Method and system for reconstructing grouting filling space by shallow-buried weakly-cemented overlying strata

Abstract

The invention discloses a method and a system for reconstructing a grouting filling space by shallow-buried weakly-cemented overlying strata, and the method comprises the following steps: arranging and analyzing an overlying strata grouting space spatio-temporal evolution law of a mine by adopting an actual measurement method combining drilling and geophysical prospecting, and calculating a safe grouting volume; constructing a shallow-buried weakly-cemented overlying strata separation layer grouting numerical model, analyzing fracture distribution, size and tension characteristics of different mining working conditions and different overlying strata structures, and dividing a stable area and a weak area according to fracture development characteristics; on the basis of the above steps, the corresponding relation between the overlying strata groutable space gangue grouting amount and the shallow-buried weakly-cemented overlying strata weak area crack characteristics is established, the overlying strata weak area crack repairing requirements under the conditions of different grouting opportunities and grouting amounts are analyzed, and overlying strata repairing engineering parameters are determined; and comprehensively evaluating the reconstruction effect of the grouting filling space by combining the separation layer grouting filling amount, monitoring the repair effect of new cracks and original cracks in the weak area of the overlying strata in real time, and feeding back and adjusting repair parameters of the weak area of the shallow-buried weakly-cemented overlying strata.

Description

Technical Field

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

[0002] Due to the high-intensity mining, the mining areas in western my country have a large amount of gangue production, no storage sites, and high transportation costs. Large-scale disposal of gangue has become an engineering problem that needs to be solved urgently in the western mining areas. Separation layer grouting filling technology is the best solution for large-scale disposal of gangue. The technology is mature in theory, mining and filling do not affect each other, the process equipment is simple, and the amount of gangue disposal is large.

[0003] However, most of the mines in the western mining area are shallowly buried weakly cemented rock formations with a short diagenesis time. They have many inter-particle pores, poor cementation, low strength, easy disintegration, and easy mudification when exposed to water. The coal seams at the working face of the western mining area are relatively thick, resulting in large variations in the development and expansion of the cracks in the overlying rock formations, and a wide range of changes. The cracks between the rock formations are highly connected and even extend to the surface. The grouting position is shallowly buried, and under the influence of the grouting pressure, it is easy to cause grouting on the ground, affecting the ground environment. Therefore, in order to solve the problem of difficult grouting in shallowly buried weakly cemented rock formations, it is urgent to propose a method for accurately recreating grouting filling space, which has extremely high engineering application value. Summary of the invention

[0004] In response to the problems and needs raised above, this solution proposes a method for recreating grouting 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 rock, comprising the following steps:

[0006] S10: Analyze the spatial evolution characteristics of shallow-buried weakly cemented overburden affected by mining: Use a combination of drilling and geophysical exploration to 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 the 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 the stable area and weak area according to the crack development characteristics;

[0008] S30: Determine shallow buried weakly cemented overburden repair parameters based on the amount of gangue disposal: Based on steps S10 and S20, establish a corresponding relationship between the amount of gangue grouting in the overburden space that can be injected and the crack characteristics of the weak area of ​​the shallow buried weakly cemented overburden, analyze the crack repair requirements of the weak area of ​​the 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, 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 adjusted to adjust the repair parameters of the shallow buried weakly cemented overburden weak area.

[0010] In this technical scheme, 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 buried weakly cemented rock strata 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 gangue, safe and efficient mining of coal resources, and ecological environmental protection. This method has reasonable logic, strong applicability, simple operation, obvious effect, and has wide application value.

[0011] In addition, the method for reconstructing grouting and filling space of shallow 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 advancement length of the working face; d is the width of the working face.

[0015] In an example of the present invention, in step S20, the weak area includes: a rock formation area where through cracks appear in shallowly buried weakly cemented overburden rock due to mining, and a rock formation area where grouting is easy to leak during delamination grouting.

[0016] In one example of the present invention, in the 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 setting slurry is mixed with gangue, fly ash, cement, expansive agent and accelerator, wherein the gangue particle size is less than 1 mm, the dosage is 70-90%, the cement dosage is 6-10%, the expansive agent dosage is 1-3%, and the accelerator dosage is 2-3% of the cement dosage.

[0018] In one example of the present invention, the grouting position of the rapid gelling slurry refers to above the through-cracks 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 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 delamination grouting is stopped and grouting is continued 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-buried weakly cemented overburden affected by mining: using a combination of drilling and geophysical exploration to analyze the temporal and spatial evolution of overburden grouting in typical mines with different rock structures and different mining intensities, and calculate the safe grouting volume;

[0024] The fracture development area division module is configured to determine the weak areas of shallow buried weakly cemented overburden affected by mining: construct a numerical model of grouting in shallow buried weakly cemented overburden, analyze the fracture distribution, size and tension characteristics of different mining conditions and different overburden structures, and divide the stable area and weak area according to the fracture development characteristics;

[0025] The repair engineering parameter calculation module is configured to determine the repair parameters of the shallow-buried weakly-cemented overburden based on the amount of gangue disposal: based on the grouting volume calculation module and the fracture development area division module, the corresponding relationship between the gangue grouting volume of the overburden available space and the fracture characteristics of the weak area of ​​the shallow-buried weakly-cemented overburden is established, the fracture 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;

[0026] The reconstruction effect evaluation and feedback module is configured to evaluate and feedback the reconstruction effect of grouting filling space: combined with the grouting filling volume of the separation layer, comprehensively evaluate the reconstruction effect of the grouting filling space, monitor the new cracks and the repair effect of the original cracks in the weak overburden area in real time, and feedback 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 advancement length of the working face; d is the width of the working face.

[0030] The best embodiment for carrying out the present invention will be described in more detail below 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, wherein 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 To numerically simulate the crack expansion and development characteristics and slurry running path of the overburden according to an embodiment of the present invention;

[0034] Figure 3 A schematic diagram of crack expansion under the influence of mining in a shallow-buried weakly cemented rock formation according to an embodiment of the present invention;

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

[0036] List of reference numerals:

[0037] Unpenetrated cracks 10;

[0038] 20 cracks have been penetrated;

[0039] Grouting filling space 30;

[0040] Rapid gelling slurry 40;

[0041] Fracture plugging 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 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 terms or scientific terms used herein shall have the usual meanings understood by persons of ordinary skill in the field to which the present invention belongs. The words "first", "second" and similar words 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 "one" or "one" do not necessarily indicate a quantity limitation. Words such as "include" or "comprise" mean that the elements or objects appearing before the word include the elements or objects listed after the word and their equivalents, without excluding other elements or objects. Words such as "connect" 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 described object 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, as follows: Figure 1 As shown, the following steps are included:

[0045] S10: Analyze the spatial evolution characteristics of shallow-buried weakly cemented overburden affected by mining: Use a combination of drilling and geophysical exploration to 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 the 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 the stable area and weak area according to the crack development characteristics;

[0047] S30: Determine shallow buried weakly cemented overburden repair parameters based on the amount of gangue disposal: Based on steps S10 and S20, establish a corresponding relationship between the amount of gangue grouting in the overburden space that can be injected and the crack characteristics of the weak area of ​​the shallow buried weakly cemented overburden, analyze the crack repair requirements of the weak area of ​​the 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, 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 adjusted 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 ground slurry leakage during delamination grouting in shallow buried weakly cemented rock strata 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 western gangue, safe and efficient mining of coal resources, and ecological 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 advancement length of the working face; d is the width of the working face.

[0053] In an example of the present invention, in step S20, the weak area includes: a rock formation area where through cracks appear in shallowly buried weakly cemented overburden rock due to mining, and a rock formation area where grouting is easy to leak during delamination grouting.

[0054] In one example of the present invention, in the 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 setting slurry is mixed with gangue, fly ash, cement, expansive agent and accelerator, wherein the gangue particle size is less than 1 mm, the dosage is 70-90%, the cement dosage is 6-10%, the expansive agent dosage is 1-3%, and the accelerator dosage is 2-3% of the cement dosage.

[0056] In one example of the present invention, the grouting position of the rapid gelling slurry refers to above the through-cracks 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 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 delamination grouting is stopped and grouting is continued after the rock formation in the leakage area is repaired.

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

[0061] The grouting volume calculation module is configured to analyze the spatial evolution characteristics of shallow-buried weakly cemented overburden affected by mining: using a combination of drilling and geophysical exploration to analyze the temporal and spatial evolution of overburden grouting in typical mines with different rock structures and different mining intensities, and calculate the safe grouting volume;

[0062] The fracture development area division module is configured to determine the weak areas of shallow buried weakly cemented overburden affected by mining: construct a numerical model of grouting in shallow buried weakly cemented overburden, analyze the fracture distribution, size and tension characteristics of different mining conditions and different overburden structures, and divide the stable area and weak area according to the fracture development characteristics;

[0063] The repair engineering parameter calculation module is configured to determine the repair parameters of the shallow-buried weakly-cemented overburden based on the amount of gangue disposal: based on the grouting volume calculation module and the fracture development area division module, the corresponding relationship between the gangue grouting volume of the overburden available space and the fracture characteristics of the weak area of ​​the shallow-buried weakly-cemented overburden is established, the fracture 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;

[0064] The reconstruction effect evaluation and feedback module is configured to evaluate and feedback the reconstruction effect of grouting filling space: combined with the grouting filling volume of the separation layer, comprehensively evaluate the reconstruction effect of the grouting filling space, monitor the new cracks and the repair effect of the original cracks in the weak overburden area in real time, and feedback 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 advancement length of the working face; d is the width of the working face.

[0068] Specific examples

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

[0070] S10: According to the survey, the 81202 working face of a certain mine is buried 200m deep, with an average coal thickness of 6.02m, a working face advancement length of 2484m, and a width of 240m. The high-density electrical method (geophysical method) is 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 are 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: The core of the overlying rock layer on the working face was made into a standard specimen, and its compressive strength, Poisson's ratio and density were tested. The parameters were calibrated by numerical simulation. The parameter calibration results are shown in Table 1. A fracture development model of shallow buried weakly cemented rock formation was constructed. The overlying rock formation with unpenetrated fractures 10 and penetrated fractures 20 under the mining conditions of the working face was shown in Figure 1. Figure 2 By changing different parameters such as working face width, advancement length, mining thickness, overburden structure, etc., 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 and filling space engineering were determined based on the development of the overlying rock cracks at that time: ① The proportion of the fast-setting slurry 40 was 87% of the gangue, 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 was the total volume of the through-cracks in the rock above the separation layer, about 35,000 m 3 The location of the crack plugging borehole 50 is the through crack above the separation layer. The distribution of cracks in 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 grouting. If the orifice pressure rises rapidly, the 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 slurry is leaking. If not, continue to fill. If slurry is found, stop the separation grouting and wait until the rock formation in the leakage area is repaired before continuing the grouting. This method is used to reconstruct the grouting filling space and then perform grouting. A total of 14 separation grouting boreholes were constructed, and the maximum grouting volume of a single hole was 91,000 m 3 There is no slurry leakage or bubbling 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 grout easily leaks to the surface during grouting in shallow buried weakly cemented rock strata in the west. It proposes a method and system for sealing the through cracks from the delamination area to the ground and accurately reconstructing the grouting filling space. It adopts the method of combining actual measurement with numerical simulation to accurately determine the corresponding relationship between the delamination grouting volume and the crack characteristics in the weak overburden area, designs the key parameters of overburden restoration, protects the ecological environment and shallow surface water resources on the ground, and can ensure sufficient grouting volume in the delamination area and control the stability of the overburden, which is conducive to the large-scale treatment of western gangue and safe and efficient mining of coal resources. This method has reasonable logic, strong applicability, simple operation, obvious effect, and wide application value.

[0078] The exemplary implementation of the method for reconstructing grouting and filling space in shallow buried weakly cemented overburden rock proposed in the present invention is described in detail above with reference to the preferred embodiments. However, those skilled in the art will appreciate 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 in the present invention can be combined in various ways without exceeding the protection scope 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 rock, characterized in that: The steps include: S10: Analyze the spatial evolution characteristics of shallow-buried weakly cemented overburden affected by mining: Use a combination of drilling and geophysical exploration to 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 the 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 the stable area and weak area according to the crack development characteristics; S30: Determine shallow buried weakly cemented overburden repair parameters based on the amount of gangue disposal: Based on steps S10 and S20, establish a corresponding relationship between the amount of gangue grouting in the overburden space that can be injected and the crack characteristics of the weak area of ​​the shallow buried weakly cemented overburden, analyze the crack repair requirements of the weak area of ​​the overburden under different grouting timings and grouting amounts, and determine the overburden repair engineering parameters; 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, 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 adjusted 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 is the height of the cavity space determined by geophysical exploration; L is the advancement length of the working face; d is the width of the working face.

3. The method for reconstructing grouting and filling space in shallowly buried weakly cemented overburden according to claim 1 is characterized in that: In step S20, the weak areas include: shallowly buried weakly cemented overburden rock with through cracks due to mining, and rock formation areas where grouting is easy to leak during separation grouting.

4. The method for reconstructing grouting and filling space in shallowly buried weakly cemented overburden according to claim 1 is characterized in that: In the step S30, the overburden repair engineering parameters include: the ratio of the rapid gelling slurry, the grouting position of the rapid gelling slurry and the grouting amount of the rapid gelling slurry.

5. The method for reconstructing grouting and filling space in shallowly buried weakly cemented overburden according to claim 4 is characterized in that: The fast-setting slurry is mixed with gangue, fly ash, cement, expansion agent and accelerator, wherein the gangue particle size is less than 1 mm, the mixing amount is 70-90%, the cement mixing amount is 6-10%, the expansion agent mixing amount is 1-3%, and the accelerator mixing amount is 2-3% of the cement dosage.

6. The method for reconstructing grouting and filling space in shallow buried weakly cemented overburden according to claim 4 is characterized in that: The grouting position of the rapid gelling slurry refers to the top of the through-cracks in the weak area of ​​the shallowly buried weakly cemented overburden rock.

7. The method for reconstructing grouting and filling space in shallowly buried weakly cemented overburden according to claim 1 is characterized in that: In step S40, the evaluation of the effect of grouting filling space reconstruction 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.

8. The method for reconstructing grouting and filling space in shallowly buried weakly cemented overburden according to claim 7 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 delamination grouting is stopped and grouting is continued after the rock formation in the leakage area is repaired.

9. 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-buried weakly cemented overburden affected by mining: using a combination of drilling and geophysical exploration to analyze the temporal and spatial evolution of overburden grouting in typical mines with different rock structures and different mining intensities, and calculate the safe grouting volume; The fracture development area division module is configured to determine the weak areas of shallow buried weakly cemented overburden affected by mining: construct a numerical model of grouting in shallow buried weakly cemented overburden, analyze the fracture distribution, size and tension characteristics of different mining conditions and different overburden structures, and divide the stable area and weak area according to the fracture development characteristics; The repair engineering parameter calculation module is configured to determine the repair parameters of the shallow-buried weakly-cemented overburden based on the amount of gangue disposal: based on the grouting volume calculation module and the fracture development area division module, the corresponding relationship between the gangue grouting volume of the overburden available space and the fracture characteristics of the weak area of ​​the shallow-buried weakly-cemented overburden is established, the fracture 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 reconstruction effect evaluation and feedback module is configured to evaluate and feedback the reconstruction effect of grouting filling space: combined with the grouting filling volume of the separation layer, comprehensively evaluate the reconstruction effect of the grouting filling space, monitor the new cracks and the repair effect of the original cracks in the weak overburden area in real time, and feedback to adjust the repair parameters of the shallow buried weakly cemented overburden weak area.

10. The shallow buried weakly cemented overburden reconstruction grouting filling system according to claim 9 is characterized in that: In the grouting volume calculation module, the safe grouting volume calculation formula is as follows: Where: W is the height of the cavity space determined by geophysical exploration; L is the advancement length of the working face; d is the width of the working face.

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