein the mass ratio of 0.15-2 mm to 0-0.15 mm gangue in 0-2 mm gangue is (0-2):1, and the corresponding slurry concentration is 60%; the mass ratio of 2-5 mm, 0.15-2 mm and 0-0.15 mm gangue in 0-5 mm gangue is (0-0.3):2:1, and the corresponding slurry concentration is 65%.

[0020] Furthermore, the permeability evolution of the gangue fluidized slurry compaction body was analyzed by plotting the line relationship between different indicators and the permeability measured in the experiment, and comprehensively analyzing the growth relationship between each indicator and the permeability.

[0021] Furthermore, the permeability classification of the gangue fluidized slurry compaction body is formulated based on the permeability coefficient. Based on the porous medium characteristics of the compacted filling body, the permeability and permeability coefficient are equivalently converted. The conversion formula is:

[0022]

[0023] Where: K-permeability coefficient, cm / s; ρ-water density, g / cm; g-gravity coefficient, 9.8N / kg; γ-water density, 9.8kN / m 3 ;μ-viscosity coefficient of water, 2.98MPa·s;

[0024] The permeability obtained from the test of the water-proof permeability characteristics of the compacted body is converted into a permeability coefficient using the above formula, and compared with the permeability grading standard of the gangue fluidized slurry compacted body, the permeability grade of the gangue fluidized slurry compacted body can be obtained. The permeability grading standard of the gangue fluidized slurry compacted body is shown in Table 1.

[0025] Table 1 Permeability classification standard of gangue fluidized slurry compaction body

[0026]

[0027] The compacted filling bodies were reclassified according to the different parameter conditions of the four evaluation indicators, the permeability grade range of the compacted filling bodies under different indicator parameter conditions was analyzed, and the parameter standards of each indicator and its corresponding permeability grade of the compacted filling bodies were given.

[0028] Beneficial effects: This method can improve the water-proof performance of the gangue fluidized slurry compaction body, ensure that the filling material slurry is injected into the subsequent space to play a bearing and water-proof effect, and the evaluation data is closer to the on-site filling, and can be widely used in the field of filling and water-retaining mining. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 This is a flow chart of the method for evaluating the water-proof and permeability performance of the gangue fluidized slurry compaction body of the present invention;

[0030] Figure 2 Schematic diagram of permeability classification of compacted filling body in an embodiment of the present invention. DETAILED DESCRIPTION

[0031] The present invention will be further described below with reference to the accompanying drawings, equipment and embodiments.

[0032] like Figure 1 As shown, the present invention discloses a method for evaluating the water-proof and permeability performance of a gangue fluidized slurry compaction body, comprising the following steps:

[0033] 1) Based on the phenomenon that the slurry forms a compacted body and seepage occurs after the subsequent space gangue fluidized grouting filling, the influence of gangue particle size distribution, axial pressure, water pressure and cement content on the water-proof and permeable performance of the slurry after compaction is analyzed;

[0034] 2) Determine the test scheme for the water-proof and permeability performance of the compacted body of the fluidized gangue slurry: Use a filling material seepage test system, use a filling body composed of loose gangue with different particle size distributions after water saturation, consider different gangue particle size distributions, axial pressure, water pressure and cement content conditions, and test the water-proof and permeability performance of the compacted filling body; the filling material seepage test system includes a vertically arranged piston-cylinder structure, the piston-cylinder structure includes a cylinder body for accommodating a model filling body, and an axial pressure piston arranged on the top of the model filling body, wherein a seepage inlet is provided at the bottom of the cylinder body, and the piston structure A displacement sensor and a seepage outlet are arranged on it, and pressure sensors and temperature sensors are arranged at different height positions in the filling body of the cylinder body. When in use, the loading device is used to make the piston structure load a constant pressure axial stress to the model specimen in the cylinder body to the working pressure, and the gangue grouting material is injected into the cylinder body through the seepage inlet at the bottom of the cylinder body, and the readings of all pressure sensors and temperature sensors, as well as the displacement value of the displacement sensor are collected in real time, and the injection speed, cumulative injection volume and injection pressure parameters of the constant speed and constant pressure pump are collected in real time; the seepage outlet is weighed by an electronic balance to collect data in real time.

[0035] 3) Using the data obtained from the water-blocking seepage test device, the permeability changes of the gangue fluidized slurry compact under different gangue particle size distribution, axial pressure, water pressure and cement content were analyzed;

[0036] 4) Combined with the permeability evolution of the gangue fluidized slurry compacted body, a permeability grading standard for the gangue fluidized slurry compacted body is constructed, which covers four evaluation indicators: gangue particle size grading, axial pressure, water pressure and cement content. The water-proof and permeability effect of the gangue fluidized slurry compacted body is graded and evaluated. The four evaluation indicators, gangue particle size grading, axial pressure, water pressure and cement content, are used separately or in coordination as needed during the evaluation.

[0037] During the seepage process of the filling material, let p1 be the pore pressure at the seepage inlet, p2 be the pore pressure at the seepage outlet, and p2 be zero. Then the pressure gradient of the filling material at a height of h is:

[0038]

[0039] In the formula, G P is the pore pressure gradient under each level of water pressure, Pa / m; p1 is the pore pressure at the seepage inlet, Pa; p2 is the pore pressure at the seepage outlet, Pa.

[0040] The permeability k and non-Darcy factor β can be calculated according to the Forchheimer non-Darcy law formula:

[0041]

[0042] Where μ is the viscosity coefficient of the fluid, Pa·s; v is the flow velocity, m / s; k is the permeability, m 2 ρ 液 is the density of the seepage fluid, kg / m 3 ; β is the non-Darcy flow factor, m -1 .

[0043] The pressure gradient G generated by different water pressures under the same axial pressure P By fitting with the seepage velocity v, the permeability k and non-Darcy factor β can be obtained.

[0044] After the gangue slurry is filled into the subsequent space, the free water will gradually be lost due to the effects of gravity, pressure, etc. Therefore, in the seepage test, the piston cylinder structure does not need to be loaded according to the concentration of the gangue slurry. By loading loose gangue with a certain particle size distribution after saturation with water, the state of the compacted filling body can be simulated.

[0045] In order to study the influence of particle size gradation, axial pressure, water pressure and cement content on the water-proof and permeable characteristics of compacted filling bodies, the permeability of compacted filling bodies was tested by single factor control method to characterize their water-proof and permeable characteristics. Based on team research and engineering practice, the optimized particle size gradation of gangue fluidized slurry is 0-2mm and 0-5mm. The mass ratio of 0.15-2mm to 0-0.15mm gangue in 0-2mm gangue is (0-2):1, and the concentration is 60%; the mass ratio of 2-5mm, 0.15-2mm and 0-0.15mm gangue in 0-5mm gangue is (0-0.3):2:1, and the concentration is 65%; the axial pressure levels are selected as 2, 4, 6, and 8MPa, and the corresponding water pressure is selected as four levels less than the axial pressure, and the cement content is 4% and 8%. The specific test plan is shown in Table 2

[0046] Table 2 Test scheme for water-proof and permeability characteristics of compacted bodies

[0047]

[0048] The water-proof and permeability test system of gangue fluidized slurry compaction body was used to record the test results of the water-proof and permeability characteristics of the compaction body under different indicators, as shown in Table 2.

[0049] Table 2 Water-proof and permeability test results

[0050]

[0051]

[0052] Through the degree of change in permeability magnitude, it is analyzed whether the water-proof permeability characteristics of the compacted filling body remain within a stable range; the broken line relationship between different indicators and permeability is drawn to determine the growth relationship between each indicator and permeability, and a comprehensive analysis of the degree to which the permeability of the compacted filling body is affected by axial pressure, water pressure, particle size distribution and cement content shows that increasing the axial pressure of the gangue slurry, reducing the particle size range of the gangue slurry and adding cement can increase the permeability grade of the compacted filling body and improve the water-proof performance of the compacted filling body.

[0053] The permeability classification of the compacted body of gangue fluidized slurry is formulated based on the permeability coefficient, based on the porous medium characteristics of the compacted filling body, using the formula: Where: K-permeability coefficient, cm / s; ρ-density of water, g / cm 3 ; g- gravity coefficient, taken as 9.8N / kg; γ- water density, 9.8kN / m 3; μ-viscosity coefficient of water, 2.98MPa·s; The permeability and permeability coefficient are equivalently converted according to the permeability classification standard of the compacted body of gangue fluidized slurry in Table 1, and the test results of the water-proof permeability characteristics of the compacted filling body are compared. It can be seen that in most cases the permeability of the compacted filling body is slightly permeable. Therefore, 0-2mm and 0-5mm gangue slurry can meet the requirements of subsequent space grouting filling in the mine after filling.

[0054] Table 1 Permeability classification standard of gangue fluidized slurry compaction body

[0055]

[0056] Using the compacted filling body permeability classification method in Table 1, the compacted filling body is reclassified according to the different parameter conditions of the four evaluation indicators, such as Figure 2 It can be seen that the permeability levels of all groups of compacted filling bodies are within the range of micro-permeability and extremely micro-permeability, indicating that the gangue slurry can play a good water-proof effect after filling into the mining space. Figure 2 The middle curve shows that when the axial pressure of the compacted filling body exceeds 6MPa and the cement content reaches 8%, the permeability level of the compacted filling body is extremely slightly permeable. Therefore, when the particle size distribution of the gangue slurry compacted filling body is 0-5mm and the cement content is 8%, the water-proof permeability performance of the compacted body formed by the gangue slurry injected into the subsequent space is the best.

[0057] By evaluating the permeability coefficient of the compacted body of gangue fluidized slurry by graded evaluation, the influence trend of axial pressure, water pressure, particle size distribution and cement content on its permeability and water-proof performance is studied, and the optimal ratio of gangue slurry is determined to ensure the high efficiency, safety and accuracy of grouting filling.

Claims

1. A method for evaluating the water-proof and permeability performance of a compacted gangue fluidized slurry, characterized in that: The steps include: 1) Based on the phenomenon that the slurry forms a compacted body and seepage occurs after the subsequent space gangue fluidized grouting filling, the influence of gangue particle size distribution, axial pressure, water pressure and cement content on the water-proof and permeable performance of the slurry after compaction is analyzed; 2) Determine the test scheme for the water-proof and permeability performance of the compacted body of the fluidized gangue slurry: Use a filling material seepage test system, use a filling body composed of loose gangue with different particle size distributions after water saturation, consider different gangue particle size distributions, axial pressure, water pressure and cement content conditions, and test the water-proof and permeability performance of the compacted filling body; the filling material seepage test system includes a vertically arranged piston-cylinder structure, the piston-cylinder structure includes a cylinder body for accommodating a model filling body, and an axial pressure piston arranged on the top of the model filling body, wherein a seepage inlet is provided at the bottom of the cylinder body, and the piston structure A displacement sensor and a seepage outlet are arranged on it, and pressure sensors and temperature sensors are arranged at different height positions in the filling body of the cylinder body. When in use, the loading device is used to make the piston structure load a constant pressure axial stress to the model specimen in the cylinder body to the working pressure, and the gangue grouting material is injected into the cylinder body through the seepage inlet at the bottom of the cylinder body, and the readings of all pressure sensors and temperature sensors, as well as the displacement value of the displacement sensor are collected in real time, and the injection speed, cumulative injection volume and injection pressure parameters of the constant speed and constant pressure pump are collected in real time; the seepage outlet is weighed by an electronic balance to collect data in real time. 3) Using the data obtained from the water-blocking seepage test device, the permeability changes of the gangue fluidized slurry compact under different gangue particle size distribution, axial pressure, water pressure and cement content were analyzed; 4) Combined with the permeability evolution of the gangue fluidized slurry compacted body, a permeability grading standard for the gangue fluidized slurry compacted body is constructed, which covers four evaluation indicators: gangue particle size grading, axial pressure, water pressure and cement content. The water-proof and permeability effect of the gangue fluidized slurry compacted body is graded and evaluated. The four evaluation indicators, gangue particle size grading, axial pressure, water pressure and cement content, are used separately or in coordination as needed during the evaluation.

2. The method for evaluating water-proof and permeability performance of a gangue fluidized slurry compaction body according to claim 1, characterized in that: The subsequent space described in step 1) includes the delamination zone and fracture zone formed by the overlying rock strata after mining; the phenomenon of seepage of the compacted body refers to the gangue slurry being injected into the delamination zone and fracture zone in the subsequent space through the grouting drilling hole, and the excess water in the slurry is continuously lost along the cracks and voids of the rock mass, and the aggregate in the gangue slurry is gradually compacted by the gravity of the overlying rock strata, the extrusion of the rock mass and the local stress concentration.

3. The method for evaluating water-proof and permeability performance of a gangue fluidized slurry compaction body according to claim 1, characterized in that: The water-proof and permeability performance of the slurry after compaction in step 1) refers to the water-proof and permeability performance of a whole compacted filling body formed in the delamination zone and the fracture zone after the seepage phenomenon of the filling gangue slurry occurs. The compacted filling body plays a bearing and water-proof role in the delamination zone and the fracture zone; the gangue particle size grading is the main factor affecting the mechanical properties of the gangue fluidized slurry, and the permeability characteristics of the slurry after compaction change with the change of its own mechanical properties; the axial pressure simulates the scene of the compacted filling body being subjected to pressure in the overlying rock formation, thereby affecting the permeability performance of the slurry compaction body; the water pressure refers to the water pressure generated by the pressure of the overlying aquifer flowing to the compaction body through the water-conducting fracture channel, and the water-proof and permeability performance of the compaction body changes greatly under different water pressures. The cement content of different mass proportions will greatly affect the internal heterogeneous structure of the gangue fluidized slurry, and its permeability and water-proof performance will change after the gangue slurry is compacted.

4. The method for evaluating water-proof and permeability performance of a gangue fluidized slurry compaction body according to claim 1, characterized in that: Testing the water-proof and permeability performance of the compacted filling body in step 2) includes the following steps: a. Load the corresponding proportion of gangue slurry into the cylinder, scrape the surface of the material flat, make it 8cm away from the upper port of the cylinder, finally connect the pipeline and check the air tightness again; b. The axial pressure piston provides axial stress through water pressure, increases axial pressure by repeated liquid suction and injection, and prepares the compacted filling body by graded loading and pressure maintenance; c. Use a horizontal flow pump to pressurize the seepage inlet at the bottom of the cylinder. The seepage outlet pressure at the top of the axial pressure piston is 0. Adjust the inlet pressure from small to large. After the water seeps stably in the compacted filling body, turn on the permeability test switch, and simultaneously record the pressure gradient and seepage flow data, and calculate the permeability of the compacted filling body.

5. The method for evaluating water-proof and permeability performance of a gangue fluidized slurry compaction body according to claim 4, characterized in that: Gradual loading and pressure maintenance means that the target loading stress is divided into 4 levels for loading, and each level is pressure maintained for 20 minutes. When the loading stress of each level increases and the water seepage under the pressure maintenance state reaches a stable value, the compacted filling body is in a saturated state, indicating that the preparation of the filling compaction body is completed, and the subsequent water-proof and permeability performance test of the filling compaction body under the axial pressure of this level can be directly carried out; Gradual loading is a stress loading method that loads the same filling compaction body step by step, and obtains the seepage data of different factors under various levels of stress from the filling compaction body, thereby reducing the test time and cost; The test process of graded loading is as follows: ① determine the stress level values ​​of the graded loading test; ② when the stress level reaches the next stress level determined by the test plan, continue to complete the tests under this stress level and cycle in sequence to the maximum stress level determined by the test plan.

6. The method for evaluating water-proof and permeability performance of a gangue fluidized slurry compaction body according to claim 1, characterized in that: In the test scheme for the water-proof and permeability performance of the compacted gangue fluidized slurry, two particle size gradations are selected: 0-2 mm and 0-5 mm, wherein the mass ratio of 0.15-2 mm to 0-0.15 mm gangue in 0-2 mm gangue is (0-2):1, and the corresponding slurry concentration is 60%; the mass ratio of 2-5 mm, 0.15-2 mm and 0-0.15 mm gangue in 0-5 mm gangue is (0-0.3):2:1, and the corresponding slurry concentration is 65%.

7. The method for evaluating water-proof and permeability performance of a gangue fluidized slurry compaction body according to claim 1, characterized in that: The permeability evolution of the gangue fluidized slurry compaction body is obtained by drawing a line chart between different indicators and the permeability measured in the test, and comprehensively analyzing the growth relationship between each indicator and the permeability.

8. The method for evaluating water-proof and permeability performance of a gangue fluidized slurry compaction body according to claim 1, characterized in that: The permeability classification of the gangue fluidized slurry compaction body is formulated based on the permeability coefficient. Based on the porous medium characteristics of the compacted filling body, the permeability and permeability coefficient are equivalently converted. The conversion formula is: Where: K-permeability coefficient, cm / s; ρ-water density, g / cm; g-gravity coefficient, 9.8N / kg; γ-water density, 9.8kN / m 3 ;μ-viscosity coefficient of water, 2.98MPa·s; The permeability obtained from the test of the water-proof permeability characteristics of the compacted body is converted into a permeability coefficient using the above formula, and compared with the permeability grading standard of the gangue fluidized slurry compacted body, the permeability grade of the gangue fluidized slurry compacted body can be obtained. The permeability grading standard of the gangue fluidized slurry compacted body is shown in Table 1. Table 1 Permeability classification standard of gangue fluidized slurry compaction body The compacted filling bodies were reclassified according to the different parameter conditions of the four evaluation indicators, the permeability grade range of the compacted filling bodies under different indicator parameter conditions was analyzed, and the parameter standards of each indicator and its corresponding permeability grade of the compacted filling bodies were given.

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