Supporting sliding template for gob-side entry retaining and gob-side entry retaining mining method

Abstract

The application discloses a gob-side entry retaining supporting sliding template and a gob-side entry retaining mining method, and belongs to the technical field of coal mining. The gob-side entry retaining supporting sliding template comprises two symmetrical template units, a baffle assembly and a roof-contacting flexible mold bag. The baffle assembly is used for connecting the two template units and forming a closed space together. The two roof-contacting lifting oil cylinders are used for pressing the corresponding skirt belts and steel bars on the roof of the roadway, and the closed space is poured with concrete through a concrete feeding port. The gob-side entry retaining mining method adopts the gob-side entry retaining supporting sliding template. The gob-side entry retaining supporting sliding template is used in the gob-side entry retaining mining process, the time for supporting the template is shortened, the overall construction efficiency is improved, and the safety risk in the mining process is reduced.

Description

Technical Field

[0001] This invention belongs to the field of coal mining technology, specifically a sliding template for gob-side roadway support and a gob-side roadway mining method. Background Technology

[0002] Coal mining is a high-risk and complex engineering activity. Traditional coal mining methods typically leave numerous coal pillars in the mine to support the roof, leading to resource waste. To improve coal resource recovery, the goaf-supported pillarless mining technology has gradually gained attention. This method was developed to address the problems of high roadway support costs, significant coal pillar losses, and low coal resource utilization rates associated with traditional mining methods. Pillarless mining technology primarily uses cast-in-place concrete walls to replace coal pillars for roof control, achieving zoned unloading of the overlying strata and managing the roof through natural caving in the goaf. This method eliminates the need for protective coal pillars, allowing for direct coal resource recovery after the entire working face is mined, significantly improving economic efficiency.

[0003] The existing technologies for pillarless roadway retention along the goaf mainly include the following four types:

[0004] (1) Reinforced concrete block method: This method uses precast reinforced concrete blocks to build supports to maintain the roadway; wooden pads or mortar are installed between each concrete block and between the support and the roof to level it, but manual stone masonry is labor-intensive, has a very low safety factor and high cost.

[0005] (2) Gangue backfilling belt method: Gangue backfilling belt uses gangue from the goaf or gangue from the top of the roadway to form a strip to maintain the roadway; it is economical and practical, but the manual stone masonry work is large, the safety factor is extremely low, and the compression is also large, so it is mostly used in thinner coal seams.

[0006] (3) Flexible formwork support technology: developed by Professor Wang Xiaoli of Xi'an University of Science and Technology; the flexible formwork support technology can adapt to roof subsidence and improve the stability of the roadway. However, this technology increases the cost of flexible formwork and cannot be implemented in roadways with a mining height of more than 4 meters.

[0007] (4) High water content material roadway side filling and roadway retention: High water content material can meet the engineering needs of various strength requirements by adjusting the water-cement ratio to change the compressive strength of the filling body, but the cost is high.

[0008] In summary, current gob-side roadway retention methods primarily employ concrete and high-water-content materials for roadway backfilling. Existing gob-side roadway retention technologies require substantial material and labor costs for support, formwork, and other components, resulting in excessively high material and labor costs. Furthermore, the equipment used in these existing construction processes is insufficient in terms of reliability and automation, impacting construction costs, efficiency, and safety. Summary of the Invention

[0009] This invention overcomes the shortcomings of the prior art and proposes a sliding template for gob-side roadway support and a gob-side roadway mining method;

[0010] To achieve the above objectives, the present invention is implemented through the following technical solution:

[0011] A sliding formwork for goaf retention includes two symmetrically arranged formwork units, a baffle assembly, and a roof-connecting flexible formwork bag;

[0012] The template unit includes a height-adjustable outer template, and a top-lifting hydraulic cylinder is connected to the top of the outer template; the baffle assembly is used to connect the left and right template units and together with the two template units, it forms a closed space.

[0013] The flexible formwork bag is a bag-shaped structure with open top and bottom. Skirts are provided on both sides of the top of the flexible formwork bag, and steel bars are threaded inside the skirts. A concrete inlet is provided on one side of the flexible formwork bag. The corresponding skirts and steel bars are pressed onto the roadway roof by the telescopic ends of two lifting cylinders. Concrete is poured into the enclosed space through the concrete inlet.

[0014] Furthermore, the template unit also includes a lower support for the lifting cylinder, an inner template, and lifting cylinders for both inner and outer templates; the lower support for the lifting cylinder is located inside the inner template, the outer template is sleeved on the outside of the inner template, and the outer template and the inner template are slidably connected; the bottom of the lifting cylinders for both inner and outer templates is fixedly installed on the lower support for the lifting cylinder, and the telescopic ends of the lifting cylinders for both inner and outer templates are connected to the top lifting cylinder.

[0015] Furthermore, a lifting cylinder upper support is fixedly installed on the inner side of the outer template near the top, and the bottom of the top lifting cylinder is fixedly installed on the lifting cylinder upper support; the telescopic ends of the inner and outer template lifting cylinders are connected to the bottom of the lifting cylinder upper support.

[0016] Furthermore, the template unit also includes a balancing cylinder and a base; the center of the base is fixedly connected to the lower support of the lifting cylinder, and the bottom of the inner template is fixedly connected to the base; the balancing cylinder is located on one side of the base and connected to the base.

[0017] Furthermore, the baffle assembly includes a tie rod sleeve, a tie rod, and a baffle; a row of mounting holes is provided at both ends of the left and right side walls of the outer and inner templates; the mounting holes on the outer template and the mounting holes on the inner template are correspondingly positioned; when the outer template rises relative to the inner template to a set height, the tie rod sleeve passes through the corresponding mounting holes of the left and right template units, and the tie rod passes through the tie rod sleeve and is fixed to the left and right template units by bolts, etc.; baffles are vertically installed between the front and rear faces of the left and right template units respectively, and the baffles are fixed to the tie rod sleeve, forming a closed space through the front and rear baffles and the left and right template units.

[0018] Furthermore, based on the length of the poured concrete wall, the lengths of the left and right template units are extended to form two sets of template units. Each set of template units includes 3-4 spaced-apart outer templates. A flexible formwork bag with a matching length is lifted by the two sets of template units together, and the flexible formwork bag is equipped with a skirt that matches the number of lifting cylinders.

[0019] Furthermore, self-locking rollers are installed at the bottom of the base, and tracks are installed on the tunnel floor, with the rollers and tracks slidingly connected and engaged.

[0020] A method for mining along the goaf, employing the aforementioned sliding formwork for goaf retention support, includes the following steps:

[0021] Step 1: Arrange multiple longwall faces in sequence. Cut the roof of the coal seam at the longwall cut of the first longwall face to relieve pressure. Then, arrange the support and mining facilities of the first longwall face at the location of the longwall cut. Arrange the sliding formwork for the gob-side retaining roadway on the side of the support near the longwall cut of the first longwall face in the auxiliary transport roadway. The length of the sliding formwork for the gob-side retaining roadway support is adapted to the length of the support.

[0022] Step 2: Mining the first longwall face. At the same time, concrete is poured into the closed space enclosed by the sliding formwork of the goaf retainer through the concrete feed inlet. The longwall face advances one cycle. After the longwall face stops mining, the baffle assembly is removed and the sliding formwork of the goaf retainer is moved forward according to the longwall advance length.

[0023] Step 3: Complete the mining of the entire first longwall face in sequence according to Step 2 until the stop line is reached; after reaching the stop line, remove the supports and mining facilities, and close the roadway of the first longwall face.

[0024] Step 4: Complete the mining and support of the entire working face according to Steps 1 to 3.

[0025] Furthermore, in step one, the first and second longwall faces are first arranged. The two roadways of the first longwall face are used as intake airways, and the one roadway of the second longwall face is used as the return airway of the first longwall face. The intake airway on the side of the first longwall face away from the second longwall face is used as the transport airway of the first longwall face, and the intake airway on the side of the first longwall face closer to the second longwall face is used as the auxiliary transport airway of the first longwall face. The innermost side of the first longwall face is the longwall cut-out. Roofing pressure relief holes are drilled in the transport airway, auxiliary transport airway, and longwall cut-out of the first longwall face.

[0026] When mining the second longwall face, the auxiliary haulage roadway of the first longwall face is used as the haulage roadway of the second longwall face, and the return airway of the first longwall face is used as the auxiliary haulage roadway of the second longwall face. The return airway of the second longwall face is arranged in the third longwall face.

[0027] Furthermore, the blasting time of the roof-cutting and pressure-relief holes in the transport roadway and auxiliary transport roadway is synchronized with the advance time of the longwall face.

[0028] The beneficial effects of this invention compared to the prior art are as follows:

[0029] 1. Improved construction efficiency: The use of sliding formwork for gob-side roadway support significantly shortens the formwork erection time and improves overall construction efficiency during gob-side roadway mining. No additional roadway excavation is required, greatly increasing coal mining efficiency.

[0030] 2. Environmental Protection and Energy Saving: Compared with traditional methods, the sliding formwork for gob-side roadway support is a one-time investment that can be reused, reducing material consumption and labor costs during gob-side roadway mining. It avoids the need for coal pillars, improving coal resource recovery; it also reduces roadway excavation, lowering energy consumption and environmental pollution during the mining process.

[0031] 3. Enhanced safety: The use of sliding formwork for gob-side entry and exit roadway support during the mining process effectively reduces safety hazards during construction. The sliding formwork for gob-side entry and exit roadway support has good compressive and tensile strength, which can effectively support the roadway, reduce the occurrence of safety accidents such as roadway collapse, and improve the safety of the operation.

[0032] 4. Fewer limitations: Flexible formwork bags cannot exceed 4 meters in height for mines with complex geological conditions and for roadway retention along the goaf, while U-shaped sliding formwork is not limited by geological conditions and roadway height.

[0033] This invention enables the direct recovery of coal resources after the entire longwall face is mined, improving economic efficiency, protecting the environment and saving energy, and reducing safety risks during the mining process. It can bring more beneficial effects to the safe production and resource protection of mines. Attached Figure Description

[0034] Figure 1 This is a front view of the sliding formwork for the goaf support in the retracted state.

[0035] Figure 2 Side views of two template units in the retracted state;

[0036] Figure 3 This is a front view of the sliding formwork for the goaf support in the raised state.

[0037] Figure 4The images show the side views of two template units in the raised state.

[0038] Figure 5 Schematic diagram of the structure of the top flexible mold bag Figure 1 ;

[0039] Figure 6 Schematic diagram of the structure of the top flexible mold bag Figure 2 ;

[0040] Figure 7 This is a front view of concrete pouring using a sliding formwork supported by a goaf-side retaining structure.

[0041] Figure 8 This is a schematic diagram showing the retraction state of the hydraulic cylinder of the sliding formwork supporting the goaf after concrete pouring.

[0042] Figure 9 The front view of the poured concrete wall formed by removing the sliding formwork of the goaf retainer after pouring concrete;

[0043] Figure 10 A schematic diagram of the working face layout in step one of the goaf retention mining method;

[0044] Figure 11 This is a schematic diagram showing the arrangement of the sliding formwork for the gob-side retaining support in step two of the gob-side retaining mining method.

[0045] Figure 12 This is a schematic diagram showing the movement of the sliding template for the gob-side support after one cycle of the longwall face advance in step three.

[0046] Figure 13 This is a schematic diagram showing the mining process after the completion of the entire first longwall face in step four.

[0047] Figure 14 This is a schematic diagram showing the movement of the sliding formwork and support frame along the goaf to the second longwall face.

[0048] In the diagram: 1. Top-mounted lifting cylinder; 2. Upper support of the lifting cylinder; 3. Outer formwork; 4. Lifting cylinders for both inner and outer formwork; 5. Inner formwork; 6. Lower support of the lifting cylinder; 7. Base; 8. Balance cylinder; 9. Concrete wall; 12. Connecting plate; 13. Mounting hole; 14. Base plate; 15. Tunnel roof; 16. Flexible formwork bag for top-mounted installation; 17. Tie rod sleeve; 18. Tie rod; 20. Concrete inlet; 21. Skirt; 22. Reinforcing steel; 23. Baffle; 24. Support. Detailed Implementation

[0049] To make the technical problems to be solved, the technical solutions, and the beneficial effects of this invention clearer, the invention will be further described in detail with reference to the embodiments and accompanying drawings. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention. The technical solutions of this invention are described in detail below with reference to the embodiments and accompanying drawings, but the scope of protection is not limited thereto. Example 1

[0050] See Figures 1 to 9 This embodiment proposes a sliding formwork for roadway support along the goaf; it includes two symmetrically arranged formwork units on the left and right, a baffle assembly for connecting the two formwork units on the left and right, and a flexible formwork bag 16 for roof support;

[0051] The template unit includes a balance cylinder 8, a base 7, a lower support for a lifting cylinder 6, an inner template 5, inner and outer template lifting cylinders 4, an outer template 3, an upper support for a lifting cylinder 2, and a top-mounted lifting cylinder 1.

[0052] The balancing cylinder 8 and the base 7 are both installed on the bottom plate 14 of the tunnel. The balancing cylinder 8 is located on one side of the base 7 and connected to the base 7. The balancing cylinder 8 is used to adjust the verticality of the base 7. When the base 7 tilts, the extension length of the balancing cylinder 8 is adjusted to adjust the base 7 to a state perpendicular to the bottom plate 14. The balancing cylinder 8 is an existing structure.

[0053] The center of the base 7 is fixedly connected to the lower support 6 of the lifting cylinder, and the bottom of the inner template 5 is fixedly connected to the base 7; and the lower support 6 of the lifting cylinder is located inside the inner template 5; it should be noted that the inner template 5 and the outer template 3 have similar structures, both being rectangular box-shaped structures. The width between the outer walls of the inner template 5 is adapted to the width between the inner walls of the outer template 3, so that the outer template 3 is fitted outside the inner template 5, and the outer template 3 and the inner template 5 are slidably connected.

[0054] The bottom of the inner and outer template lifting cylinder 4 is fixedly installed on the lower support 6 of the lifting cylinder. The upper support 2 of the lifting cylinder is fixedly installed on the inner side of the outer template 3 near the top. The telescopic end of the inner and outer template lifting cylinder 4 is connected to the bottom of the upper support 2 of the lifting cylinder. After the inner and outer template lifting cylinder 4 is opened, the upper support 2 of the lifting cylinder can be pushed up and down, thereby driving the outer template 3 to move up and down relative to the inner template 5 through the upper support 2 of the lifting cylinder. The bottom of the top-connecting lifting cylinder 1 is fixedly installed on the upper support 2 of the lifting cylinder. The telescopic end of the top-connecting lifting cylinder 1 extends to the outer side of the top of the outer template 3 and is used to connect the top-connecting flexible mold bag 16.

[0055] The baffle assembly includes a pull rod sleeve 17, a pull rod 18, and a baffle 23; a row of mounting holes 13 is provided at both the front and rear ends of the left and right side walls of the outer template 3 and the inner template 5; the mounting holes 13 on the outer template 3 and the mounting holes 13 on the inner template 5 are in corresponding positions. When the telescopic ends of the inner and outer template lifting cylinders 4 of the left and right template units move upward simultaneously, the outer template 3 rises relative to the inner template 5. When the set height is reached, the top lifting cylinders 1 of the left and right template units are opened. A top-mounting flexible formwork bag 16 is connected between the two top-mounting lifting cylinders 1. By raising the telescopic ends of the top-mounting lifting cylinders 1, the top of the top-mounting flexible formwork bag 16 is brought into contact with the tunnel roof 15. At this time, the tie rod sleeve 17 is passed through the corresponding mounting holes 13 of the left and right template units, and the tie rod 18 is passed through the tie rod sleeve 17 and the left and right template units are fixed by bolts, etc. Baffles 23 are vertically set between the front and rear faces of the left and right template units respectively, and the baffles 23 are fixed to the tie rod sleeve 17. The front and rear baffles 23 and the left and right template units form a closed space, and concrete is poured into the closed space from the top-mounting flexible formwork bag 16.

[0056] The flexible formwork bag 16 is a square bag-shaped structure with open top and bottom. Skirts 21 are connected to the top two sides of the flexible formwork bag 16, and steel bars 22 are threaded inside the skirts 21. A concrete inlet 20 is provided on one side of the flexible formwork bag 16. The two skirts 21 and steel bars 22 are pressed down by the telescopic ends of the two lifting cylinders 1; then, concrete pumps, pipelines and other equipment are connected through the concrete inlet 20 to pour concrete into the enclosed space.

[0057] It should be noted that the outer sides of the left and right template units are open, which facilitates the installation of the tie rod sleeve 17, the tie rod 18, and the inspection and observation of the raising and lowering of the outer template 3. The top flexible formwork bag 16 should be inserted into the outer template 3 to a certain depth to avoid gaps between the top flexible formwork bag 16 and the outer template 3 during concrete pouring. The tie rod sleeve 17, tie rod 18, and top flexible formwork bag 16 can be installed between the left and right template units.

[0058] It should be noted that, based on the length of the poured concrete wall 9, the lengths of the left and right template units can be increased to form two sets of template units. Each set of template units includes 3-4 spaced outer templates 3. A flexible formwork bag 16 with a corresponding length is lifted by the two sets of template units, and the flexible formwork bag 16 is equipped with skirts 21 that match the number of lifting cylinders 1. In this case, only baffles 23 need to be installed at the front and back of each set of template units.

[0059] It should be noted that if the existing two sets of template units need to be lengthened, four sets of template units can be used, which can be connected and fixed at the front and rear by connecting plates 12. This allows multiple sliding templates for goaf support to be spliced ​​together for use.

[0060] To facilitate movement, self-locking rollers are installed at the bottom of the base 7, and a track is installed on the bottom plate 14 of the tunnel. The rollers and the track are connected and slidably cooperate to facilitate the movement of the entire template. Example 2

[0061] This embodiment proposes a method for mining with a gob-side retaining tunnel, which is implemented using a gob-side retaining tunnel support sliding template as described in Embodiment 1. The specific steps are as follows:

[0062] Step 1, see Figure 10 First, the first and second longwall faces are arranged. The two roadways of the first longwall face are used as intake airways, and the one roadway of the second longwall face is used as return airway of the first longwall face. This two-intake-one-return arrangement method can solve the problem of excessive gas in the upper angle in high-gas mines.

[0063] The intake airway on the side of the first longwall face furthest from the second longwall face is designated as the transport airway for the first longwall face, and the intake airway on the side closer to the second longwall face is designated as the auxiliary transport airway for the first longwall face; the innermost side of the first longwall face is the longwall cut-out.

[0064] In the first longwall mining face, roof pressure relief holes are drilled in the transport roadway, auxiliary transport roadway, and longwall cutting face. The spacing, depth, and angle of the roof pressure relief holes are determined based on the lithology and burial depth. The depth of the roof pressure relief holes is generally more than twice the width of the mining area roadway.

[0065] Step 2, see Figure 11 First, the roof pressure relief holes of the longwall face are blasted or other methods are used to relieve pressure on the coal seam roof. The amount of explosives used in each roof pressure relief hole is determined based on the lithology of the coal seam roof. Then, the support 24, coal mining machine, and other coal mining facilities for the first longwall face are arranged at the location of the longwall face. The aforementioned gob-side retaining sliding template is installed on one side of the support 24 near the longwall face in the auxiliary transport roadway of the first longwall face. The length of the gob-side retaining sliding template is adapted to the length of the support 24.

[0066] The specific installation process of the sliding formwork for roadway support along the goaf is as follows:

[0067] Before mining, first raise the outer formwork 3. If the formwork is not vertical after raising, use the balancing cylinder 8 to adjust its verticality. Then install the tie rod sleeve 17 and tie rod 18. Next, fix the skirt 21 of the flexible formwork bag 16 to the top lifting cylinder 1. Then raise the top lifting cylinder 1 to press the skirt 21 of the flexible formwork bag 16 onto the roadway roof 15. To ensure better top connection and prevent the flexible formwork bag 16 from sagging, a steel bar 22 should be threaded through the skirt 21 of the flexible formwork bag 16, and the top lifting cylinder 1 should be pressed together with the skirt 21 and the steel bar 22 when it is raised. Then, fix the baffle 23 on the outside.

[0068] Step 3, see Figure 12 During mining, concrete is poured into the enclosed space formed by the sliding formwork of the goaf retaining roadway through the concrete feed inlet 20. The poured concrete solidifies simultaneously with mining. After the mining face advances for one cycle, the tie rod sleeve 17, tie rod 18, and baffle 23 of the sliding formwork of the goaf retaining roadway are removed. Then, the height of the sliding formwork of the goaf retaining roadway is lowered to separate it from the poured concrete wall 9. The sliding formwork of the goaf retaining roadway is moved forward with the help of external force according to the mining advance length. Before moving the sliding formwork of the goaf retaining roadway, the concrete wall 9 must reach a certain strength before the formwork can be removed.

[0069] During the mining process, the blasting time of the roof-cutting and pressure-relief holes in the haulage roadway and auxiliary haulage roadway must be synchronized with the advance time of the longwall face. In this method, each advance cycle of the longwall face should not exceed 6 meters. If each advance cycle exceeds 6 meters, ventilation fans must be installed on the outside of the sliding formwork supporting the goaf.

[0070] Step 4, see Figure 13 and Figure 14 Following step three, the entire first longwall face is mined sequentially until it reaches the stop line. After reaching the stop line, the support 24 and coal mining facilities are withdrawn, and the roadway of the first longwall face is sealed off. The auxiliary haulage roadway of the first longwall face is used as the haulage roadway of the second longwall face, and the return airway of the first longwall face is used as the auxiliary haulage roadway of the second longwall face. The return airway of the second longwall face is arranged in the third longwall face, and then the second longwall face is mined and supported according to the methods of steps one to three.

[0071] Step 5: Complete the mining and support of the entire working face by following the steps above.

[0072] The above description is a further detailed explanation of the present invention in conjunction with specific preferred embodiments. It should not be considered that the specific embodiments of the present invention are limited to this. For those skilled in the art, several simple deductions or substitutions can be made without departing from the present invention, and all of these should be considered to fall within the scope of patent protection determined by the submitted claims.

Claims

1. A sliding formwork for roadway support along the goaf, characterized in that, It includes two symmetrically arranged template units on the left and right, a baffle assembly, and a top-mounted flexible formwork bag (16); The template unit includes a height-adjustable outer template (3), and a top-mounted lifting cylinder (1) is connected to the top of the outer template (3); the baffle assembly is used to connect the left and right template units and together with the two template units form a closed space; The top-mounted flexible formwork bag (16) is a bag-shaped structure with open top and bottom. Skirts (21) are provided on both sides of the top of the top flexible formwork bag (16). Steel bars (22) are inserted inside the skirts (21). A concrete inlet (20) is provided on one side of the top-mounted flexible formwork bag (16). The corresponding skirts (21) and steel bars (22) are pressed onto the roadway roof (15) by the telescopic ends of the two top-mounted lifting cylinders (1). Concrete is poured into the enclosed space through the concrete inlet (20). The template unit also includes a lower support (6) for the lifting cylinder, an inner template (5), and inner and outer template lifting cylinders (4); the lower support (6) for the lifting cylinder is located inside the inner template (5), the outer template (3) is sleeved on the outside of the inner template (5), and the outer template (3) is slidably connected to the inner template (5); the bottom of the inner and outer template lifting cylinders (4) is fixedly installed on the lower support (6), and the telescopic end of the inner and outer template lifting cylinders (4) is connected to the top lifting cylinder (1); The baffle assembly includes a tie rod sleeve (17), a tie rod (18), and a baffle (23). A row of mounting holes (13) is provided at both the front and rear ends of the left and right side walls of the outer template (3) and the inner template (5). The mounting holes (13) on the outer template (3) and the mounting holes (13) on the inner template (5) are in corresponding positions. When the outer template (3) rises relative to the inner template (5) and reaches the set height, the tie rod sleeve (17) passes through the corresponding mounting holes (13) of the left and right template units, and the tie rod (18) passes through the tie rod sleeve (17) and the left and right template units are fixed by bolts. Baffles (23) are vertically set between the front and rear faces of the left and right template units respectively, and the baffles (23) are fixed to the tie rod sleeve (17). The front and rear baffles (23) and the left and right template units form a closed space.

2. The sliding formwork for gob-side roadway support according to claim 1, characterized in that, The upper support (2) of the lifting cylinder is fixedly installed on the inner side of the outer template (3) near the top, and the bottom of the top lifting cylinder (1) is fixedly installed on the upper support (2); the telescopic end of the inner and outer template lifting cylinder (4) is connected to the bottom of the upper support (2).

3. The sliding formwork for gob-side roadway support according to claim 1, characterized in that, The template unit also includes a balance cylinder (8) and a base (7); the center of the base (7) is fixedly connected to the lower support (6) of the lifting cylinder, and the bottom of the inner template (5) is fixedly connected to the base (7); the balance cylinder (8) is located on one side of the base (7) and connected to the base (7).

4. The sliding formwork for gob-side roadway support according to claim 1, characterized in that, According to the length of the poured concrete wall, the length of the two left and right template units is increased to form two sets of template units. Each set of template units includes 3-4 spaced outer templates (3). A flexible top-mounted formwork bag (16) with a length adapted by the two sets of template units is lifted together. The flexible top-mounted formwork bag (16) is equipped with a skirt (21) that matches the number of top-mounted lifting cylinders (1).

5. A sliding formwork for goaf retention support according to claim 3, characterized in that, A self-locking roller is installed at the bottom of the base (7), and a track is installed on the tunnel floor plate (14). The roller and the track are slidably connected and cooperate.

6. A method for mining along the goaf with a roadway retention system, characterized in that, The method employs a sliding formwork for roadway support as described in any one of claims 1-5, and includes the following steps: Step 1: Arrange multiple longwall faces in sequence, cut the roof of the coal seam at the longwall cut of the first longwall face to relieve pressure, and then arrange the support (24) and mining facilities of the first longwall face at the location of the longwall cut; arrange the sliding template for the goaf retention support on the side of the support (24) near the longwall cut of the auxiliary transport roadway of the first longwall face; the length of the sliding template for the goaf retention support is adapted to the length of the support (24); Step 2: Mining the first mining face. At the same time, concrete is poured into the closed space enclosed by the sliding template of the goaf retaining roadway through the concrete feed port (20). The mining face advances one cycle. After the mining face stops mining, the baffle assembly is removed and the sliding template of the goaf retaining roadway is moved forward according to the mining advance length. Step 3: Complete the mining of the entire first longwall face in accordance with Step 2 until it reaches the stop line; after reaching the stop line, remove the support (24) and mining facilities, and close the roadway of the first longwall face; Step 4: Complete the mining and support of the entire working face according to Steps 1 to 3; In step one, the first and second longwall faces are arranged. The two roadways of the first longwall face are used as intake airways, and the one roadway of the second longwall face is used as the return airway of the first longwall face. The intake airway on the side of the first longwall face away from the second longwall face is used as the transport airway of the first longwall face, and the intake airway on the side of the first longwall face closer to the second longwall face is used as the auxiliary transport airway of the first longwall face. The innermost part of the first longwall face is the longwall cut-out. Roof relief holes are drilled in the transport airway, auxiliary transport airway, and longwall cut-out of the first longwall face. When mining the second longwall face, the auxiliary haulage roadway of the first longwall face is used as the haulage roadway of the second longwall face, and the return airway of the first longwall face is used as the auxiliary haulage roadway of the second longwall face. The return airway of the second longwall face is arranged in the third longwall face.

7. The method for mining along the goaf with roadway retention according to claim 6, characterized in that, The blasting time of the roof-cutting and pressure-relief holes in the transport roadway and auxiliary transport roadway is synchronized with the advance time of the longwall face.

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