A method for preventing grouting and bursting of geological structures under mining by grouting and filling

Abstract

The present invention discloses a method for preventing slurry collapse in geological structure management under delamination grouting and filling mining, which belongs to the technical field of coal mine filling mining. The method comprises the following steps: determining the distribution morphology of the hidden structure: injecting high-pressure water into the delamination area, and simultaneously using geophysical prospecting and drilling methods to obtain the distribution morphology of non-bonded or weakly bonded hidden structures in the stratum; determining the anti-slurry collapse grouting area; determining the grouting treatment plan according to the burial depth of the coal seam and the development of the hidden structure; and testing the grouting reinforcement effect. The present invention can not only effectively prevent slurry collapse accidents caused by the flow of slurry through the hidden structure, but also determine the hidden structure grouting reinforcement area through theoretical calculation. Compared with grouting reinforcement of the entire hidden structure, it can effectively reduce costs and enhance the targeting of grouting reinforcement treatment in the hidden structure area.

Description

Technical Field

[0001] The invention relates to the technical field of coal mine filling mining, and in particular to a method for preventing slurry collapse in geological structure management under separation layer grouting filling mining. Background Art

[0002] Separation grouting is a technical method for controlling surface subsidence and movement. Its basic principle is to inject high-pressure grouting into the separation layer of the overburden, using slurry to fill the separation space, support the overburden, and block the transmission of mining motion, thereby controlling the overburden and surface movement. When geological structures exist within the strata, such as non-cohesive or weakly cohesive hidden structures in the overburden of the working face, the grouting separation layer can connect with the coal mining face, causing slurry failure and threatening production at the working face.

[0003] Among the existing patents, CN201910990300.1 - A method for preventing and controlling grouting during delamination grouting, which conducts tracer tests to determine the flow pattern of the tracer in the water-conducting structure, and determines the grouting location through theoretical calculation, thereby achieving precise prevention and control of grouting. CN202311201953.X - A method for determining the position and pressure of delamination grouting, which obtains the actual grouting pressure and the pressure that the delamination space can withstand through theoretical calculation, and then determines the position of the key grouting layer and the grouting layer section. When the grouting layer and grouting pressure are feasible, delamination grouting is implemented, thereby improving the quality of the project and the level of safety assurance, and preventing underground grouting accidents. CN202311136823.2 - A method for reducing settlement by precise grouting of composite curtains of overburden and multiple delamination layers of overburden, which reinforces the cracks or weak surfaces by injecting cement slurry into multiple thick hard rock layers in the cracks or weak surfaces of geological structures, and forming a multi-layer protective curtain on the top of the grouting layer to prevent grouting and slurry leakage during delamination grouting. CN202410723293.X - A method for sealing through-fissures by grouting in a delamination layer and a microcapsule specifically used for the method, which determines whether there are fissures in the delamination space based on the change in pressure during the delamination grouting process, injects a slurry containing microcapsules into the delamination layer to seal the through-fissures, and uses microcapsules to timely seal the fissures at the leakage points. The above patent solves the problems of slurry burst and slurry leakage during delamination grouting by theoretical analysis, curtain construction or the addition of new sealing materials. When there are geological structures in the stratum, such as when there are non-bonded or weakly bonded hidden structures in the overburden of the working face, if the mining area is not sealed, the slurry will move along the non-bonded or weakly bonded hidden structures, which will not only affect the delamination grouting effect, but also cause the grouting delamination to be connected to the coal mining working face, causing slurry burst accidents and threatening the safe production of the working face. Summary of the Invention

[0004] In order to solve the technical problems existing in the above-mentioned prior art, the present invention provides a method for preventing slurry collapse in geological structure management under delamination grouting filling mining. The constructed combined sealing dam body can effectively prevent the slurry from flowing and migrating to the remaining space of the target delamination above the mined area during delamination grouting under unilateral open conditions, thereby enhancing the delamination grouting effect.

[0005] To achieve the above object, the present invention provides the following technical solution: a method for preventing slurry collapse in geological structures under mining by grouting and filling in a delamination layer, comprising the following steps:

[0006] S1. Determine the distribution of concealed structures: By injecting high-pressure water into the detached layer, geophysical prospecting and drilling methods are used to determine the distribution of non-cohesive or weakly cohesive concealed structures in the stratum.

[0007] S2. Determine the anti-collapse grouting area;

[0008] S3. Determine the grouting treatment plan based on the coal seam burial depth and the development of the concealed structure in S1. The grouting treatment plan includes: above-ground grouting treatment, underground grouting treatment, and above-ground and underground combined grouting treatment;

[0009] S4. Test the grouting reinforcement effect: Carry out high-pressure water injection experiment again through the delamination grouting drilling hole, inspect it through geophysical exploration method, and observe whether there is water dripping or leakage on the coal mining working face; if water dripping occurs on the coal mining working face, stop the high-pressure water injection immediately, determine the leakage location based on the geophysical exploration results, and seal it by injecting slurry prepared by cement, plugging agent and quick-setting material through the grouting reinforcement drilling hole until there is no water dripping or leakage on the working face.

[0010] Preferably, in S1, high-pressure water injection is carried out into the delamination area through the surface delamination grouting drilling holes of the coal mining working face. Under the action of pressure, water flows along the hidden structure. At the same time, geophysical methods are used to detect non-bonded or weakly bonded hidden structures in the stratum, and drilling methods are used for auxiliary detection, and finally the distribution morphology of the non-bonded or weakly bonded hidden structures in the stratum is obtained.

[0011] Preferably, in S2, the grouting separation layer is first determined in the longitudinal direction, and then the area between the upper part of the water-conducting fracture zone and the grouting separation layer is determined as the longitudinal grouting area.

[0012] Combined with the distribution of the concealed structure obtained in S1, the scope of the grouting area along the advancing direction and the dip direction of the working face is determined.

[0013] Preferably, the distance from the grouting separation layer to the coal seam is greater than the sum of the height of the water-conducting fracture zone and the height of the isolation maintenance zone, and the calculation formula is:

[0014] H 离 ≥H 导 +(5~8)M

[0015] Where H 离 is the height of the detached layer, m; H 导 is the height of the water-conducting fracture zone determined by the properties of the overburden, m; M is the height of the coal seam, m.

[0016] Preferably, the calculation formula for the length of the grouting reinforcement area along the advancing direction of the working face is:

[0017]

[0018] Where, L 横 is the length of the grouting reinforcement area along the advancing direction of the working face, m; H is the distance from the water-conducting fracture zone to the stratum, m; α is the dip angle of the hidden structure along the advancing direction of the working face, °; L0 is the width of the grouting reinforcement protection zone, m.

[0019] The calculation formula for the length of the grouting reinforcement area along the inclination direction of the working face is:

[0020]

[0021] Where, L 倾 is the length of the grouting reinforcement area along the working face dip direction, β is the dip angle of the hidden structure along the working face dip direction, °.

[0022] The width of the grouting reinforcement protection zone is determined by the leading influence distance, and its calculation formula is:

[0023] L0=H0cotω

[0024] Where L0 is the width of the grouting reinforcement protection zone, m; H0 is the average mining depth, m; ω is the leading influence angle, degrees.

[0025] Preferably, in S3, the grouting treatment scheme is divided into above-hole grouting treatment, below-hole grouting treatment and above-hole and below-hole combined grouting treatment.

[0026] When the coal seam is buried below 600 meters, the surface grouting treatment scheme is adopted; when the coal seam is buried above 600 meters, the underground grouting treatment scheme is adopted; when the non-bonded or weakly bonded concealed structure develops highly close to the surface in the vertical direction and the span developed in the direction of the working face exceeds the width of the working face, the surface and underground combined grouting treatment is adopted.

[0027] Preferably, the above-ground grouting treatment scheme specifically includes: grouting the hidden structure of the surface of the coal mining face at intervals of L j Construct multiple rows of stepped grouting reinforcement holes along the working face advancing direction to the grouting reinforcement area, construct the middle hole to the bottom of the grouting reinforcement area, inject slurry prepared by cement, plugging agent and quick-setting material to seal the hidden structure; the remaining grouting reinforcement holes are spaced L apart. jThe holes are arranged in a stepped manner on the left and right sides, with the end hole positions spaced at a height of h0. Slurry prepared with cement and plugging agent is injected into the grouting reinforcement area in sequence until the grouting reinforcement of the anti-collapse grouting area is completed.

[0028] Preferably, the underground grouting treatment specifically includes: dividing the grouting reinforcement area into three different height layers in the longitudinal direction, and spacing L in the tunnel on one side of the working face. j Construct multiple groups of directional drilling holes to different layers, and inject slurry prepared by cement, plugging agent and quick-setting material into the grouting reinforcement area through the directional drilling hole in the lowest layer to seal the hidden structure; inject slurry prepared by cement and plugging agent into the grouting reinforcement area through the directional drilling holes in the remaining layers until the grouting reinforcement of the anti-collapse grouting area is completed.

[0029] Preferably, the above-ground and underground combined grouting treatment specifically includes: extending the delamination grouting borehole in the grouting reinforcement area to the bottom of the grouting reinforcement area, and constructing a directional drilling hole in the tunnel on one side of the working face to the same layer, and injecting slurry prepared by cement, plugging agent and quick-setting material into the bottom of the grouting reinforcement area through the delamination grouting borehole and the directional drilling hole to seal the hidden structure; after the sealing is completed, the delamination grouting borehole is re-drilled for secondary hole expansion, and then the delamination grouting borehole is lifted upward by a certain distance h1, and the slurry prepared by cement and plugging agent is injected, and then it is lifted again by a certain distance h1 until the anti-collapse grouting area is completely reinforced.

[0030] Preferably, in S3, the slurry prepared from cement and plugging agent has a ratio of cement: plugging agent = 7:2;

[0031] In S3 and S4, the slurry prepared from cement, plugging agent and quick-setting material has a ratio of cement: plugging agent: quick-setting material = 7:1:2;

[0032] The water-cement ratio is 1:0.46.

[0033] Compared with the prior art, the present invention provides a method for preventing slurry collapse in geological structures under mining by grouting and filling in the delamination layer, which has the following beneficial effects:

[0034] (1) A variety of schemes were proposed to treat non-bonded or weakly bonded hidden structures (grouting and reinforcement drilling and grouting treatment in surface construction, directional drilling and grouting treatment in underground construction, and combined grouting treatment in surface and underground). These schemes provide a variety of options for the treatment of hidden structures, can effectively block the hidden structure area, block the passage between the grouting separation layer and the coal mining face, and ensure the smooth grouting and filling of the separation layer of the coal mining face. During actual construction, the final grouting treatment scheme is determined by comprehensively considering factors such as geological mining conditions and construction costs, so as to achieve effective treatment of non-bonded or weakly bonded hidden structures in the stratum.

[0035] (2) The grouting reinforcement slurry proposed in the present invention is prepared from cement, plugging agent and quick-setting material. Compared with ordinary cement slurry, it has higher viscosity and shorter setting time. After injection, the slurry can be concentrated near the grouting reinforcement area and can effectively seal the hidden structure area.

[0036] (3) The present invention determines the grouting reinforcement area of ​​the hidden structure through theoretical calculation. Compared with grouting reinforcement of the entire hidden structure, it can effectively reduce costs and enhance the targeting of grouting reinforcement management in the hidden structure area. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

[0038] Figure 1 A flow chart of a method for preventing slurry collapse in geological structures under stratum grouting and filling mining proposed in an embodiment of the present invention;

[0039] Figure 2 Schematic diagram of the distribution of grouting separation layers in an embodiment of the present invention;

[0040] Figure 3 Schematic diagram of the distribution of grouting reinforcement areas along the advancing direction of the working face in an embodiment of the present invention;

[0041] Figure 4 Schematic diagram of the grouting reinforcement area along the inclination direction of the working face in an embodiment of the present invention;

[0042] Figure 5 Schematic diagram of grouting treatment in the well along the advancing direction of the working face in an embodiment of the present invention;

[0043] Figure 6 A top view of a ground drilling according to an embodiment of the present invention;

[0044] Figure 7 Schematic diagram of downhole grouting treatment along the inclination direction of the working face in an embodiment of the present invention;

[0045] Figure 8 This is a top view of the downhole grouting treatment along the advancing direction of the working face in an embodiment of the present invention;

[0046] Figure 9 Schematic diagram of above- and below-ground combined grouting treatment along the advancing direction of the working face in an embodiment of the present invention;

[0047] Figure 10 Schematic diagram of above- and below-ground combined grouting treatment along the working face inclination direction according to an embodiment of the present invention;

[0048] Figure 11It is a schematic diagram of uphole grouting in the uphole and downhole combined grouting treatment process in an embodiment of the present invention. DETAILED DESCRIPTION

[0049] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. The components of the embodiments of the present invention generally described and shown in the drawings herein can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the claimed invention, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without making creative work fall within the scope of protection of the present invention.

[0050] This embodiment proposes a method for preventing slurry from collapsing in geological structures under stratum grouting and filling mining. The detailed steps are as follows: Figures 1 to 11 As shown:

[0051] (1) Determine the distribution of hidden structures

[0052] High-pressure water injection is carried out into the delamination area through grouting holes on the surface of the coal mining face. In order to prevent accidents such as well flooding during the high-pressure water injection experiment, plugging agents are added to the water to reduce the fluidity of the water. Under the action of pressure, the water will flow along the hidden structure. At the same time, survey lines are laid on the surface above the coal mining face, in the tunnels on both sides of the working face, and in the open cuts. Geophysical methods such as transient electromagnetic are used to detect non-cohesive or weakly cohesive hidden structures in the stratum, and drilling methods are used for auxiliary detection to obtain the distribution morphology of non-cohesive or weakly cohesive hidden structures in the stratum.

[0053] (2) Determine the anti-collapse grouting area

[0054] 1) Determine the grouting separation layer. The distance from the grouting separation layer to the coal seam should be greater than the sum of the height of the water-conducting fracture zone and the height of the isolation maintenance zone (5 to 8 times the mining height). The calculation formula is:

[0055] H 离 ≥H 导 +(5~8)M

[0056] Where H 离 is the height of the detached layer, m; H 导 is the height of the water-conducting fracture zone determined by the properties of the overburden, m; M is the height of the coal seam, m.

[0057] 2) Determine the height of the grouting reinforcement area in the longitudinal direction. Based on the determined grouting layer position of the separation layer and combined with the distribution of the hidden structure determined in step 1, the area above the water-conducting fracture zone to the grouting separation layer is determined as the longitudinal grouting reinforcement area.

[0058] 3) Determine the length of the grouting reinforcement area along the working face advancement direction based on the distribution of the hidden structure detected in step 1.

[0059]

[0060] Where, L 横 is the length of the grouting reinforcement area along the advancing direction of the working face, m; H is the distance from the water-conducting fracture zone to the stratum, m; α is the dip angle of the hidden structure along the advancing direction of the working face, °; L0 is the width of the grouting reinforcement protection zone, m.

[0061] Length of grouting reinforcement area along the inclination direction of the working face:

[0062]

[0063] Where, L 倾 is the length of the grouting reinforcement area along the working face dip direction, β is the dip angle of the hidden structure along the working face dip direction, °.

[0064] The width of the grouting reinforcement protection zone is determined by the leading influence distance, and its calculation formula is:

[0065] L0=H0cotω

[0066] Where L0 is the width of the grouting reinforcement protection zone, m; H0 is the average mining depth, m; ω is the leading influence angle, degrees.

[0067] (3) Carry out multi-scheme grouting treatment

[0068] The spacing between grouting holes in the separation layer is determined by the diffusion radius of the fly ash slurry. The calculation formula for the distance between adjacent grouting holes in the separation layer is:

[0069] L a ≤2kl 粉

[0070] Where, L a is the distance between adjacent separation layer grouting holes, m; k is the safety factor, which is 0.3 to 0.7; l 粉 is the diffusion radius of fly ash slurry, m

[0071] The calculation formula for the distance between adjacent grouting reinforcement boreholes is:

[0072] L j ≤2kl

[0073] Where, L jis the distance between adjacent grouting reinforcement boreholes, m; k is the safety factor, ranging from 0.3 to 0.7; l is the diffusion radius of the slurry prepared from cement and plugging agent, m. The spacing between each group of directional drilling holes is the same as the spacing between grouting reinforcement boreholes.

[0074] Solution 1: grouting treatment on the well, grouting area of ​​hidden structure on the surface of coal mining working face at intervals of L j Construct multiple rows of stepped grouting reinforcement holes along the working face advancing direction to the grouting reinforcement area, and construct the middle hole to the bottom of the grouting reinforcement area. By injecting slurry prepared by cement, plugging agent and quick-setting material to seal the non-bonded or weakly bonded hidden structure, the channel between the grouting separation layer and the coal mining working face is blocked. The plugging agent can increase the viscosity of the cement slurry, and the quick-setting material can accelerate the solidification of the cement slurry. The remaining grouting reinforcement holes are spaced L apart. j The holes are arranged in a stepped manner on the left and right sides, with the end hole positions spaced at a height of h0. After the grouting of the bottom area is completed, slurry prepared by cement and plugging agent is injected into the grouting reinforcement area in sequence through the grouting reinforcement holes on both sides until the grouting reinforcement of the anti-collapse grouting area is completed.

[0075] Solution 2: Underground grouting treatment, the grouting reinforcement area is divided into three different height layers in the vertical direction, and the grouting reinforcement area is divided into three different height layers in the tunnel on one side of the working face. j Construct multiple groups of directional drilling holes to different layers of the grouting reinforcement area. The grouting casing of the directional drilling holes in the grouting reinforcement area is a flower pipe. Slurry prepared by cement, plugging agent and quick-setting material is injected into the grouting reinforcement area through the directional drilling holes in the lowest layer. The plugging agent can increase the viscosity of the cement slurry, and the quick-setting material can accelerate the solidification of the cement slurry. After the slurry is injected, it can quickly enter the cracks in the hidden structure area, which can effectively seal the non-bonded or weakly bonded hidden structure and block the channel between the grouting delamination layer and the coal mining working face. Then, the slurry prepared by cement and plugging agent is injected into the grouting reinforcement area through the directional drilling holes in the remaining layers until the grouting reinforcement of the anti-collapse grouting area is completed.

[0076] Option 3: Combined grouting treatment above and below ground. The separation layer grouting borehole in the grouting reinforcement area is extended to the bottom of the grouting reinforcement area. Simultaneously, a directional borehole is constructed in the roadway on one side of the working face to the same layer. The grouting casing in the directional borehole in the grouting reinforcement area is a flower pipe. A slurry composed of cement, a plugging agent, and a quick-setting material is injected simultaneously into the bottom of the grouting reinforcement area through the separation layer grouting borehole and the directional borehole. The plugging agent increases the viscosity of the cement slurry, and the quick-setting material accelerates the setting of the cement slurry. Once injected, the slurry quickly penetrates the fissures in the hidden structure area, effectively sealing non-bonded or weakly bonded hidden structures and blocking the passage between the grouting separation layer and the coal mining face. After sealing, the separation layer grouting borehole is re-drilled and re-enlarged. The separation layer grouting borehole is then raised a certain distance h1, and a slurry composed of cement and a plugging agent is injected. The slurry is then raised again a certain distance h1, and slurry injection continues until the anti-collapse grouting area is completely reinforced.

[0077] When the above three plans are implemented, when the coal seam is shallow, that is, the coal seam is buried at a depth of less than 600 meters, the control method of plan one can be adopted; when the coal seam is deep, that is, the coal seam is buried at a depth of more than 600 meters, the control method of plan two can be adopted; if the non-cohesive or weakly cohesive concealed structure has a large development space and a wide impact range, that is, the non-cohesive or weakly cohesive concealed structure develops highly close to the surface in the vertical direction and the span in the dip direction of the working face exceeds the width of the working face, the control method of plan three can be adopted.

[0078] (4) Test the effect of grouting reinforcement

[0079] After steps (1) to (3) are completed, the grouting reinforcement effect is tested in the following manner:

[0080] High-pressure water injection experiments are carried out through delamination grouting drilling, and inspections are carried out through geophysical methods. At the same time, the coal mining working face is observed to see if there is any water dripping or leakage. If water dripping occurs on the coal mining working face, the high-pressure water injection is stopped immediately, and the leakage location is determined based on the geophysical results. The grouting reinforcement drilling is used to inject slurry prepared with cement, plugging agent and quick-setting material to seal the leakage. The high-pressure water injection experiment and injection and sealing are repeated until there is no water dripping or leakage on the working face.

[0081] In addition, it should be noted that the slurry prepared from cement, plugging agent and quick-setting material mentioned above has a ratio of cement: plugging agent: quick-setting material = 7:1:2; the slurry prepared from cement and plugging agent has a ratio of cement: plugging agent = 7:2, and the water-cement ratio is 1:0.46.

[0082] In the description of the present invention, it should be noted that, unless otherwise specified or limited, the terms "connected" and "connection" should be understood in a broad sense. For example, it can mean a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood in specific circumstances. In addition, in the description of the present invention, unless otherwise specified, "plurality" means two or more.

[0083] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to the embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the claims and their equivalents.

Claims

1. A method for preventing slurry collapse in geological structures under mining by grouting and filling in the separation layer, characterized in that: The following steps are involved: S1. Determine the distribution of concealed structures: By injecting high-pressure water into the detached layer, geophysical exploration and drilling methods are used to determine the distribution of non-cohesive or weakly cohesive concealed structures in the stratum. Specifically, high-pressure water is injected into the stratum through grouting holes on the surface of the coal mining face. Under the action of pressure, water flows along the concealed structure. At the same time, geophysical methods are used to detect the non-cohesive or weakly cohesive concealed structures in the stratum, and drilling methods are used for auxiliary detection. Ultimately, the distribution of the non-cohesive or weakly cohesive concealed structures in the stratum is obtained. S2. Determine the anti-collapse grouting area: first determine the grouting separation layer in the longitudinal direction, and then determine the area between the upper part of the water-conducting fracture zone and the grouting separation layer as the longitudinal grouting area; Combined with the distribution of the hidden structure obtained in S1, the scope of the grouting area along the advancing direction and the dip direction of the working face is determined; S3. Determine the grouting treatment plan based on the coal seam burial depth and the development of the concealed structure in S1. The grouting treatment plan includes: above-ground grouting treatment, underground grouting treatment, and above-ground and underground combined grouting treatment; When the coal seam is buried below 600 meters, the surface grouting treatment scheme is adopted; when the coal seam is buried above 600 meters, the underground grouting treatment scheme is adopted; when the non-bonded or weakly bonded concealed structure is developed vertically close to the surface and the span in the direction of the working face is greater than the width of the working face, the surface and underground combined grouting treatment scheme is adopted; The above-ground grouting treatment plan specifically includes: grouting the hidden structure on the surface of the coal mining face at intervals of L j Construct multiple rows of stepped grouting reinforcement holes along the working face advancing direction to the grouting reinforcement area, construct the middle hole to the bottom of the grouting reinforcement area, inject slurry prepared by cement, plugging agent and quick-setting material to seal the hidden structure; the remaining grouting reinforcement holes are spaced L apart. j The holes are arranged in a stepped manner on the left and right sides, with the end holes spaced at a height of h0, and slurry prepared with cement and plugging agent is injected into the grouting reinforcement area in sequence until the grouting reinforcement of the anti-collapse grouting area is completed; The specific underground grouting treatment includes: dividing the grouting reinforcement area into three different height layers in the longitudinal direction, and j Construct multiple sets of directional drilling holes to different layers. Through the directional drilling holes in the lowest layer, inject slurry made of cement, plugging agent and quick-setting material into the grouting reinforcement area to seal the hidden structure. Through the directional drilling holes in the remaining layers, inject slurry made of cement and plugging agent into the grouting reinforcement area until the grouting reinforcement of the anti-collapse grouting area is completed. The above-ground and underground combined grouting treatment specifically includes: extending the separation layer grouting borehole in the grouting reinforcement area to the bottom of the grouting reinforcement area, and simultaneously constructing a directional drilling hole in the roadway on one side of the working face to the same layer. Through the separation layer grouting borehole and the directional drilling, a slurry prepared by cement, a plugging agent and a quick-setting material is injected into the bottom of the grouting reinforcement area to seal the hidden structure; after the sealing is completed, the separation layer grouting borehole is re-drilled for secondary hole expansion, and then the separation layer grouting borehole is lifted upward by a certain distance h1, and a slurry prepared by cement and a plugging agent is injected, and then it is lifted again by a certain distance h1 until the anti-collapse grouting area is completely reinforced; S4. Test the grouting reinforcement effect: Carry out high-pressure water injection experiment again through the delamination grouting drilling hole, inspect it through geophysical exploration method, and observe whether there is water dripping or leakage on the coal mining working face; if water dripping occurs on the coal mining working face, stop the high-pressure water injection immediately, determine the leakage location based on the geophysical exploration results, and seal it by injecting slurry prepared by cement, plugging agent and quick-setting material through the grouting reinforcement drilling hole until there is no water dripping or leakage on the working face.

2. The method for preventing slurry collapse in geological structure management under separation layer grouting and filling mining according to claim 1 is characterized in that: The distance from the grouting layer to the coal seam is greater than the sum of the height of the water-conducting fracture zone and the height of the isolation maintenance zone. The calculation formula is: H 离 ≥H 导 +(5~8)M Where H 离 is the height of the detached layer, m; H 导 is the height of the water-conducting fracture zone determined by the properties of the overburden, m; M is the height of the coal seam, m.

3. The method for preventing slurry collapse in geological structure management under delamination grouting and filling mining according to claim 2 is characterized in that: The calculation formula for the length of the grouting reinforcement area along the advancing direction of the working face is: Where, L 横 is the length of the grouting reinforcement area along the advancing direction of the working face, m; H is the distance from the water-conducting fracture zone to the stratum, m; α is the dip angle of the hidden structure along the advancing direction of the working face, °; L0 is the width of the grouting reinforcement protection zone, m; The calculation formula for the length of the grouting reinforcement area along the inclination direction of the working face is: Where, L 倾 is the length of the grouting reinforcement area along the working face dip direction, β is the dip angle of the hidden structure along the working face dip direction, °; The width of the grouting reinforcement protection zone is determined by the leading influence distance, and its calculation formula is: L0=H0cotω Where L0 is the width of the grouting reinforcement protection zone, m; H0 is the average mining depth, m; ω is the leading influence angle, degrees.

4. The method for preventing slurry collapse in geological structure management under separation layer grouting and filling mining according to claim 1 is characterized in that: In S3, the slurry prepared from cement and plugging agent has a ratio of cement: plugging agent = 7:2; In S3 and S4, the slurry prepared from cement, plugging agent and quick-setting material has a ratio of cement: plugging agent: quick-setting material = 7:1:2; The water-cement ratio is 1:0.46.

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