Folding long-distance telescopic targeted filling hydraulic support and end filling mining method

Abstract

The present invention relates to a foldable, long-distance, telescopic, targeted filling hydraulic support, comprising a base, a hydraulic column, a top beam, a filling support plate, and a boom. The rear end of the top beam is hinged with a filling support plate, and the boom is fixed to the lower part of the filling support plate. The boom comprises a slewing mechanism, a lifting mechanism, a folding mechanism, and a filling mechanism connected in sequence. The boom is used to achieve multi-directional, long-distance filling work, and when in use, it is arranged with conventional hydraulic intervals to solve the high cost disadvantage of using filling supports for all traditional filling working faces. Based on the targeted filling hydraulic support, the present invention also proposes an end-filling mining method, which only fills at the end of the goaf and forms a basin-bottom goaf, solving the problems of large opening of longitudinal cracks in the overburden at the mining boundary and large penetration of longitudinal cracks between adjacent rock layers. At the same time, the middle of the working face rationally utilizes the evolution law of the crack field to allow it to close by itself, thereby controlling ecological restoration from the source and reducing damage to the overburden by coal mining activities.

Description

Technical Field

[0001] The present invention relates to the technical field of mine filling and mining, and in particular to a foldable long-distance telescopic targeted filling hydraulic support and an end filling and mining method. Background Art

[0002] Coal is the main energy source in my country, and the high-intensity mining areas in the west provide an important guarantee for my country's energy security. The Shendong mining area is a typical high-intensity mining area for shallow coal seams. High-intensity mining produces a large number of overburden cracks and surface cracks. A large number of experimental studies have found that such overburden cracks are divided into temporary cracks and permanent cracks. As the working face advances along the inclination, temporary cracks will go through three stages: closing-cracking-closing. This area is generally located in the fully mined area, corresponding to the flat, non-deformed area in the center of the surface subsidence basin. Figure 4 (a). After the rock layers in this area are broken, the longitudinal cracks between the rock blocks are perpendicular to the rock layers and the cracks are closed. Permanent cracks appear at the mining boundary. This area is generally located on both sides of the fully mined area, corresponding to the inclined part of the surface subsidence basin directly above the working face. Figure 4 (a) After mining is completed at the working face, the rock strata near the mining boundary form a masonry beam interlocking structure. Rock blocks within the same stratum rotate at different angles, causing them to open at large angles at adjacent longitudinal fracture surfaces. The longitudinal fractures between adjacent strata are highly interconnected, and due to the influence of the coal pillars mined at the end, the longitudinal fractures in this area remain difficult to close until mining is complete, causing damage to numerous ecological elements.

[0003] In response to the stratum and surface damage caused by coal mining, underground filling mining technology is an important method to solve this problem. However, the existing underground filling mining technologies have not reasonably utilized the evolution and distribution laws of the fracture field mentioned above. The more widely used underground solid material filling and paste filling technologies often fill the entire goaf, requiring the opening of a dedicated working space on the working face, the deployment of dedicated single pillars, unit supports and special filling equipment, and a large number of workers to carry out filling and material transportation operations, affecting the safe and efficient production of the working face.

[0004] To address the stratum and surface damage caused by coal mining, the Shenhua Mining District has adopted a wide range of post-mining reclamation technologies. However, this primarily focuses on repairing the surface environment, and cannot restore the damage to aquifers and water loss caused by mining. Furthermore, because post-mining reclamation technologies overlook the mechanisms by which mining-induced rock movement affects rock and soil structural damage and underground water loss, as well as the environmental effects of rock movement, maintaining their effectiveness often requires significant costs. Clearly, it is crucial to develop more targeted key technologies for stratum damage reduction, fracture repair, and groundwater ecological restoration, addressing the source of mining-induced rock movement. Summary of the Invention

[0005] In response to the problems existing in the existing technology, the present invention proposes to partially fill the goaf only at the end of the working face to solve the problems of large opening of longitudinal cracks in the overburden at the mining boundary and large penetration of longitudinal cracks between adjacent rock layers. At the same time, the middle part of the working face rationally utilizes the evolution law of the crack field to allow it to close by itself. This can greatly improve production efficiency and reduce filling costs. At the same time, it can also effectively solve the problem of initiation of overburden cracks and surface cracks at the mining boundary, control ecological restoration from the source, and reduce the damage to the overburden strata caused by coal mining activities.

[0006] Specifically, the present invention proposes a foldable long-distance telescopic targeted filling hydraulic support, comprising a base, a hydraulic column, a top beam, a filling support plate and a boom; the base and the top beam are respectively connected to the bottom and top ends of the hydraulic column, the rear end of the top beam is hinged with a filling support plate and is supported by a third hydraulic cylinder, the boom is fixed to the lower part of the filling support plate, and the boom comprises a slewing mechanism, a lifting mechanism, a folding mechanism and a filling mechanism connected in sequence; the slewing mechanism is fixed to the lower part of the filling support plate for realizing the rotation of the boom in the horizontal direction; the two ends of the lifting mechanism are respectively connected to the lower part of the slewing mechanism and the front end of the folding mechanism for realizing the movement of the boom in the vertical direction; the rear end of the folding mechanism is connected to the filling mechanism for controlling the filling mechanism to approach or move away from the targeted filling hydraulic support; the filling mechanism is located at the end of the entire boom.

[0007] As a preferred solution, there are four hydraulic columns, which are arranged vertically on the base and the top beam in two rows and two columns.

[0008] As a preferred solution, a first support plate and a second support plate are arranged between the top beam and the base, the upper end of the first support plate is hinged to the top beam near the front hydraulic column, the lower end is hinged to the upper end of the second support plate, the lower end of the second support plate is hinged to the base near the rear hydraulic column, and the hinge point between the first support plate and the second support plate protrudes backward.

[0009] As a preferred solution, a top beam extension is provided at the front end of the top beam, the top beam extension is hinged to the top beam, and a guard plate is hinged to the front end of the top beam extension and is controlled by a first hydraulic cylinder.

[0010] As a preferred embodiment, the filling support plate is formed by multiple sections of rectangular plates or inverted U-shaped plates that are sequentially connected, wherein the rectangular plate / inverted U-shaped plate close to the rear end of the top beam is the outermost section, and the multiple sections of rectangular plates / inverted U-shaped plates are controlled to extend and retract by a second hydraulic cylinder.

[0011] As a preferred embodiment, the cylinder end of the third hydraulic cylinder is connected to the rear end of the top beam, or the rear end of the base, and the telescopic rod end is connected to the filling support plate.

[0012] As a preferred embodiment, the rotating mechanism includes a rotating base, a rotating shell and a driving motor. The upper end of the rotating base is fixed on the filling support plate. The rotating shell is rotatably connected to the rotating base and rotates under the drive of the driving motor. The rotating shell is semicircular as a whole and the semicircular outer circumference faces downward.

[0013] As a preferred embodiment, the lifting mechanism is Z-shaped as a whole, including a first support arm, a second support arm and a crossbeam which are hinged in sequence, wherein the upper end of the first support arm is hinged to the lower part of the rotating shell of the rotating mechanism, and the fourth hydraulic cylinder is used to connect the lower part of the rotating shell of the rotating mechanism and the upper end face of the first support arm, the fifth hydraulic cylinder is used to connect the lower end face of the first support arm and the upper end face of the second support arm, and the sixth hydraulic cylinder is used to connect the lower end face of the second support arm and the upper end face of the crossbeam; the interior of the crossbeam is a hollow structure for transporting filling materials.

[0014] As a preferred embodiment, the folding mechanism includes a folding rod group, a folding pumping hose, a double-acting hydraulic cylinder and two flanges; the front and rear ends of the folding rod group are respectively fixed on the flanges and can be extended and retracted, the front end flange is fixed to the rear end of the beam, and the rear end flange is fixedly connected to the filling mechanism; a folding pumping hose is arranged inside the folding rod group, the front end of the folding pumping hose is connected to the rear end outlet of the hollow structure of the beam through the flange, and the rear end is connected to the filling mechanism through the flange.

[0015] As a preferred embodiment, the filling mechanism includes a rotating part, a rotating shaft and a filling gun. The rotating part includes an external rotating seat and a hollow rotating shaft located inside the rotating seat and sealed and rotatably connected to the rotating seat. The rear end of the hollow rotating shaft is provided with a rotating shaft that rotates radially along the hollow rotating shaft. The filling gun is fixed on the rotating shaft, and the filling gun is also connected to the rear end of the hollow rotating shaft.

[0016] Specifically, the present invention also proposes a method for filling the end of a goaf, using the above-mentioned targeted filling hydraulic support, comprising the following steps:

[0017] Step 1: Determine the end filling width

[0018] A 3DEC numerical model was established based on the mining parameters and geological parameters of the working face. The appropriate filling width at the end of the goaf was determined through numerical simulation, ensuring that the longitudinal fracture apertures between rock blocks in the rock layers at both ends of the working face and the surface deformation parameters met the requirements for aquifer protection and surface deformation control.

[0019] Step 2: Arrange the hydraulic support

[0020] Based on the mining parameters of the working face, targeted filling hydraulic supports and conventional hydraulic supports are selected, and the hydraulic supports are arranged from one end of the working face to the other. The position of the targeted filling hydraulic support is determined according to the filling coverage of the targeted filling hydraulic support; the slurry outlet of the filling pipeline is connected to the front end of the crossbeam of the targeted filling hydraulic support;

[0021] Step 3: Mining the working face

[0022] Carry out mining on the working face and keep the roof directly above the goaf stable;

[0023] Step 4: Fill the end of the working surface

[0024] A targeted filling hydraulic support is used to fill the paste at the end of the goaf, and the next coal cutting is performed before the filling solidifies, so that the roof collapses and presses on the filling, compressing and deforming the filling at the end of the working face to form a basin-type goaf;

[0025] Step 5: Repeat steps 3 and 4 until the entire working surface is mined.

[0026] Beneficial effects: 1. The targeted filling hydraulic support of the present invention is provided with a filling support plate at the rear end of the support, and a boom is provided on the filling support plate, so that multi-directional and long-distance filling work can be realized through the boom. When in use, it can be arranged with conventional hydraulic intervals to solve the disadvantage of high filling cost of using filling supports for all traditional filling working surfaces.

[0027] 2. For shallow buried high-intensity mining conditions, the present invention proposes to only partially fill the goaf at the end of the working face, and creatively proposes to carry out subsequent coal cutting work before the filling body solidifies, so that the roof collapses and deforms the filling body in the goaf at the end of the working face, thereby forming a basin-type goaf. This can solve the problems of large opening of longitudinal cracks in the overburden at the mining boundary and large penetration of longitudinal cracks between adjacent rock layers. At the same time, the middle part of the working face rationally utilizes the evolution law of the crack field and allows it to close by itself. This can greatly improve production efficiency, reduce filling costs, control ecological restoration from the source, and reduce the damage to the overburden by coal mining activities. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 This is a schematic diagram of the structure of the foldable long-distance telescopic targeted filling hydraulic support of the present invention;

[0029] Figure 2 This is a schematic diagram of the boom structure of the targeted filling hydraulic support of the present invention;

[0030] Figure 3 This is a schematic diagram of the layout of the end-fill mining working face of the present invention (only part of the hydraulic support is shown);

[0031] Figure 4This is a schematic diagram of surface subsidence after mining at the working face;

[0032] In the figure: base 1, hydraulic column 2, first support plate 201, second support plate 202, top beam 3, top beam extension 301, first hydraulic cylinder 302, third hydraulic cylinder 303, guard plate 304, filling support plate 4, boom 5, slewing base 601, slewing shell 602, fourth hydraulic cylinder 701, first support arm 702, fifth hydraulic cylinder 703, second support arm 704, sixth hydraulic cylinder Cylinder-705, crossbeam-706, folding rod assembly-801, folding pumping hose-802, double-acting hydraulic cylinder-803, flange-804, rotating part-901, rotating shaft-902, filling gun-903, control system-10; filling body-11, goaf-12, targeted filling hydraulic support-13, conventional hydraulic support-14, coal seam-15, unfilled surface subsidence curve-16, filled surface subsidence curve-17. DETAILED DESCRIPTION

[0033] In order to better understand the technical content of the present invention, specific embodiments are given and described as follows in conjunction with the accompanying drawings. In the present invention, various aspects of the present invention are described with reference to the accompanying drawings, in which many illustrative embodiments are shown. The embodiments of the present invention are not limited to those described in the accompanying drawings. It should be understood that the present invention is implemented by any of the various concepts and embodiments introduced above, as well as the concepts and implementation methods described in detail below, because the concepts and embodiments disclosed in the present invention are not limited to any implementation method. In addition, some aspects disclosed in the present invention can be used alone or in any appropriate combination with other aspects disclosed in the present invention.

[0034] like Figure 1 、 Figure 2As shown, the present invention proposes a foldable long-distance telescopic targeted filling hydraulic support, including a base 1, a hydraulic column 2, a top beam 3, a filling support plate 4, a boom 5 and a control system 10. The base 1, the hydraulic column 2 and the top beam 3 are the core bearing components of the targeted filling hydraulic support. The base 1 and the top beam 3 are arranged in a rectangular style as a whole and are respectively connected to the bottom and top ends of the hydraulic column 2. The hydraulic column 2 is a four-column type, that is, there are 4 of them, which are arranged vertically in two rows and two columns on the base 1 and the top beam 3. The top beam 3 is used to bear the load from the top plate of the working surface and transmit it to the base 1 through the hydraulic column 2 to play a top protection role. The base 1 is placed on the bottom plate of the working surface during testing. The hydraulic column 2 has a telescopic function, which is controlled by the control system 10 to adjust the support height of the targeted filling hydraulic support. In order to improve the stability and load-bearing capacity of the targeted filling hydraulic support, a first support plate 201 and a second support plate 202 are provided between the top beam 3 and the base 1. The upper end of the first support plate 201 is hinged to the top beam 3 near the front hydraulic column, and the lower end is hinged to the upper end of the second support plate 202. The lower end of the second support plate 202 is hinged to the base 1 near the rear hydraulic column. The hinge between the first support plate 201 and the second support plate 202 protrudes backward. In order to improve the support range of the top beam 3, a top beam extension 301 is provided at the front end of the top beam 3. The top beam extension 301 is hinged to the top beam 3. The front end of the top beam extension 301 is hinged to a guard plate 304. The cylinder end of the first hydraulic cylinder 302 is connected to the front end of the top beam 3, and the telescopic rod end is connected to the guard plate 304. The guard plate 301 plays a role in preventing the coal wall from flaking. The first hydraulic cylinder 302 is controlled to extend and retract by the control system 10.

[0035] The rear end of the top beam 3 is hinged with a filling support plate 4 for maintaining the filling operation space and protecting the targeted filling hydraulic support; the filling support plate 4 is formed by multiple sections of rectangular plates or inverted U-shaped plates connected in sequence, which can realize the extension and contraction of the filling support plate 4 to control the top control range of the filling support plate 4, wherein the section of rectangular plate / inverted U-shaped plate close to the rear end of the top beam 3 is the outermost section, and the rear sections of rectangular plates / inverted U-shaped plates are sequentially connected in the previous section, and the multiple sections of rectangular plates / inverted U-shaped plates are controlled to extend and retract by a second hydraulic cylinder (not shown in the figure); Figure 1 The illustrated embodiment is provided with two rectangular plates / inverted U-shaped plates, and the second hydraulic cylinder is controlled to extend and retract via the control system 10. The filling support plate 4 is supported by a third hydraulic cylinder 303, the cylinder end of which is connected to the rear end of the top beam 3 or the rear end of the base 1, and the telescopic rod end is connected to the filling support plate 4. The third hydraulic cylinder 303 has a telescopic function and is controlled by the control system 10.

[0036] A boom 5 is provided at the lower portion of one end of the filling support plate 4 close to the top beam 3. Figure 1An embodiment of the invention is specifically arranged at the lower part of the outermost rectangular plate / inverted U-shaped plate), and the boom 5 includes a slewing mechanism, a lifting mechanism, a folding mechanism and a filling mechanism connected in sequence. The slewing mechanism is fixed to the lower part of one end of the filling support plate 4 close to the top beam 3 ( Figure 1 One embodiment is specifically arranged at the lower part of the outermost rectangular plate / inverted U-shaped plate), which is used to realize the rotation of the boom 5 in the horizontal direction; the two ends of the lifting mechanism are respectively connected to the lower part of the slewing mechanism and the front end of the folding mechanism, which are used to realize the movement of the boom 5 in the vertical direction; the rear end of the folding mechanism is connected to the filling mechanism, which is used to control the filling mechanism to approach or move away from the targeted filling hydraulic support (or away from or close to the goaf); the filling mechanism is located at the end of the entire boom 5, and plays a role in controlling the injection speed of the filling material.

[0037] The slewing mechanism includes a slewing base 601, a slewing shell 602, and a drive motor. The upper end of the slewing base 601 is fixed to the filling support plate 4. The slewing shell 602 is rotatably connected to the slewing base 601 and rotates under the drive of the drive motor. The slewing shell is semicircular in shape, with the outer periphery of the semicircle facing downward. The drive motor is connected to the control system 10, and the drive speed and direction are controlled by the drive system 10. The drive motor can be a hydraulic motor. The control system 10 controls the emulsion to flow into the hydraulic motor. The rotation of the hydraulic motor drives the movement of the slewing shell. When a hydraulic motor is used, the rotation angle of the slewing mechanism is controlled by controlling the emulsion flow rate. The drive motor can be an electric motor. The control system 10 controls the power supply to the electric motor. When the power is on, the slewing shell is driven to rotate.

[0038] The lifting mechanism is in a Z-shape as a whole, including a first support arm 702, a second support arm 704 and a crossbeam 706 which are hinged in sequence, wherein the upper end of the first support arm 702 is hinged to the lower part of the rotating shell of the rotating mechanism, and the lower end is hinged to the upper end of the second support arm 704, and the lower end of the second support arm is hinged to the upper front end of the crossbeam 706; it also includes a fourth hydraulic cylinder 701, a fifth hydraulic cylinder 703 and a sixth hydraulic cylinder 705, the cylinder end of the fourth hydraulic cylinder 701 is connected to the lower part of the rotating shell of the rotating mechanism, and the telescopic rod end is connected to the first support arm 702. The upper end surface, the cylinder end of the fifth hydraulic cylinder 703 is connected to the lower end surface of the first support arm 702, and the telescopic rod end is connected to the upper end surface of the second support arm 704. The cylinder end of the sixth hydraulic cylinder 705 is connected to the lower end surface of the second support arm 704, and the telescopic rod end is connected to the upper end surface of the crossbeam 706. The fourth hydraulic cylinder 701, the fifth hydraulic cylinder 703 and the sixth hydraulic cylinder 705 are controlled to be telescopic by the control system 10; the interior of the crossbeam 706 is a hollow structure, and its front end is connected to the slurry outlet of the filling pipeline to serve the purpose of transporting filling materials.

[0039] The folding mechanism includes a folding rod group 801, a folding pumping hose 802, a double-acting hydraulic cylinder 803 and two flanges 804; the front and rear ends of the folding rod group 801 are respectively fixed on the flanges 804, the front end flange 804 is fixed to the rear end of the beam 706, and the rear end flange 804 is fixedly connected to the filling mechanism; a plurality of double-acting hydraulic cylinders 803 connected to the control system 10 are arranged on the folding rod group 801, and the extension and shortening of the double-acting hydraulic cylinders 803 are controlled by the control system 10 to realize the telescopic movement of the folding mechanism; a folding pumping hose 802 is arranged inside the folding rod group 801, which is made of high-pressure-bearing rubber material, and the front end of the folding pumping hose 802 is connected to the rear end outlet of the hollow structure of the beam 706 through a flange, and the rear end is connected to the filling mechanism through a flange.

[0040] The filling mechanism is located at the tail end of the boom 5 and includes a rotating portion 901, a rotating shaft 902 and a filling gun 903. The rotating portion 901 includes an external rotating seat and a hollow rotating shaft located inside the rotating portion and sealed and rotatably connected thereto. The hollow rotating shaft can rotate 360° around the rotating seat. A rotating shaft 902 that rotates radially along the hollow rotating shaft is provided at the rear end of the hollow rotating shaft. A filling gun 903 is fixed on the rotating shaft 902, and the filling gun is also connected to the hollow rotating shaft. At the rear end, the rotating shaft 902 can drive the filling gun 903 to rotate (swing) ±90° around the rotating shaft 902; a valve is provided on the filling gun 903, and the start or stop of the filling operation can be controlled by the valve, and the filling speed can be controlled by the size of the valve opening; the filling mechanism is connected to the control system 10 to realize automatic control of the rotation of the rotating part 901, automatic control of the rotating shaft 902 to drive the filling gun 903 to swing, and automatic control of the opening and closing and filling speed of the filling gun 903.

[0041] The solution further includes a monitoring system, which includes but is not limited to a video monitoring probe, a laser scanning probe, an ultrasonic positioning probe, a gas monitoring probe and a temperature sensor, wherein the video monitoring probe is used to observe the condition of the goaf and the operation condition of the equipment, the laser scanning probe is used to monitor the shape of the filling body and the size of the filling space, the ultrasonic positioning probe is used to detect the position of the filling mechanism, and the gas monitoring probe and the temperature sensor are used to detect the gas and fire conditions in the goaf; the probes or sensors included in the above-mentioned monitoring system are only some of the probes or sensors listed in the present invention, and other monitoring probes or sensors can be added to achieve more detection functions.

[0042] like Figure 3-4 As shown, the present invention also proposes a method for filling the end of a goaf, which uses the above-mentioned targeted filling hydraulic support 13, wherein the working face parameters for filling mining are: mining height 3.2m, burial depth 160m, and mining width 313m; and includes the following steps:

[0043] Step 1: Determine the end filling width

[0044] A 3DEC numerical model is established based on the mining parameters and geological parameters of the working face. Numerical simulation is used to determine the longitudinal fissure apertures between rock blocks in the various rock strata at both ends of the working face after mining, as well as the surface deformation parameters. Filling bodies 11 of various widths are placed at both ends of the working face, set to 10m, 15m, 20m, 25m, 30m, and 35m (the widths at both ends can also be set to different widths depending on the inclination of the coal seam). Numerical simulation is used to determine the longitudinal fissure apertures between rock blocks in the various rock strata at both ends of the working face, as well as the surface deformation parameters, at each end filling width. A critical filling body width is determined based on the requirements for aquifer protection and surface deformation control, which in this embodiment is 25m.

[0045] Step 2: Arrange the hydraulic support

[0046] A targeted filling hydraulic support 13 was selected. The targeted filling hydraulic support was 1.5m wide, the hydraulic column 2 had a telescopic range of 2.8-3.5m, and the maximum extension length of the folding mechanism was 8m. Based on the direct top collapse step distance of 4.5m, the maximum extension length of the filling support plate 4 was selected to be 6.0m. A conventional hydraulic support 14 was selected. The conventional hydraulic support was 1.5m wide, the hydraulic column 2 had a telescopic range of 2.8-3.5m, and the end hydraulic support also adopted the same frame width as the conventional hydraulic support.

[0047] Hydraulic supports are arranged from one end of the working face to the other, with a spacing of 0.2m between adjacent hydraulic supports. Including the end hydraulic supports of the two lanes of the working face, a total of 184 hydraulic supports are arranged, numbered 1#-184#; among them, 5#, 14#, 171#, and 180# hydraulic supports adopt targeted filling hydraulic supports;

[0048] Connect the slurry outlet of the filling pipeline to the front end of the beam 706 of the targeted filling hydraulic support;

[0049] Step 3: Mining the working face

[0050] The working face is mined, and the mining step distance, i.e., the footage of each cut, is 0.8m. Based on the breaking step distance of the immediate roof of 4.5m, the filling spacing is determined to be 4.0m, i.e., the end of the working face is filled every 5 cuts, so that the immediate roof above the goaf 12 still maintains a certain stability;

[0051] Step 4: Fill the end of the working surface

[0052] Extend the filling support plate 4 to a length of not less than 4.0m, and perform filling operations in sequence from the end of the working face to the middle, i.e., first use the 5# and 180# targeted filling hydraulic supports for filling, and then use the 14# and 171# targeted filling hydraulic supports for filling; during filling, the left and right and up and down positions of the filling gun are controlled by the boom 5; for each targeted filling hydraulic support 13, first fill the area to be filled on both sides thereof, and then perform the filling operation at the position directly behind it, and fill from back to front upward;

[0053] The filling material is a paste filling material, and the filling height is slightly less than the mining height, about 3.0m; before the filling body 11 solidifies, specifically after the initial setting, the next coal cutting can be carried out to cause the roof to collapse and cover the filling body. Figure 4 (b)- Figure 4 As shown in (c), as the working face continues to advance (the coal seam 15 is continuously mined), the overlying rock strata that have lost the support of the hydraulic support break and sink under the action of gravity, and compress and deform the filling body of the goaf at the end of the working face. The cross-sectional shape of the filling body along the inclination of the working face changes from a nearly rectangular shape at the beginning to a nearly triangular shape after being squeezed. The entire goaf changes from a cliff-like goaf when not filled to a basin-like goaf after filling; that is, the equivalent mining inclination profile of the working face changes from a rectangle to a basin-like shape. The change in the equivalent mining space at the end of the working face directly affects the evolution of the mining fracture field of the overlying rock strata, reduces the opening and penetration of the longitudinal fractures of the roof rock layer above the end of the working face, closes the fractures in the conductive aquifer, and the water in the aquifer no longer flows away. At the same time, the surface sinking basin becomes gentle at the two ends of the working face, with small deformation. That is, the goaf end filling method of the present invention can slow down the development of overlying rock fractures and surface fractures at the mining boundary, and realizes source-controlled ecological restoration.

[0054] It should be emphasized here that the existing paste filling method uses full-goaf filling, and the next cycle of coal cutting is carried out only after the filling body solidifies. The purpose is to improve the supporting capacity of the filling body to prevent roof subsidence and damage, and to fill as close to the top as possible. This is achieved by preventing the formation of mining cracks in the working face to achieve water-preserving mining and surface deformation control. The end-filling mining method of the present invention, on the other hand, requires the next cycle of coal cutting to be carried out before the filling body solidifies. This requires the normal collapse of the roof to cover the deformation of the filling body to form a basin-shaped goaf. This is achieved by reducing the opening and penetration of the mining cracks at the end of the working face to achieve water-preserving mining and surface deformation control.

[0055] Step 5: Repeat steps 3 and 4 until the entire working surface is mined.

[0056] While the present invention has been described above with reference to preferred embodiments, this is not intended to limit the present invention. Persons skilled in the art will readily appreciate that various modifications and variations can be made without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention shall be determined by the appended claims.

Claims

1. A method for filling the end of a goaf, adopting a foldable long-distance telescopic targeted filling hydraulic support, the targeted filling hydraulic support includes a base, a hydraulic column, a top beam, a filling support plate and a boom; the base and the top beam are respectively connected to the bottom and top ends of the hydraulic column, the rear end of the top beam is hinged with a filling support plate and supported by a third hydraulic cylinder, the boom is fixed to the lower part of the filling support plate, and the boom includes a slewing mechanism, a lifting mechanism, a folding mechanism and a filling mechanism connected in sequence; the slewing mechanism is fixed to the lower part of the filling support plate to realize the rotation of the boom in the horizontal direction; the two ends of the lifting mechanism are respectively connected to the lower part of the slewing mechanism and the front end of the folding mechanism to realize the movement of the boom in the vertical direction; the rear end of the folding mechanism is connected to the filling mechanism to control the filling mechanism to approach or move away from the targeted filling hydraulic support; the filling mechanism is located at the end of the entire boom; It is characterized in that The following steps are involved: Step 1: Determine the end filling width A 3DEC numerical model was established based on the mining parameters and geological parameters of the working face. The appropriate filling width at the end of the goaf was determined through numerical simulation, ensuring that the longitudinal fracture apertures between rock blocks in the rock layers at both ends of the working face and the surface deformation parameters met the requirements for aquifer protection and surface deformation control. Step 2: Arrange the hydraulic support Based on the mining parameters of the working face, targeted filling hydraulic supports and conventional hydraulic supports are selected, and the hydraulic supports are arranged from one end of the working face to the other. The position of the targeted filling hydraulic support is determined according to the filling coverage of the targeted filling hydraulic support; the slurry outlet of the filling pipeline is connected to the front end of the crossbeam of the targeted filling hydraulic support; Step 3: Mining the working face Carry out mining on the working face and keep the roof directly above the goaf stable; Step 4: Fill the end of the working surface A targeted filling hydraulic support is used to fill the paste at the end of the goaf, and the next coal cutting is performed before the filling solidifies, so that the roof collapses and presses on the filling, compressing and deforming the filling at the end of the working face to form a basin-type goaf; Step 5: Repeat steps 3 and 4 until the entire working surface is mined.

2. The method for filling the end of a goaf according to claim 1, characterized in that: There are four hydraulic columns, which are arranged vertically on the base and the top beam in two rows and two columns.

3. The method for filling the end of a goaf according to claim 2, characterized in that: A first support plate and a second support plate are arranged between the top beam and the base. The upper end of the first support plate is hinged to the top beam near the front hydraulic column, and the lower end is hinged to the upper end of the second support plate. The lower end of the second support plate is hinged to the base near the rear hydraulic column. The hinge point of the first support plate and the second support plate protrudes backward.

4. The method for filling the end of a goaf according to claim 1, characterized in that: The filling support plate is formed by multiple sections of rectangular plates or inverted U-shaped plates that are connected in sequence, among which the rectangular plate / inverted U-shaped plate near the rear end of the top beam is the outermost section, and the multiple sections of rectangular plates / inverted U-shaped plates are controlled to extend and retract by a second hydraulic cylinder.

5. The method for filling the end of a goaf according to claim 1 or 4, characterized in that: The cylinder body end of the third hydraulic cylinder is connected to the rear end of the top beam or the rear end of the base, and the telescopic rod end is connected to the filling support plate.

6. The method for filling the end of a goaf according to claim 1, characterized in that: The rotating mechanism includes a rotating base, a rotating shell and a driving motor. The upper end of the rotating base is fixed on the filling support plate. The rotating shell is rotatably connected to the rotating base and rotates under the drive of the driving motor. The rotating shell is semicircular as a whole and the semicircular outer circumference faces downward.

7. The method for filling the end of a goaf according to claim 6, characterized in that: The lifting mechanism is Z-shaped as a whole, and includes a first support arm, a second support arm and a crossbeam which are hinged in sequence, wherein the upper end of the first support arm is hinged to the lower part of the rotating shell of the rotating mechanism, and the fourth hydraulic cylinder is used to connect the lower part of the rotating shell of the rotating mechanism and the upper end face of the first support arm, the fifth hydraulic cylinder is used to connect the lower end face of the first support arm and the upper end face of the second support arm, and the sixth hydraulic cylinder is used to connect the lower end face of the second support arm and the upper end face of the crossbeam; the interior of the crossbeam is a hollow structure for transporting filling materials.

8. The method for filling the end of a goaf according to claim 7, characterized in that: The folding mechanism includes a folding rod group, a folding pumping hose, a double-acting hydraulic cylinder and two flanges; the front and rear ends of the folding rod group are respectively fixed on the flanges and can be extended and retracted, the front end flange is fixed to the rear end of the beam, and the rear end flange is fixedly connected to the filling mechanism; a folding pumping hose is arranged inside the folding rod group, the front end of the folding pumping hose is connected to the rear end outlet of the hollow structure of the beam through the flange, and the rear end is connected to the filling mechanism through the flange.

9. The method for filling the end of a goaf according to claim 8, characterized in that: The filling mechanism includes a rotating part, a rotating shaft and a filling gun. The rotating part includes an external rotating seat and a hollow rotating shaft located inside the rotating part and sealed and rotatably connected to the rotating seat. A rotating shaft that rotates radially along the hollow rotating shaft is provided at the rear end of the hollow rotating shaft. The filling gun is fixed on the rotating shaft, and the filling gun is also connected to the rear end of the hollow rotating shaft.

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