A method and system for recreating grouting and filling space in shallowly buried weakly cemented overburden

Abstract

The present invention discloses a method and system for recreating grouting filling space of shallow-buried weakly cemented overburden, the method comprising the following steps: adopting a field measurement method combining drilling and geophysical prospecting to sort out and analyze the spatiotemporal evolution law of the overburden grouting space of the mine, and calculate the safe grouting volume; constructing a numerical model for grouting of shallow-buried weakly cemented overburden, analyzing the distribution, size and tension characteristics of cracks under different mining conditions and different overburden structures, and dividing stable areas and weak areas according to the crack development characteristics; establishing a correspondence between the amount of grouting of waste rock in the overburden injectable space and the crack characteristics of the weak area of shallow-buried weakly cemented overburden based on the above steps, analyzing the crack repair requirements of the weak area of overburden under different grouting timings and grouting amounts, and determining the overburden repair engineering parameters; comprehensively evaluating the reconstruction effect of the grouting filling space in combination with the grouting filling amount of the delamination, monitoring the new cracks and the repair effect of the original cracks in the weak area of overburden in real time, and feedback-adjusting the repair parameters of the weak area of shallow-buried weakly cemented overburden.

Description

Technical Field

[0001] The present invention relates to the technical field of grouting and filling, and in particular to a method and system for recreating grouting and filling space in shallow buried weakly cemented overburden. Background Art

[0002] Due to the impact of high-intensity mining, mining areas in western my country produce large amounts of waste rock, but lack storage facilities and face high transportation costs. Large-scale waste rock disposal has become an urgent engineering challenge in these areas. Separation layer grouting and filling technology is the best solution for large-scale waste rock disposal. This technology is theoretically mature, does not affect mining and filling, and uses simple process equipment, allowing for large waste rock disposal volumes.

[0003] However, most mines in the western mining area are shallow, weakly cemented rock formations with a short diagenesis history. These formations are characterized by numerous inter-particle pores, poor cementation, low strength, easy disintegration, and sludge formation upon contact with water. The coal seams at the working faces of the western mining area are relatively thick, causing large variations in the development and expansion of cracks in the overlying rock formations. These cracks are highly interconnected, even extending to the surface. The shallow depth of the grouting locations can easily lead to grouting pressure, which can cause grouting to break up and affect the surface environment. Therefore, to address the difficulty of grouting in shallow, weakly cemented rock formations, a method for precisely recreating grouting filling space is urgently needed, which would have extremely high engineering application value. Summary of the Invention

[0004] In response to the problems and needs raised above, this proposal proposes a method for recreating grouting and filling space in shallowly buried weakly cemented overburden. Due to the adoption of the following technical features, the above technical objectives can be achieved and many other technical effects can be brought about.

[0005] One object of the present invention is to provide a method for reconstructing grouting and filling space in shallowly buried weakly cemented overburden, comprising the following steps:

[0006] S10: Analyze the spatial evolution characteristics of grouting in shallow, weakly cemented overburden affected by mining: Using a field measurement method combining drilling and geophysical exploration, analyze the spatial and temporal evolution of overburden grouting in typical mines with different rock structures and mining intensities, and calculate the safe grouting volume;

[0007] S20: Determine weak areas of shallow-buried weakly cemented overburden affected by mining: Construct a numerical model for grouting in shallow-buried weakly cemented overburden, analyze the distribution, size, and tension characteristics of cracks under different mining conditions and overburden structures, and divide stable and weak areas based on the crack development characteristics;

[0008] S30: Determine shallow buried weakly cemented overburden repair parameters based on the amount of waste rock disposal: Based on steps S10 and S20, establish a correspondence between the amount of waste rock grouting in the overburden available space and the crack characteristics of the shallow buried weakly cemented overburden, analyze the crack repair requirements of the weak overburden under different grouting timings and grouting amounts, and determine the overburden repair engineering parameters;

[0009] S40: Evaluation and feedback of grouting filling space reconstruction effect: Combined with the grouting filling volume of the separation layer, the grouting filling space reconstruction effect is comprehensively evaluated, and the new cracks and the repair effect of the original cracks in the weak overburden area are monitored in real time, and feedback is provided to adjust the repair parameters of the shallow buried weakly cemented overburden weak area.

[0010] In this technical solution, the grouting filling method blocks the through cracks from the delamination area to the ground, accurately recreates the grouting filling space, solves the problem of ground slurry leakage during delamination grouting in shallow, weakly cemented rock formations in the west, protects the ground ecological environment and shallow surface water resources, and is conducive to achieving the goals of large-scale processing of western waste rock, safe and efficient mining of coal resources, and ecological and environmental protection. This method is logically reasonable, highly applicable, simple to operate, and effective, and has wide application value.

[0011] In addition, the method for reconstructing grouting and filling space in shallowly buried weakly cemented overburden according to the present invention may also have the following technical features:

[0012] In one example of the present invention, in step S10, the safe grouting volume calculation formula is as follows:

[0013]

[0014] Where: W is the height of the cavity space determined by geophysical exploration; L is the advancing length of the working face; d is the width of the working face.

[0015] In one example of the present invention, in step S20, the weak areas include: areas where through cracks appear in shallowly buried weakly cemented overburden rock due to mining, and rock formations where grouting filling is prone to leakage.

[0016] In one example of the present invention, in step S30, the overburden repair engineering parameters include: rapid gelling slurry ratio, rapid gelling slurry grouting position and rapid gelling slurry grouting volume.

[0017] In one example of the present invention, the rapid gelling slurry is made by mixing gangue, fly ash, cement, expansive agent and accelerator, wherein the gangue particle size is less than 1 mm, the admixture amount is 70-90%, the cement admixture amount is 6-10%, the expansive agent admixture amount is 1-3%, and the accelerator admixture amount is 2-3% of the cement amount.

[0018] In one example of the present invention, the grouting position of the rapid gelling slurry refers to above the through-fissure in the weak area of the shallowly buried weakly cemented overburden.

[0019] In one example of the present invention, in step S40, the evaluation of the grouting filling space reconstruction effect includes the following steps: real-time monitoring of the separation layer grouting orifice pressure and grouting volume, if the orifice pressure rises rapidly, stop grouting; if the orifice pressure remains stable, continue grouting.

[0020] In one example of the present invention, if the orifice pressure remains stable, the method further comprises:

[0021] When judging whether the grouting volume exceeds the preset value, if the grouting volume exceeds the preset value, drilling is used to determine whether slurry leakage occurs. If slurry leakage occurs, injection is continued. If slurry leakage is found, the separation grouting is stopped and grouting is resumed after the rock formation in the leakage area is repaired.

[0022] Another object of the present invention is to provide a shallow buried weakly cemented overburden reconstruction grouting filling system, comprising:

[0023] The grouting volume calculation module is configured to analyze the spatial evolution characteristics of shallow, weakly cemented overburden affected by mining. Using a combination of drilling and geophysical survey methods, the module analyzes the spatial and temporal evolution of overburden grouting in typical mines with different rock structures and mining intensities, and calculates the safe grouting volume.

[0024] The module for dividing the fracture development areas is configured to determine the weak areas of shallow-buried weakly cemented overburden affected by mining. This module constructs a numerical model for grouting in shallow-buried weakly cemented overburden, analyzes the fracture distribution, size, and tension characteristics under different mining conditions and overburden structures, and divides the fracture development characteristics into stable and weak areas.

[0025] The repair engineering parameter calculation module is configured to determine the repair parameters of shallow-buried weakly cemented overburden based on the amount of waste rock disposed: based on the grouting volume calculation module and the crack development area division module, a corresponding relationship is established between the waste rock grouting volume of the overburden available space and the crack characteristics of the weak area of the shallow-buried weakly cemented overburden. The crack repair requirements of the weak area of the overburden under different grouting timing and grouting volume are analyzed to determine the overburden repair engineering parameters;

[0026] The reconstruction effect evaluation and feedback module is configured to evaluate and provide feedback on the reconstruction effect of grouting filling space: combined with the grouting filling volume of the separation layer, the reconstruction effect of the grouting filling space is comprehensively evaluated, the new cracks and the repair effect of the original cracks in the weak overburden area are monitored in real time, and the feedback is used to adjust the repair parameters of the shallow buried weakly cemented overburden weak area.

[0027] In one example of the present invention, in the grouting volume calculation module, the safe grouting volume calculation formula is as follows:

[0028]

[0029] Where: W is the height of the cavity space determined by geophysical exploration; L is the advancing length of the working face; d is the width of the working face.

[0030] Hereinafter, the best embodiment of the present invention will be described in more detail with reference to the accompanying drawings so that the features and advantages of the present invention can be easily understood. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings of the embodiments of the present invention. The drawings are only used to illustrate some embodiments of the present invention, but not to limit all embodiments of the present invention thereto.

[0032] Figure 1 This is a flow chart of a method for accurately recreating separation layer grouting and filling space in shallow buried weakly cemented rock strata according to an embodiment of the present invention;

[0033] Figure 2 For numerical simulation of the crack expansion and development characteristics and slurry flow path of the overburden according to an embodiment of the present invention;

[0034] Figure 3 Schematic diagram of crack propagation in shallow-buried weakly cemented rock formations affected by mining according to an embodiment of the present invention;

[0035] Figure 4 Schematic diagram of grouting and filling space for precise reconstruction of delamination in shallow-buried weakly cemented rock strata according to an embodiment of the present invention.

[0036] List of reference numerals:

[0037] No through cracks 10;

[0038] 20 cracks have been penetrated;

[0039] Grouting filling space 30;

[0040] Rapid gelling slurry 40;

[0041] Fissure sealing drilling 50. DETAILED DESCRIPTION

[0042] In order to make the purpose, technical solution and advantages of the technical solution of the present invention clearer, the technical solution of the embodiment of the present invention will be clearly and completely described below in conjunction with the drawings of specific embodiments of the present invention. The same figure marks in the drawings represent the same parts. It should be noted that the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the described embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0043] Unless otherwise defined, the technical or scientific terms used herein shall have the ordinary meaning understood by persons of ordinary skill in the field to which the invention belongs. The words "first", "second" and similar terms used in the patent application specification and claims of the present invention do not indicate any order, quantity or importance, but are only used to distinguish different components. Similarly, words such as "a" or "an" do not necessarily indicate a quantity limitation. Words such as "include" or "comprising" mean that the elements or objects preceding the word include the elements or objects listed after the word and their equivalents, without excluding other elements or objects. Words such as "connected" or "connected" are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the object being described changes, the relative positional relationship may also change accordingly.

[0044] According to the first aspect of the present invention, a method for reconstructing grouting and filling space in shallow buried weakly cemented overburden is provided. Figure 1 As shown, the following steps are included:

[0045] S10: Analyze the spatial evolution characteristics of grouting in shallow, weakly cemented overburden affected by mining: Using a field measurement method combining drilling and geophysical exploration, analyze the spatial and temporal evolution of overburden grouting in typical mines with different rock structures and mining intensities, and calculate the safe grouting volume;

[0046] S20: Determine weak areas of shallow-buried weakly cemented overburden affected by mining: Construct a numerical model for grouting in shallow-buried weakly cemented overburden, analyze the distribution, size, and tension characteristics of cracks under different mining conditions and overburden structures, and divide stable and weak areas based on the crack development characteristics;

[0047] S30: Determine shallow buried weakly cemented overburden repair parameters based on the amount of waste rock disposal: Based on steps S10 and S20, establish a correspondence between the amount of waste rock grouting in the overburden available space and the crack characteristics of the shallow buried weakly cemented overburden, analyze the crack repair requirements of the weak overburden under different grouting timings and grouting amounts, and determine the overburden repair engineering parameters;

[0048] S40: Evaluation and feedback of grouting filling space reconstruction effect: Combined with the grouting filling volume of the separation layer, the grouting filling space reconstruction effect is comprehensively evaluated, and the new cracks and the repair effect of the original cracks in the weak overburden area are monitored in real time, and feedback is provided to adjust the repair parameters of the shallow buried weakly cemented overburden weak area.

[0049] This grouting filling method blocks the through cracks from the delamination area to the ground, accurately recreates the grouting filling space, solves the problem of grouting leakage during delamination grouting in shallow, weakly cemented rock formations in the west, protects the ground ecological environment and shallow surface water resources, and is conducive to achieving the goals of large-scale treatment of waste rock in the west, safe and efficient mining of coal resources, and ecological and environmental protection. This method has reasonable logic, strong applicability, simple operation, obvious effect, and has wide application value.

[0050] In one example of the present invention, in step S10, the safe grouting volume calculation formula is as follows:

[0051]

[0052] Where: W is the height of the cavity space determined by geophysical exploration; L is the advancing length of the working face; d is the width of the working face.

[0053] In one example of the present invention, in step S20, the weak areas include: areas where through cracks appear in shallowly buried weakly cemented overburden rock due to mining, and rock formations where grouting filling is prone to leakage.

[0054] In one example of the present invention, in step S30, the overburden repair engineering parameters include: rapid gelling slurry ratio, rapid gelling slurry grouting position and rapid gelling slurry grouting volume.

[0055] In one example of the present invention, the rapid gelling slurry is made by mixing gangue, fly ash, cement, expansive agent and accelerator, wherein the gangue particle size is less than 1 mm, the admixture amount is 70-90%, the cement admixture amount is 6-10%, the expansive agent admixture amount is 1-3%, and the accelerator admixture amount is 2-3% of the cement amount.

[0056] In one example of the present invention, the grouting position of the rapid gelling slurry refers to above the through-fissure in the weak area of the shallowly buried weakly cemented overburden.

[0057] In one example of the present invention, in step S40, the evaluation of the grouting filling space reconstruction effect includes the following steps: real-time monitoring of the separation layer grouting orifice pressure and grouting volume, if the orifice pressure rises rapidly, stop grouting; if the orifice pressure remains stable, continue grouting.

[0058] In one example of the present invention, if the orifice pressure remains stable, the method further comprises:

[0059] When judging whether the grouting volume exceeds the preset value, if the grouting volume exceeds the preset value, drilling is used to determine whether slurry leakage occurs. If slurry leakage occurs, injection is continued. If slurry leakage is found, the separation grouting is stopped and grouting is resumed after the rock formation in the leakage area is repaired.

[0060] According to the second aspect of the present invention, a shallow buried weakly cemented overburden reconstruction grouting filling system comprises:

[0061] The grouting volume calculation module is configured to analyze the spatial evolution characteristics of shallow, weakly cemented overburden affected by mining. Using a combination of drilling and geophysical survey methods, the module analyzes the spatial and temporal evolution of overburden grouting in typical mines with different rock structures and mining intensities, and calculates the safe grouting volume.

[0062] The module for dividing the fracture development areas is configured to determine the weak areas of shallow-buried weakly cemented overburden affected by mining. This module constructs a numerical model for grouting in shallow-buried weakly cemented overburden, analyzes the fracture distribution, size, and tension characteristics under different mining conditions and overburden structures, and divides the fracture development characteristics into stable and weak areas.

[0063] The repair engineering parameter calculation module is configured to determine the repair parameters of shallow-buried weakly cemented overburden based on the amount of waste rock disposed: based on the grouting volume calculation module and the crack development area division module, a corresponding relationship is established between the waste rock grouting volume of the overburden available space and the crack characteristics of the weak area of the shallow-buried weakly cemented overburden. The crack repair requirements of the weak area of the overburden under different grouting timing and grouting volume are analyzed to determine the overburden repair engineering parameters;

[0064] The reconstruction effect evaluation and feedback module is configured to evaluate and provide feedback on the reconstruction effect of grouting filling space: combined with the grouting filling volume of the separation layer, the reconstruction effect of the grouting filling space is comprehensively evaluated, the new cracks and the repair effect of the original cracks in the weak overburden area are monitored in real time, and the feedback is used to adjust the repair parameters of the shallow buried weakly cemented overburden weak area.

[0065] In one example of the present invention, in the grouting volume calculation module, the safe grouting volume calculation formula is as follows:

[0066]

[0067] Where: W is the height of the cavity space determined by geophysical exploration; L is the advancing length of the working face; d is the width of the working face.

[0068] Specific cases

[0069] Taking a mine as an example, the specific implementation steps are as follows:

[0070] S10: According to the investigation, the 81202 working face of a certain mine is buried 200m deep, with an average coal thickness of 6.02m, a working face advance length of 2484m, and a width of 240m. High-density electrical method (geophysical method) was used to test and analyze the resistivity changes of the overburden profile above the working face. Combined with the drilling results, the location and size of the rock stratum cavity area were determined. The cavity space height W is 1.64m. The safe grouting volume calculated by formula 1 is 1.0238 million m 3.

[0071] S20: Standard specimens were made from cores of the overlying strata at the working face. The compressive strength, Poisson's ratio, and density were tested. Parameter calibration was performed using numerical simulation. The calibration results are shown in Table 1. A fracture development model for shallow-buried weakly cemented rock formations was constructed. The overlying strata with unpenetrated fractures (10) and penetrated fractures (20) under the mining conditions of the working face were shown in Figure 1. Figure 2 By changing different parameters such as working face width, advancement length, mining thickness, and overburden structure, the corresponding fracture development distribution and morphology are given.

[0072] Table 1 Calibration results of overburden parameters of numerical model

[0073]

[0074]

[0075] S30: Based on the distribution and expansion characteristics of the cracks in the above model, determine the grouting filling space 30, change the grouting time, grouting position, and grouting amount of the separation layer, and determine that the grouting amount of the separation layer is higher than 950,000 m 3 The overburden control effect is better, so based on the grouting volume of 950,000 m 3 The parameters of the reconstruction filling space engineering were determined based on the development of the overlying rock cracks at that time: ① The ratio of the fast-setting slurry 40 is 87% of the waste rock, 10% of the cement, 3% of the expansion agent, and 3% of the quick-setting agent, with a mass concentration of 72%; ② The injection volume of the fast-setting slurry 40 is the total volume of the through-cracks in the rock layer above the separation layer, which is about 35,000 m 3 The location of the crack plugging borehole 50 is the through crack above the stratum. The crack distribution of the shallow buried weakly cemented overburden after mining is as follows: Figure 3 As shown, the filling space reconstruction method is shown as follows Figure 4 shown.

[0076] S40: Real-time monitoring of the orifice pressure and grouting volume of the separation layer grouting. If the orifice pressure rises rapidly, grouting is stopped, indicating that the grouting filling space reconstruction effect is good. If the orifice pressure remains stable but the grouting volume exceeds the preset value, drilling is used to determine whether grouting has occurred. If grouting has not occurred, grouting is continued. If grouting is found, separation layer grouting is stopped and grouting is resumed after the rock formation in the grouting area is repaired. This method is used to reconstruct the grouting filling space and then grouting is carried out. A total of 14 separation layer grouting boreholes were constructed, with the maximum grouting volume of a single hole being 91,000 m 3 There is no slurry leakage or slurry emergence on the surface, and the rock stratum repair effect is good.

[0077] This overburden reconstruction grouting filling space method aims to solve the problem that grouting easily leaks to the surface during grouting in shallow, weakly cemented rock formations in the west. It proposes a method and system for sealing the through-going cracks from the delamination area to the ground and accurately recreating the grouting filling space. It uses a method combined with field measurement and numerical simulation to accurately determine the correspondence between the delamination grouting volume and the crack characteristics of the weak overburden area, designs key parameters for overburden restoration, protects the ground ecological environment and shallow surface water resources, and at the same time ensures sufficient grouting volume in the delamination area and controls the stability of the overburden, which is conducive to achieving the goals of large-scale treatment of waste rock in the west and safe and efficient mining of coal resources. This method has reasonable logic, strong applicability, simple operation, obvious effect, and has wide application value.

[0078] The exemplary implementation of the method for reconstructing grouting and filling space of shallow buried weakly cemented overburden proposed by the present invention is described in detail above with reference to the preferred embodiments. However, it can be understood by those skilled in the art that, without departing from the concept of the present invention, various modifications and variations can be made to the above-mentioned specific embodiments, and various technical features and structures proposed by the present invention can be combined in various ways without exceeding the scope of protection of the present invention, which is determined by the appended claims.

Claims

1. A method for reconstructing grouting and filling space in shallowly buried weakly cemented overburden, characterized in that: The steps include: S10: Analyze the spatial evolution characteristics of grouting in shallow, weakly cemented overburden affected by mining: Using a field measurement method combining drilling and geophysical exploration, analyze the spatial and temporal evolution of overburden grouting in typical mines with different rock structures and mining intensities, and calculate the safe grouting volume; S20: Determine weak areas of shallow-buried weakly cemented overburden affected by mining: Construct a numerical model for grouting in delamination of shallow-buried weakly cemented overburden, analyze the distribution, size, and tension characteristics of cracks under different mining conditions and different overburden structures, and divide the areas into stable and weak areas based on the crack development characteristics. The weak areas include: areas of shallow-buried weakly cemented overburden affected by mining, where through-cracks appear, and areas of rock strata where grouting during delamination is prone to slurry leakage. S30: Determine the shallow buried weak cemented overburden repair parameters based on the amount of gangue disposal: Based on steps S10 and S20, establish the corresponding relationship between the amount of gangue grouting in the overburden injectable space and the crack characteristics of the shallow buried weak cemented overburden, analyze the crack repair needs of the weak overburden under different grouting timing and grouting amount, and determine the overburden repair engineering parameters; the overburden repair engineering parameters include: rapid gelling slurry ratio, rapid gelling slurry grouting position and rapid gelling slurry grouting amount; the rapid gelling slurry is a mixture of gangue, fly ash, cement, expansive agent and accelerator, wherein the gangue particle size is less than 1 mm, the amount of cement is 70-90%, the amount of cement is 6-10%, the amount of expansive agent is 1-3%, and the amount of accelerator is 2-3% of the cement amount; the grouting amount of rapid gelling slurry is the total volume of the through-going cracks in the rock layer above the separation layer, which is about 35,000 m 3 The grouting position of the rapid gelling slurry is above the through-fissure in the weak area of the shallowly buried weakly cemented overburden rock; S40: Evaluation and feedback on the effect of grouting filling space reconstruction: The through cracks from the delamination area to the ground are sealed, and the grouting filling space is accurately recreated. Combined with the grouting filling volume of the delamination, the effect of grouting filling space reconstruction is comprehensively evaluated. The new cracks and the repair effect of the original cracks in the weak overburden area are monitored in real time, and feedback is provided to adjust the repair parameters of the shallow buried weakly cemented overburden weak area.

2. The method for reconstructing grouting and filling space in shallow buried weakly cemented overburden according to claim 1 is characterized in that: In step S10, the safe grouting volume calculation formula is as follows: Where: W The height of the void space determined by geophysical exploration; L is the advancing length of the working face; d is the working surface width.

3. The method for reconstructing grouting and filling space in shallow buried weakly cemented overburden according to claim 1 is characterized in that: In step S40, the evaluation of the grouting filling space reconstruction effect includes the following steps: real-time monitoring of the separation layer grouting orifice pressure and grouting volume, if the orifice pressure rises rapidly, stop grouting; if the orifice pressure remains stable, continue grouting.

4. The method for reconstructing grouting and filling space in shallow buried weakly cemented overburden according to claim 3 is characterized in that: If the orifice pressure remains stable, it also includes: When judging whether the grouting volume exceeds the preset value, if the grouting volume exceeds the preset value, drilling is used to determine whether slurry leakage occurs. If slurry leakage occurs, injection is continued. If slurry leakage is found, the separation grouting is stopped and grouting is resumed after the rock formation in the leakage area is repaired.

5. A shallow buried weakly cemented overburden reconstruction grouting filling system, characterized in that: include: The grouting volume calculation module is configured to analyze the spatial evolution characteristics of shallow, weakly cemented overburden affected by mining. Using a combination of drilling and geophysical survey methods, the module analyzes the spatial and temporal evolution of overburden grouting in typical mines with different rock structures and mining intensities, and calculates the safe grouting volume. The module for dividing fracture development areas is configured to determine weak areas of shallow-buried weakly cemented overburden affected by mining. The module constructs a numerical model for grouting separation in shallow-buried weakly cemented overburden, analyzes the distribution, size, and tension characteristics of fractures under different mining conditions and overburden structures, and divides stable areas into weak areas based on fracture development characteristics. The weak areas include areas of shallow-buried weakly cemented overburden affected by mining, where through fractures appear, and areas of rock strata where grouting separation filling is prone to slurry leakage. The repair engineering parameter calculation module is configured to determine the repair parameters of shallow-buried weakly cemented overburden based on the amount of gangue disposal: based on the grouting volume calculation module and the crack development area division module, the corresponding relationship between the gangue grouting volume of the overburden available space and the crack characteristics of the weak area of the shallow-buried weakly cemented overburden is established, the crack repair requirements of the weak area of the overburden under different grouting timings and grouting volumes are analyzed, and the overburden repair engineering parameters are determined; the overburden repair engineering parameters include: rapid gelling slurry ratio, rapid gelling slurry grouting position and rapid gelling slurry grouting volume; the rapid gelling slurry is a mixture of gangue, fly ash, cement, expansive agent and accelerator, wherein the gangue particle size is less than 1 mm, the admixture is 70-90%, the cement admixture is 6-10%, the expansive agent admixture is 1-3%, and the accelerator admixture is 2-3% of the cement amount; the grouting volume of the rapid gelling slurry is the total volume of the through-going cracks in the rock layer above the separation layer, which is about 35,000 m 3 The grouting position of the rapid gelling slurry is above the through-fissure in the weak area of the shallowly buried weakly cemented overburden rock; The reconstruction effect evaluation and feedback module is configured to evaluate and provide feedback on the reconstruction effect of grouting filling space: it blocks the through cracks from the delamination area to the ground, accurately recreates the grouting filling space, comprehensively evaluates the reconstruction effect of the grouting filling space based on the delamination grouting filling volume, monitors the repair effect of new cracks and original cracks in weak overburden areas in real time, and provides feedback to adjust the repair parameters of shallow buried weakly cemented overburden weak areas.

6. The shallow buried weakly cemented overburden reconstruction grouting filling system according to claim 5 is characterized in that: In the grouting volume calculation module, the safe grouting volume calculation formula is as follows: Where: W The height of the void space determined by geophysical exploration; L is the advancing length of the working face; d is the working surface width.

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