Filling entry retaining method and device

Abstract

The invention relates to the technical field of filling entry retaining, and discloses a filling entry retaining method and device. The filling entry retaining method comprises the steps that a filling area is defined on the side, close to the gob-side entry retaining, of the gob according to the preset width; filling materials are injected into the filling area to form a filling body for supporting the top plate of the goaf. The bearing load of the top plate on the side, close to the gob-side entry retaining side, of the gob is maximum, severe sinking and fracture deformation are most likely to happen, the filling area with the preset width is defined on the side, close to the gob-side entry retaining side, of the gob, a filling body is formed, the top plate of the gob can be stably supported, and the sinking and fracture deformation degree of the top plate is reduced; meanwhile, the gob-side entry retaining and the goaf can be separated through the filling body, the situation that the gob-side entry retaining is fractured and deformed due to the fact that stress of a goaf top plate extends to the gob-side entry retaining is avoided, and the integrity and safety of the gob-side entry retaining are guaranteed; and the filling area reduces the demand of filling materials, reduces cost and time consumption, and improves the mining efficiency of the working face.

Description

Technical Field

[0001] This invention relates to the field of backfilling and retaining technology, and specifically to a backfilling and retaining method and apparatus. Background Technology

[0002] During coal mining, as the coal face advances, a goaf is formed behind it. Backfilling mining technology addresses the ground subsidence caused by coal mining. This technology involves introducing backfill materials made from coal mine solid waste into the goaf. These materials replace the ore removed during mining, providing support to the goaf. This method not only handles coal mine solid waste but also reduces surface damage caused by ground subsidence.

[0003] The existing backfilling mining method involves using a paste backfilling support to enclose the edge of the goaf to separate the goaf from the roadway, and injecting paste-like backfilling material into the goaf to prevent the subsidence and movement of the roof strata. After the paste-like backfilling material solidifies, mining of the working face can continue.

[0004] However, existing backfilling mining methods require completely filling the goaf with paste-like backfill material, which requires a large amount of backfill material, takes a long time, and is costly, thus restricting the mining efficiency of the working face. Summary of the Invention

[0005] The purpose of this invention is to overcome the problems of existing backfilling mining methods, which require the goaf to be completely filled with paste-like backfill material, which has a large demand for backfill material, is time-consuming and costly, and restricts the mining efficiency of the working face. This invention provides a backfilling and roadway retention method and device.

[0006] To achieve the above objectives, the present invention provides a method for backfilling and retaining roadways, the method comprising: enclosing a backfilling area of ​​a predetermined width on one side of the goaf near the roadway; and injecting backfilling material into the backfilling area to form a backfill body supporting the roof of the goaf.

[0007] In some embodiments, the filling and retaining method includes determining the range of the preset width: the preset width is It can be calculated using the following formula. Scope (one); in, The width of the passageway left along the goaf; The horizontal distance from the rotation base point of the main roof to the coal face; For the pressure of the top plate; The volume force is the direct impact force. Coal seam thickness; The final strength of the filling material; The initial strength of the filling material is taken as 1 / 10. ; The elastic modulus of the filling body; The elastic modulus of the direct top of the filling region; The elastic modulus of the direct bottom of the filling region; The direct top thickness of the filling area; The direct bottom thickness of the filling area; This refers to the distance between the top and bottom of the ceiling. The length of the key block at the top; is the rock fragmentation coefficient.

[0008] In some embodiments, the filling and retaining method includes determining a preset width within the range of a above. Multiple hydraulic supports are spaced apart along the width of the filling area on the side of the goaf near the working face to support the roof of the goaf on the side near the working face. The preset width of the filling area is determined by the following formula 2. , (two); in, , The width of the hydraulic support; The number of hydraulic supports. The average width between two adjacent hydraulic supports.

[0009] In some embodiments, the filling and retaining method includes: verifying the preset width through numerical simulation experiments. The rationality of it.

[0010] In some embodiments, the numerical simulation verification method includes: in the numerical simulation experiment, according to a preset width Determine the fracture status of the top plate of the filling area. If the top plate of the filling area fractures, readjustment is performed. To recalculate until the preset width This prevents the top plate of the filling area from cracking.

[0011] In some embodiments, the filling and retaining method includes: determining the strength of the filling material.

[0012] In some embodiments, the method for determining the strength of the backfill is as follows: in the early stage of mining, the load on the roof of the gob-side retainer is determined based on one cycle of pressure, and the one-day strength of the backfill is greater than the load on the roof of the gob-side retainer; in the later stage of mining, the backfill is able to support the roof of the gob-side retainer without fracture.

[0013] Another aspect of the present invention provides a backfilling and retaining device for implementing any of the above-described backfilling and retaining methods. The backfilling and retaining device includes two rock-blocking supports, which are spaced apart on both sides of the backfilling area along its width direction. Together with the roof of the goaf, the floor of the goaf, and the rock strata behind the goaf, the backfilling area is formed. The front end of the backfilling area along the mining direction has an injection port for injecting the backfilling material.

[0014] In some embodiments, the backfilling and retaining device further includes a traction support for traction of the rock-blocking support along the mining direction; and / or the backfilling and retaining device includes a backfilling assembly for injecting the backfilling material into the backfilling area.

[0015] In some embodiments, the traction support is a hydraulic support and is used to support the roof of the goaf on the side near the working face; and / or the filling assembly includes: a filling material storage container disposed on the ground and used to store the filling material; and a delivery pipeline connecting the filling material storage container and the filling area.

[0016] In some embodiments, the filling and retaining device further includes a fixing member for fixing the delivery pipeline to the goaf retaining area; and / or the filling and retaining device further includes a buffer member disposed at the bottom of the delivery pipeline.

[0017] In some embodiments, the strength of the filling material forming the filling body is less than the strength of the rock strata in the roof and floor of the goaf-retaining tunnel.

[0018] The inventors of this invention discovered through research that the roof of a goaf near the goaf retainer bears the greatest load and is most prone to severe subsidence and fracture deformation. Constructing a pre-defined filling zone and forming a filling body on the side of the goaf near the goaf retainer can stably support the roof of the goaf, reducing the degree of roof subsidence and fracture deformation. Simultaneously, the filling body located at the boundary between the goaf retainer and the goaf can separate the goaf retainer and the goaf, preventing the stress of the goaf roof from extending to the goaf retainer and causing fracture deformation in the goaf retainer due to the influence of the goaf roof. This effectively improves the stress environment of the goaf retainer roof, transferring the stress of the goaf roof to the deeper parts of the goaf, ensuring the integrity and safety of the goaf retainer. Furthermore, the filling zone does not require filling the entire goaf, reducing the amount of filling material needed, lowering costs, reducing the time required for filling material injection and filling body formation, improving the mining efficiency of the working face, and the implementation process is simple. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the filling and retaining device disclosed in this invention.

[0020] Explanation of reference numerals in the attached figures 1. Working face; 2. Goaf; 3. Goaf roadway; 4. Filling area; 5. Filling body; 6. Rock retaining support; 7. Hydraulic support; 8. Traction support; 9. Filling material storage container; 10. Conveying pipeline. Detailed Implementation

[0021] The specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0022] In this invention, unless otherwise stated, directional terms such as "front and back" generally refer to the front and back along the mining direction of the working face, where the mining direction refers to... Figure 1 The direction indicated by the middle arrow, the width direction refers to Figure 1 The direction indicated by the middle arrow.

[0023] See Figure 1 The present invention provides a method for filling and retaining roadways, which includes: setting up a filling area 4 with a preset width on one side of the goaf 2 near the goaf retention roadway 3; and injecting filling material into the filling area 4 to form a filling body 5 that supports the roof of the goaf 2.

[0024] The inventors of this invention discovered through research that the roof of the goaf 2, near the goaf retainer 3, bears the greatest load and is most prone to severe subsidence and fracture deformation. By constructing a filling area 4 of a predetermined width and forming a filling body 5 on the side of the goaf 2 near the goaf retainer 3, the roof of the goaf 2 can be stably supported, reducing the degree of roof subsidence and fracture deformation. Simultaneously, the filling body 5, located at the boundary between the goaf retainer 3 and the goaf 2, can separate the goaf retainer 3 and the goaf 2, preventing further goafing. The stress of the roof of Zone 2 extends to the goaf retainer 3, causing the goaf retainer 3 to fracture and deform due to the influence of the roof of Zone 2. This effectively improves the stress environment of the roof of the goaf retainer 3, allowing the stress of the roof of Zone 2 to transfer to the deeper part of Zone 2, ensuring the integrity and safety of the goaf retainer 3. Furthermore, the setting of the filling zone 4 does not require filling the entire goaf 2, reducing the amount of filling material required, lowering costs, reducing the time required for filling material injection and forming the filling body 5, improving the mining efficiency of the working face 1, and the implementation process is simple.

[0025] The aforementioned backfilling and roadway retention method is particularly suitable for overhead mining faces.

[0026] Alternatively, the backfill material can be a paste-like material prepared by mixing coal gangue, fly ash, gasification slag, and mine water in a specific ratio. Using coal gangue, fly ash, and gasification slag as backfill material reduces the cost of backfilling and roadway retention, and decreases the disposal steps and costs of coal mine solid waste.

[0027] In some implementations, the filling and retaining method includes determining a range of preset widths: the preset width is... It can be calculated using the following formula. Scope (one); in, The width of the lane 3 along the goaf; The horizontal distance from the rotation base point of the main roof to the coal face; For the pressure of the top plate; The volume force is the direct impact force. Coal seam thickness; The final strength of filler 5; The initial strength of filler 5 is taken as 1 / 10. ; The elastic modulus of filler 5; The elastic modulus of the direct top of the filling zone 4; The elastic modulus of the direct bottom of the filling zone 4; The direct top thickness of filling zone 4; The direct bottom thickness of filling zone 4; This refers to the distance between the top and bottom of the ceiling. The length of the key block at the top; This is the rock fragmentation coefficient. Within the preset width determined by Formula 1 above... Within the specified range, the filling body 5 can provide stable support to the roof, preventing excessive stress from causing the filling body 5 to crush and fail. It can also reduce the amount of filling material used, thereby reducing the time required for filling material injection and the formation of the filling body 5, and improving the mining efficiency of the working face.

[0028] In some embodiments, the filling and retaining method includes determining a preset width within the range of a above. Multiple hydraulic supports 7 are installed at intervals along the width of the filling area 4 on the side of the goaf 2 closest to the working face 1 to support the roof of the goaf 2 on the side closest to the working face 1. The preset width of filling zone 4 is determined by the following formula 2. , (two); in, , The width of the hydraulic support 7; The number of hydraulic supports 7. This is the average width between two adjacent hydraulic supports 7. The preset width of the filling zone 4 is determined based on the hydraulic supports 7 and Formula 2 above. This allows for the precise determination of the preset width of the filling zone 4, ensuring effective support for the roof of the goaf 2 and guaranteeing the safety and integrity of the goaf-side roadway 3.

[0029] In some implementations, the filling and retaining method includes: verifying the preset width through numerical simulation experiments. The rationality of the preset width was further verified through numerical simulation experiments, thereby ensuring the support effect of the filling body 5. Compared with the actual field verification method, the cost is lower and the cycle is shorter.

[0030] In some implementations, the numerical simulation verification method includes: in a numerical simulation experiment, according to a preset width Determine the fracture status of the top plate of filling zone 4. If the top plate of filling zone 4 fractures, readjustment is required. To recalculate until the preset width. This ensures that the top plate of filling zone 4 does not fracture. The optimal preset width is determined iteratively using numerical simulation. This ensures that the roof of the filling area 4 is not fractured by the filling body 5, thus effectively supporting the roof of the filling area 4 and ensuring the integrity and safety of the goaf retainer 3.

[0031] In the above, the preset width of the filling zone 4 is determined by combining theoretical calculations and numerical simulations to ensure the accuracy of the preset width.

[0032] In some embodiments, the backfilling and retaining method includes: determining the strength of the backfill material 5. By determining the strength of the backfill material 5, damage such as crushing, shearing failure, or deformation of the backfill material 5 is avoided, thereby enabling the backfill material 5 to provide stable and effective support to the roof of the backfill area 4.

[0033] It should be noted that the type and proportion of filling material can be selected based on the strength of the filling body 5.

[0034] In some embodiments, the method for determining the strength of the backfill 5 is as follows: In the early stage of mining, the load on the roof of the gob-side retainer 3 is determined based on one cycle of pressure, and the one-day strength of the backfill 5 is greater than the load on the roof of the gob-side retainer 3; in the later stage of mining, the backfill 5 can support the roof of the gob-side retainer 3 without fracture. At different stages of mining, dynamic and differentiated requirements are placed on the strength of the backfill 5. When the working face 1 is subjected to the first cycle of pressure, the load acting on the backfill 5 and the gob-side retainer 3 is dynamic and increases rapidly. The one-day strength of the backfill 5 is greater than the load on the roof of the gob-side retainer 3, requiring the backfill material to have early strength and rapid hardening characteristics to ensure that the support structure can effectively support the roof of the support structure in the early stage of mining and prevent the backfill 5 from being damaged in the early stage of formation; the strength requirements for the backfill 5 in the later stage of mining ensure that the backfill 5 can support the roof without fracture or deformation during long-term support, so that the backfill material has an extremely high strength growth rate in the early stage and long-term strength in the later stage of mining. This allows the filling material 5 to effectively bear the load of the top plate and has a certain degree of deformation adaptability.

[0035] The first periodic pressure mentioned above refers to the situation after the initial roof collapse of working face 1. If the collapsed direct roof cannot fill the goaf 2, as working face 1 advances, the area of ​​the suspended old roof will continue to increase. When its own weight exceeds the strength limit of the old roof, the old roof will break and collapse for the first time, and working face 1 will experience pressure. This is the first periodic pressure of working face 1.

[0036] In some embodiments, the filling area 4 is enclosed by the roof of the goaf 2, the floor of the goaf 2, the rock strata behind the goaf 2, and two retaining rock supports 6 spaced apart on both sides of the filling area 4 along its width. The roof of the goaf 2 is managed by the caving method. The gangue falling from the roof of the goaf 2 accumulates in the filling area 4 and mixes with the filling material to form the filling body 5. The gangue falling from the roof can effectively bear the load of the roof. The setting of the retaining rock supports 6 can prevent the gangue from falling from the roof of the goaf 2 other than the filling area 4.

[0037] See Figure 1In another aspect, the present invention provides a backfilling and retaining device for implementing any of the above-mentioned backfilling and retaining methods. The backfilling and retaining device includes two rock-blocking supports 6, which are spaced apart on both sides of the backfilling area 4 along its width direction, and together with the roof of the goaf 2, the bottom of the goaf 2, and the rock strata behind the goaf 2, they form the backfilling area 4. The front end of the backfilling area 4 along the mining direction has an injection port for injecting backfilling material. The two rock-blocking supports 6 are spaced apart along the width of the filling area 4, which limits the width of the filling area 4 and ensures the spatial stability of the filling area 4. The rock-blocking supports 6, together with the top plate, bottom plate and the rock strata behind, form a cavity that is closed on five sides and open on one side, ensuring that the paste-like filling material fills the entire filling area 4 and forms a high-strength filling body 5. The rock-blocking supports 6 can prevent the rock from the goaf 2 outside the filling area 4 from falling into the filling area 4, ensuring the strength of the filling body 5. Moreover, the setting of the rock-blocking supports 6 is less expensive than the paste filling supports in the prior art.

[0038] In some embodiments, the backfilling and retaining device further includes a traction support 8, which is used to pull the rock-blocking support 6 to move along the mining direction. The traction support 8 enables the rock-blocking support 6 to move, forming a new backfilling zone 4 as the working face 1 is mined, so as to form a continuous backfill body 5.

[0039] After mining a certain length along the mining direction, the working face 1 stops mining and uses the traction support 8 to pull the rock-blocking support 6 forward to form a new filling area 4 with the roof of the goaf 2, the floor of the goaf 2 and the already formed filling body 5. Filling material is injected into this new filling area 4 to form a new filling body 5. After the filling body 5 solidifies, the working face 1 continues mining, thus forming a continuous filling body 5.

[0040] In some embodiments, the traction support 8 is a hydraulic support 7, used to support the roof of the goaf 2 on the side closest to the working face 1. The traction support 8 can not only pull the rock-blocking support 6 to move and continuously enclose a new filling area 4, but also serve as a hydraulic support 7 to support the roof of the goaf 2, thereby reducing the number of equipment required and lowering the cost of the filling and retaining method.

[0041] In some embodiments, the filling and retaining device includes a filling assembly for injecting filling material into the filling zone 4. The filling assembly injects the filling material into the filling zone 4 to form a filling body 5, ensuring the continuous and stable formation of the filling body 5.

[0042] See Figure 1The filling assembly includes a filling material storage tank 9 and a delivery pipeline 10. The filling material storage tank 9 is located on the ground and is used to store filling material. The delivery pipeline 10 connects the filling material storage tank 9 and the filling area 4. The filling material storage tank 9 located on the ground can store filling material, and the filling material is delivered to the filling area 4 through the delivery pipeline 10 to complete the injection of filling material into the filling area 4.

[0043] It should be noted that a filling channel connecting the ground and the goaf 3 is opened downwards along the ground, and the delivery pipeline 10 extends to the filling area 4 through the filling channel and the goaf 3 in sequence.

[0044] As described above, the conveying pipeline 10 includes a surface conveying pipeline installed on the ground and connected to the filling material storage device 9, an underground conveying pipeline installed in the filling channel, and an underground conveying pipeline installed in the goaf retention 3. The underground conveying pipeline connects the surface conveying pipeline and the underground conveying pipeline. The output end of the underground conveying pipeline is connected to the filling area 4. The surface conveying pipeline, the underground conveying pipeline, and the underground conveying pipeline are all kept straight, and the bends are connected by elbows with a bending radius of not less than 1.5m.

[0045] Among them, the surface conveying pipeline 10 uses Φ194×14mm seamless steel pipe, the underground conveying pipeline 10 uses Φ194×18mm seamless steel pipe, and the conveying pipeline 10 along the goaf 3 uses Φ159×12mm seamless steel pipe, so that the conveying pipeline 10 can withstand a large conveying pressure and ensure the safe and efficient conveying of filling materials.

[0046] In some embodiments, the filling and retaining device further includes a fixing member for securing the delivery pipeline 10 to the goaf retaining 3. The fixing member can secure the delivery pipeline 10 in the goaf retaining 3 to prevent displacement and damage to the delivery pipeline 10.

[0047] In the above, the fasteners include U-shaped pipe clamps and pipe supports. The pipe supports are fixedly installed at the bottom plate of the goaf 3, and the U-shaped pipe clamps are connected to the pipe supports and used to support the conveying pipeline 10.

[0048] The distance between adjacent fixing components is determined based on the geological conditions of the goaf 3 and the length of the conveying pipeline 10. Optionally, the distance between adjacent fixing components can be 6m.

[0049] In some embodiments, the filling and retaining device further includes a buffer element disposed at the bottom of the conveying pipeline 10. The buffer element disposed at the bottom of the conveying pipeline 10 can create a buffer between the conveying pipeline 10 and the goaf retaining 3 or the fixing element, thereby preventing damage to the conveying pipeline 10.

[0050] Optionally, the buffer can be a pad placed at the bottom of the delivery pipeline 10. The pad can be a wooden pad.

[0051] Alternatively, the buffer can also be a rubber pad placed between the U-shaped pipe clamp and the delivery pipe 10.

[0052] In some embodiments, the strength of the filling material forming the filling body 5 is less than the strength of the rock strata of the roof and floor of the goaf-side retaining 3. If the strength of the filling body 5 is greater than the strength of the rock strata of the roof and floor of the goaf-side retaining 3, the hard filling body 5 will hardly deform during the process of roof sinking and floor bulging, while the relatively soft rock strata of the roof and floor of the goaf-side retaining 3 will deform and be damaged. Therefore, setting the strength of the filling body 5 to be less than the strength of the rock strata of the roof and floor of the goaf-side retaining 3 allows the filling body 5 to deform, thus avoiding the transfer of excessive concentrated stress to the roof and floor of the goaf-side retaining 3, preventing the roof and floor of the goaf-side retaining 3 from being cut off, and protecting the integrity and safety of the goaf-side retaining 3.

[0053] The preset width of the filling zone 4 is determined based on theoretical calculations and numerical simulations. In the initial stage of mining of working face 1, mining is stopped after a certain length of mining. The filling zone 4 is planned according to the preset width. The filling zone 4 is formed by two rock-blocking supports 6, the roof, the floor, and the rock strata behind the goaf 2. The paste filling material is injected into the filling zone 4 through the filling component. The filling material forms the filling body 5 that supports the roof. As working face 1 continues to advance, two traction supports 8 pull two rock-blocking supports 6 to move forward synchronously with the hydraulic supports 7. After mining continues for a certain length of mining, mining is stopped. The two rock-blocking supports 6, the roof, the floor, and the filling body 5 behind the filling zone 4 form a new filling zone 4. As working face 1 is mined, the above operation is repeated multiple times to form a continuous filling body 5.

[0054] The preferred embodiments of the present invention have been described in detail above with reference to the accompanying drawings; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention. This includes combining various specific technical features in any suitable manner. To avoid unnecessary repetition, the present invention will not further describe the various possible combinations. However, these simple modifications and combinations should also be considered as part of the content disclosed in this invention and are all within the protection scope of this invention.

Claims

1. A method for filling and retaining tunnels, characterized in that, The filling and retaining method includes: A filling area (4) is enclosed on the side of the goaf (2) near the goaf roadway (3) with a predetermined width; and Filling material is injected into the filling area (4) to form a filling body (5) that supports the top plate of the goaf (2).

2. The filling and retaining method according to claim 1, characterized in that, The filling and retaining method includes determining the range of the preset width: The preset width is It can be calculated using the following formula. Scope (one); in, The width of the passageway (3) along the passageway; The horizontal distance from the rotation base point of the main roof to the coal face; For the pressure of the top plate; The volume force is the direct impact force. Coal seam thickness; The final strength of the filling material (5); The initial strength of the filling material (5) is taken as 1 / 10. ; The elastic modulus of the filling material (5); The elastic modulus of the direct top of the filling region (4); The elastic modulus of the direct bottom of the filling region (4); The direct top thickness of the filling area (4); The direct bottom thickness of the filling area (4); This refers to the distance between the top and bottom of the ceiling. The length of the key block at the top; is the rock fragmentation coefficient.

3. The filling and retaining method according to claim 2, characterized in that, The filling and retaining method includes the above-mentioned Determine the preset width within the range : Multiple hydraulic supports (7) are spaced apart along the width direction of the filling area (4) on the side of the goaf (2) near the working face (1) to support the roof of the goaf (2) near the working face (1). The preset width of the filling area (4) is determined by the following formula 2. , (two); in, , The width of the hydraulic support (7); The number of the hydraulic supports (7) The average width between two adjacent hydraulic supports (7) is given.

4. The filling and retaining method according to claim 3, characterized in that, The filling and retaining method includes: verifying the preset width through numerical simulation experiments. The rationality of it.

5. The filling and retaining method according to claim 4, characterized in that, The numerical simulation verification method includes: in the numerical simulation experiment, according to a preset width Determine the fracture status of the top plate of the filling area (4). When the top plate of the filling area (4) fractures, readjust... To recalculate until the preset width This prevents the top plate of the filling area (4) from cracking.

6. The filling and retaining method according to claim 1, characterized in that, The filling and retaining method includes: determining the strength of the filling body (5).

7. The filling and retaining method according to claim 6, characterized in that, The method for determining the strength of the filling material (5) is as follows: In the early stage of mining, the load on the roof of the goaf retainer (3) is determined based on one cycle of pressure. The one-day strength of the filling body (5) is greater than the load on the roof of the goaf retainer (3). In the later stage of mining, the filling body (5) can support the roof of the goaf retainer (3) without causing it to break.

8. A filling and retaining device, characterized in that, For implementing the backfilling and retaining method according to any one of claims 1-7, the backfilling and retaining device includes two rock-blocking supports (6), the two rock-blocking supports (6) are spaced apart on both sides of the backfilling area (4) along its width direction, and together with the top plate of the goaf (2), the bottom plate of the goaf (2) and the rock strata behind the goaf (2) to form the backfilling area (4), the backfilling area (4) has an injection port for injecting the backfilling material at the front end along the mining direction.

9. The filling and retaining device according to claim 8, characterized in that, The backfilling and retaining device further includes a traction support (8), which is used to pull the rock-blocking support (6) to move along the mining direction; and / or The filling and retaining device includes a filling component for injecting the filling material into the filling zone (4).

10. The filling and retaining device according to claim 9, characterized in that, The traction support (8) is a hydraulic support and is used to support the top plate of the goaf (2) on the side close to the working face (1); and / or The filling assembly includes: A filling material storage container (9) is disposed on the ground and is used to store the filling material; as well as Delivery pipeline (10) connects the filling material storage container (9) and the filling area (4).

11. The filling and retaining device according to claim 10, characterized in that, The filling and retaining device further includes a fixing member for fixing the delivery pipeline (10) to the goaf retaining device (3); and / or The filling and retaining device also includes a buffer element, which is disposed at the bottom of the conveying pipeline (10).

12. The filling and retaining device according to claim 8, characterized in that, The strength of the filling material forming the filling body (5) is less than the strength of the rock strata of the top and bottom plates of the goaf-retention tunnel (3).

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