Non-pillar sublevel caving safety construction equipment and construction method thereof

Abstract

The invention relates to the technical field of underground mining, in particular to sill-pillar-free sublevel caving safety construction equipment and a construction method thereof. According to the technical scheme, the back-up chamber is arranged on one side of a previous horizontal draw shaft connection lane, the through distance from a blind roadway tunneled from a new horizontal slope ramp connection lane to a draw shaft is shortened to 35-30 m, and the effective operation distance of 22 m is reserved at the position of a through opening of the back-up chamber and the draw shaft. The equipment further comprises tunneling equipment arranged on a working face, a guide rail laid on the top of a roadway, a telescopic air pipe in sliding connection with the guide rail, a fixing frame, a filtering mechanism and a rotational flow mechanism, wherein the filtering mechanism and the rotational flow mechanism are arranged in the fixing frame. The rotational flow mechanism comprises a rotational flow cylinder, a guide cylinder, an air supply cylinder and a rotational flow plate. According to the method, the problems of poor ventilation, low slag discharging efficiency and the like in long-distance single-end roadway construction are effectively solved by optimizing roadway layout, synchronously propelling a ventilation system, performing multi-stage dust removal and dynamically adjusting the air flow direction, and safe and efficient construction is achieved.

Description

Technical Field

[0001] This invention relates to the field of underground mining technology, and in particular to a safety construction device and construction method for bottomless segmented caving. Background Technology

[0002] Sublevel caving, a highly efficient underground mining method, typically employs a top-down, segmented mining sequence. Before commencing mining at each new level, the development of the preparatory roadways for that level must be completed. The most crucial aspect is the excavation of connecting roadways from the upper level to the new level, forming a complete ore extraction and ventilation system. The efficiency and safety of this development process directly impact the production continuity and economic benefits of the entire mining system.

[0003] In traditional construction techniques, new-level development typically employs a long-distance, single-heading-way excavation method, starting with a connecting roadway on an inclined ramp. During construction, forced ventilation relies primarily on localized ventilation fans installed within the roadway, combined with rigid ventilation ducts, to dilute and remove fumes and dust generated at the working face. Simultaneously, since a complete ore extraction system has not yet been established at the new level, the excavated rock must be transported long distances by mining trucks to the upper level's pass for disposal. This operational method depends on standard mining tunneling equipment and transport vehicles, completing roadway excavation and support work through a phased, sequential approach.

[0004] However, traditional caving cut-out methods without bottom columns require vertically upward construction through blind wells or vertical trenches, resulting in harsh working environments and safety hazards such as blasting fume poisoning, rockfall, and falls from heights, especially under fractured and soft rock conditions. Existing well-cutting methods, such as conventional well sinking and riser drilling, while technically mature, suffer from high construction costs, poor safety, and strong dependence on geological conditions. Furthermore, with traditional methods, the long excavation distance of single-ended roadways significantly increases ventilation resistance, and the effective ventilation volume decreases sharply with distance. This leads to a large accumulation of blasting fumes within the roadway, which are difficult to dissipate. Even with continuous ventilation equipment operation, it still takes a considerable amount of time to reduce the concentration of harmful gases below safe levels. The persistent blasting fume pollution within the roadway not only threatens the health and safety of workers but also results in a significant waste of non-productive time while waiting for ventilation to reach safe levels, becoming a major technical bottleneck restricting the improvement of new-level development efficiency. Summary of the Invention

[0005] The purpose of this invention is to address the problems existing in the background technology by proposing a safe construction device and construction method for segmented collapse without a bottom column.

[0006] Firstly, this application provides a pillarless segmented caving safety construction device, based on the existing mining structure, forming a ramp connecting roadway at a new level, a chute located at the previous level, and a reversing chamber located at the new level. The existing mining structure includes a stage transport roadway, a chute connecting roadway, an intake air shaft, and a return air shaft. The chute is connected to a stage transport roadway via a chute connecting roadway. The intake air shaft is connected to a segmented access roadway via an intake air shaft connecting roadway. The return air shaft is also connected to the segmented access roadway via a return air shaft connecting roadway. The mining access roadway is connected to the cutting shaft via the segmented access roadway. The reversing chamber is located on the side of the connecting roadway adjacent to the chute. The connection distance from the single-ended roadway at the start of the inclined ramp connecting roadway to the chute is significantly shortened to within the range of 30-35 meters. At the connection point between the reversing chamber and the chute, an effective working distance of approximately 22 meters is reserved for vehicle turning around and unloading operations after the connection is completed. The single-ended roadway formed by the end excavation of the inclined ramp connecting roadway connects to the reversing chamber at its excavation end point, and is connected to the chute through the reversing chamber.

[0007] Optionally, the shortened penetration distance enables the single-ended roadway to quickly form a circulating ventilation loop with the chute after tunneling and blasting. The single-ended roadway is connected to a vertically installed ventilation shaft, and the ventilation shaft further connects the intake shaft to the mining route.

[0008] Optionally, after the single-ended roadway is connected to the chute, the reversing chamber is configured to connect to and serve the transport vehicles, so that the slag can be directly unloaded into the chute through the reversing chamber, thereby forming an independent slag discharge channel at this level.

[0009] Optionally, the construction equipment also includes a tunneling device installed at the working face of the single-ended roadway and a retractable ventilation duct installed in the middle of the single-ended roadway.

[0010] Optionally, the construction equipment also includes a guide rail laid on the top of the tunnel, wherein a telescopic tube is fixed inside the guide rail with a slider, one end of the telescopic tube is installed on the top of the tunneling equipment, and the other end is connected to a fixed frame set on the top of the ventilation shaft, wherein a filter mechanism and a vortex mechanism are installed inside the fixed frame.

[0011] Optionally, the filter assembly includes an air duct for supplying air and a filter assembly for filtering air. The filter assembly is installed at the bottom of the air duct, and a fan is installed on the inner wall of the air duct away from the filter assembly.

[0012] Optionally, the swirl assembly includes a swirl cylinder fixed to the middle of the inner wall of the duct. The inner wall of the swirl cylinder is sequentially equipped with an air outlet, a second guide cylinder, and a first guide cylinder from bottom to top. An air supply duct is fixed to the inner wall of the first and second guide cylinders. A swirl plate is installed on the inner wall of the air supply duct. Both the first and second guide cylinders are provided with multiple through holes with inclined angles.

[0013] Optionally, the swirl assembly further includes an exhaust hood for discharging internal air. The inner wall of the exhaust hood has multiple guide plates arranged in a linear array. A rotating shaft and a push rod are fixed at both ends of each guide plate. The rotating shaft is located at the middle of both ends of the guide plate, and the push rod is located at the upper end of both ends of the rotating shaft. A push plate slides on the outer wall of the push rod, and the outer walls of the push plate are connected by a longitudinal connecting rod. A transverse connecting rod is fixed at one end of the longitudinal connecting rod, and a double-sided rack is fixed in the middle of the transverse connecting rod. A motor is fixed inside the exhaust hood, and a transmission belt is provided at the output end of the motor. The transmission belt consists of two concave pulleys and a mating belt. An arc-shaped toothed ring is fixed to the top of each of the two concave pulleys, and the two arc-shaped toothed rings respectively mesh with the outer walls of the double-sided rack.

[0014] Optionally, the ventilation shaft extends through the interior of the mine to provide circulating air.

[0015] Secondly, the present invention provides a safe construction method for segmented collapse without a base column, applied to the safe construction equipment for segmented collapse without a base column described in the first aspect. The method includes the following steps: S1. Optimize the tunnel design and position the reversing chamber of the new level on the side of the connecting tunnel adjacent to the chute of the previous level; S2. Starting from the new horizontal inclined roadway connecting roadway, excavate a single-ended roadway towards the reversing chamber, controlling its excavation distance within the range of 35-30 meters, until it is connected to the chute; S3. During the tunneling process, the ventilation and dust removal system is activated to supply fresh air to the working face through the ventilation shaft and telescopic pipe, and the dust on the working face is treated by the filtration and cyclone mechanism. S4. After the single-ended roadway and the chute are connected, the reverse chamber is used as a passage to directly unload the slag into the horizontal chute for slag removal. S5. Adjust the position of the telescopic pipe and the angle of the guide plate according to the progress of the working face to control the air supply direction.

[0016] In summary, this application includes at least one of the following beneficial technical effects: This invention optimizes the tunnel layout, significantly shortens the length of single-ended tunnels, enables the rapid formation of a circulating ventilation loop after blasting, effectively solves the problem of blasting smoke accumulation, and greatly improves construction safety performance.

[0017] By further utilizing the shortened roadway distance and optimized slag removal channels, slag removal efficiency can be significantly improved, transportation costs reduced, and interference with production at the next level avoided.

[0018] Finally, through a mobile ventilation and dust removal system and a precise airflow control device, the working environment is continuously improved, ensuring the health and safety of construction workers and improving work efficiency. Attached Figure Description

[0019] Figure 1 A new horizontal mining plan view of a bottomless, column-free, segmental collapse safety construction device of the present invention is provided. Figure 2 This is a diagram showing the location of the reversing chamber before the adjustment. Figure 3 This is a schematic diagram of the overall cross-section; Figure 4 This is a schematic diagram of the internal structure of the air duct; Figure 5 This is a cross-sectional view of the exhaust hood; Figure 6 This is a schematic diagram of the internal structure of the cyclone separator; Figure 7 for Figure 5 Schematic diagram of the structure at point A in the middle; Figure 8 for Figure 5 Schematic diagram of the structure at point B; Figure 9 This is a flowchart of a safe construction method for segmented collapse without a bottom column.

[0020] Attached reference numerals: 1. Stage transport roadway; 2. Pass; 3. Pass connecting roadway; 4. Intake air shaft; 5. Intake air shaft connecting roadway; 6. Return air shaft; 7. Return air shaft connecting roadway; 8. Sectional access roadway connecting roadway; 9. Mining access roadway; 10. Cutting shaft; 11. Single-ended roadway; 12. Tunneling equipment; 13. Ventilation shaft; 14. Expansion joint; 15. Guide rail; 16. Fixing frame; 17. Air duct; 18. Exhaust hood; 19. Filter assembly; 20. Swirl tube; 21. Guide tube one; 22. Guide tube two; 23. Air supply tube; 24. Swirl plate; 25. Air outlet; 26. Guide plate; 27. Rotating shaft; 28. Push rod; 29. ​​Push plate; 30. Longitudinal connecting rod; 31. Transverse connecting rod; 32. Double-sided rack; 33. Motor; 34. Drive belt; 35. Arc-shaped toothed ring; 36. Fan. Detailed Implementation

[0021] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0022] like Figures 1-3 As shown, the present invention proposes a bottomless segmented caving safety construction device, which includes a reversing chamber set on one side of the upper horizontal chute 2 connecting roadway; as one embodiment, the existing mining structure includes a stage transport roadway 1, a chute connecting roadway 3, an intake air shaft 4, and a return air shaft 6. The chute 2 is connected to the stage transport roadway 1 via the chute connecting roadway 3. The intake air shaft 4 is connected to the segmented access roadway 8 via the intake air shaft connecting roadway 5. The return air shaft 6 is also connected to the segmented access roadway 8 via the return air shaft connecting roadway 7. The mining access roadway 9 is connected to the cutting shaft 10 via the segmented access roadway 8. The connection distance from the single-ended roadway 11, which is the first to be excavated in the inclined ramp connecting roadway, to the chute 2 is significantly shortened to within the range of 30-35 meters. At the connection point between the reversing chamber and the chute 2, an effective working distance of about 22 meters is reserved for the turning around of vehicles and unloading of slag after the connection is completed. The single-ended roadway 11, which is formed by the end excavation of the inclined ramp connecting roadway, is connected to the reversing chamber at its excavation end and is connected to the chute 2 through the reversing chamber. After the single-ended tunnel 11 is connected to the chute 2, the reversing chamber is configured to connect with and serve the transport vehicles, allowing the slag to be directly unloaded into the chute 2 through the reversing chamber, thus forming an independent slag discharge channel at this level. The construction equipment is described in detail below: In this embodiment, firstly, a main transport channel is established through stage transport roadway 1. After caving, the ore is lowered through ore pass 2 to the loading point of stage transport roadway 1. Ore pass connecting roadway 3 connects ore pass 2 and stage transport roadway 1, forming an ore transfer system. Regarding the ventilation system, fresh air enters through intake air shaft 4 and is introduced into a segmented horizontal roadway network through intake air shaft connecting roadway 5, specifically diverted to the connecting roadways 8 of each segmented approach. Waste air, generated at the mining face, is collected through the segmented approach connecting roadways 8 and discharged through the return air shaft connecting roadway 7 into the return air shaft 6, thus forming a complete ventilation loop. During the mining preparation stage, equipment and personnel enter the designated mining approach 9 through the segmented approach connecting roadway 8. Cutting shaft 10 serves as the free face and compensation space for initial blasting, and its design connects to the mining approach 9 through the segmented approach connecting roadway 8. In the actual mining process, the cutting face 10 or its alternative cutting roadway is used as the first free face. Blasting holes are constructed in the mining approach 9 for segmented micro-differential blasting. The collapsed ore is released at the bottom of the stope and transferred to the stage transport roadway 1 via the ore pass 2, and finally transported out by transport equipment. In addition, the reverse chamber is set on the side of the connecting roadway adjacent to the previous level ore pass 2, forming an optimized layout system consisting of the inclined ramp connecting roadway, the reverse chamber, and the ore pass 2. The single-ended roadway 11, which starts to be excavated from the new level inclined ramp connecting roadway, advances towards the reverse chamber. By controlling the breakthrough distance within the range of 35-30 meters, the length of the single-ended roadway 11 is significantly shortened.

[0023] like Figures 1-3 As shown, the construction equipment also includes a shortened penetration distance configured to facilitate the rapid formation of a circulating ventilation loop between the single-ended roadway 11 and the chute 2 after tunneling and blasting, a ventilation shaft 13 connected to the vertical single-ended roadway 11, and a guide rail 15 laid on the top of the roadway. In one embodiment, a telescopic pipe 14 is fixed to a slider inside the guide rail 15. One end of the telescopic pipe 14 is installed on the top of the tunneling equipment 12, and the other end is connected to a fixed frame 16 installed on the top of the ventilation shaft 13. The fixed frame 16 contains a filter mechanism and a vortex mechanism. The ventilation shaft 13 penetrates the mine shaft, providing circulating air, and further connects the intake shaft 4 and the mining access road 9 through the ventilation shaft 13. The construction equipment is described in detail below: In this embodiment, a guide rail 15 is laid on the top of the tunnel, and a telescopic pipe 14 is connected to the guide rail 15 via a slider. One end of the telescopic pipe 14 is installed on the top of the tunneling equipment 12, and the other end is connected to the ventilation shaft 13 via a fixed frame 16, forming a movable ventilation connection system. A filter mechanism and a vortex mechanism are installed inside the fixed frame 16. The filter assembly 19 is installed at the bottom of the air duct 17 to perform preliminary filtration of dust in the air. The fan 36 is installed on the inner wall of the air duct 17, so that the ventilation system can extend synchronously with the advance of the tunneling equipment 12, ensuring that the air outlet is always close to the working face.

[0024] like Figures 2-4As shown, the filtration mechanism also includes a tunneling device 12 installed at the working face of the single-ended tunnel 11 and a retractable air duct 17 installed in the middle of the single-ended tunnel 11. In one embodiment, the filter assembly 19 is installed at the bottom of the air duct 17, and a fan 36 is installed on the inner wall of the air duct 17 away from the filter assembly 19. The filtration mechanism is described in detail below: In this embodiment, a tunneling device 12 is deployed at the working face of the single-ended roadway 11, and a ventilation shaft 13 and a retractable ventilation duct 17 are installed in the roadway. When the tunneling device 12 performs blasting operations, the shortened roadway distance allows the working face to quickly form an effective circulating ventilation circuit through the chute 2. The polluted blasting smoke is quickly discharged through the ventilation system composed of the ventilation shaft 13 and the ventilation duct 17, and fresh air is replenished in time. After the roadway is completed, transport vehicles can directly unload the slag into the horizontal chute 2 through the reversing chamber, forming an independent slag discharge channel.

[0025] like Figures 1-8 As shown, the swirl assembly also includes a swirl tube 20 fixed in the middle of the inner wall of the air duct 17; in one embodiment, the inner wall of the swirl tube 20 is provided with an air outlet 25, a second guide tube 22 and a first guide tube 21 in sequence from bottom to top. An air supply tube 23 is fixed to the inner wall of the first guide tube 21 and the second guide tube 22. A swirl plate 24 is installed on the inner wall of the air supply tube 23. The first guide tube 21 and the second guide tube 22 are provided with multiple through holes with inclined angles. The swirl assembly also includes an exhaust hood 18 for discharging internal air. Multiple linearly arrayed guide plates 26 slide on the inner wall of the exhaust hood 18. A rotating shaft 27 and a push rod 28 are fixed to both ends of each guide plate 26. The rotating shaft 27 is located at the middle of both ends of the guide plate 26, and the push rod 28 is located at the upper ends of both ends of the rotating shaft 27. A push plate 29 slides on the outer wall of the push rod 28. The outer wall of the push plate 29 is connected by a longitudinal connecting rod 30. A transverse connecting rod 31 is fixed to one end of the longitudinal connecting rod 30, and a double-sided rack 32 is fixed to the middle of the transverse connecting rod 31. A motor 33 is fixed inside the exhaust hood 18. A transmission belt 34 is provided at the output end of the motor 33. The transmission belt 34 consists of two concave pulleys and a mating belt. Arc-shaped toothed rings 35 are fixed to the top of each of the two concave pulleys, and the two arc-shaped toothed rings 35 respectively mesh with the outer walls of the double-sided rack 32. The swirl assembly will be described in detail below: In this embodiment, the swirl tube 20 is fixed in the middle of the inner wall of the air duct 17, and the air vent 25, the second guide tube 22, and the first guide tube 21 are arranged sequentially from bottom to top inside the duct. The first guide tube 21 and the second guide tube 22 are provided with air supply tubes 23, and the swirl plate 24 installed on the inner wall of the air supply tube 23 causes the air to rotate and flow. The multiple inclined through holes inside the first guide tube 21 and the second guide tube 22 further enhance the swirling effect of the air and increase the air passage speed. In addition, the start motor 33 drives the transmission belt 34 to run. At this time, the transmission belt 34 can drive the arc-shaped toothed rings 35 at both ends to rotate synchronously. Then, the two arc-shaped toothed rings 35 drive the double-sided rack 32 to move back and forth. Then, the double-sided rack 32 drives the transverse connecting rod 31 and the longitudinal connecting rod 30 to move back and forth. During this process, the movement of the longitudinal connecting rod 30 drives the movement of multiple push plates 29. The movement of the push plates 29 pulls the push rod 28 to move. Then, the movement of the push rod 28 drives the guide plate 26 to rotate and adjust around the rotating shaft 27 as the center. This causes the air to swing and be discharged evenly, controlling the air outlet 25 to swing in a sweeping manner, agitating the air and accelerating dilution.

[0026] like Figures 1-9 As shown, the present invention also provides a safe construction method for segmented collapse without a bottom column, the method comprising the following steps: S1. Optimize the tunnel design and position the reversing chamber of the new level on the side of the connecting tunnel adjacent to the previous level chute 2; S2. Starting from the new horizontal inclined roadway connecting roadway, excavate the single-ended roadway 11 towards the reversing chamber, controlling its excavation distance within the range of 35-30 meters, until it is connected to the chute 2; S3. During the tunneling process, the ventilation and dust removal system is activated to supply fresh air to the working face through the ventilation shaft 13 and the telescopic pipe 14, and the dust on the working face is treated by the filtration and cyclone mechanism. S4. After the single-ended tunnel 11 is connected to the chute 2, the reverse chamber is used as a passage to directly unload the slag into the horizontal chute 2 for slag removal. S5. Based on the progress of the working face, adjust the position of the telescopic pipe 14 through the guide rail 15 and the fixed frame 16, and adjust the angle of the guide plate 26 to control the air supply direction.

[0027] Specifically, the roadway layout was first optimized by precisely positioning the reversing chamber of the new level on the side of the connecting roadway adjacent to the chute 2 of the previous level. This ensured that the connection distance from the single-heading roadway 11, which starts excavation from the connecting roadway of the new level, to the chute 2 was controlled within the range of 35-30 meters. At the connection point between the reversing chamber and the chute 2, an effective working distance of 22 meters was reserved for subsequent vehicle turning and slag unloading operations.

[0028] During the tunneling construction phase, the single-ended tunnel 11 is excavated from the end of the inclined ramp connecting tunnel towards the reversing chamber. Guide rails 15 are laid on the top of the tunnel, and telescopic pipes 14 are connected to the guide rails 15 through sliders. One end of the telescopic pipe is installed on the top of the tunneling equipment 12, and the other end is connected to the ventilation shaft 13 through the fixing frame 16. As the tunneling equipment 12 advances, the telescopic pipes 14 extend synchronously along the guide rails 15 to ensure that the air outlet is always close to the working face.

[0029] The ventilation and dust removal system operates synchronously during the tunneling process. After the fan 36 is started, the airflow enters the filter assembly 19 through the air duct 17 for preliminary dust removal. Then the airflow enters the vortex 20 and is guided by the first guide tube 21 and the second guide tube 22. Under the action of the vortex plate 24, a rotating airflow is formed to achieve secondary purification. The purified airflow is discharged from the exhaust hood 18 through the air supply duct 23.

[0030] The starter motor 33 drives the transmission belt 34 to run, which drives the two arc-shaped toothed rings 35 to rotate synchronously. The arc-shaped toothed rings 35 mesh with the double-sided rack 32, driving the double-sided rack 32 to reciprocate. Through the transmission of the transverse connecting rod 31 and the longitudinal connecting rod 30, the push plate 29 is pushed to move, and then the push rod 28 drives the guide plate 26 to rotate around the rotating shaft 27, so as to achieve precise control of the air outlet direction.

[0031] Once the single-ended roadway 11 is connected to the chute 2, the reversing chamber is immediately activated as a slag removal channel. Transport vehicles unload slag directly into the horizontal chute 2 through the reversing chamber, forming an independent slag removal system. At the same time, due to the shortened roadway distance, a circulating ventilation loop can be quickly formed through the chute 2 after blasting, and the blasting fumes are quickly discharged through the ventilation system consisting of the ventilation shaft 13 and the ventilation duct 17.

[0032] The above specific embodiments are merely several optional embodiments of the present invention. Based on the technical solutions of the present invention and the relevant teachings of the above embodiments, those skilled in the art can make various alternative improvements and combinations to the above specific embodiments.

Claims

1. A safety construction device for segmented collapse without a bottom column, characterized in that, Based on the existing mining structure, a ramp connecting roadway is formed at the new level, a chute (2) is set at the previous level, and a reversing chamber is set at the new level. The existing mining structure includes a stage transport roadway (1), a chute connecting roadway (3), an intake air shaft (4), and a return air shaft (6). The chute (2) is connected to the stage transport roadway (1) through the chute connecting roadway (3). The intake air shaft (4) is connected to the segmented access roadway (8) through the intake air shaft connecting roadway (5). The return air shaft (6) is also connected to the segmented access roadway (8) through the return air shaft connecting roadway (7). The mining roadway (9) is connected to the cutting shaft (10) through the segmented access roadway (8). The reverse chamber is located on the side of the connecting roadway adjacent to the chute (2). The connection distance from the single-head roadway (11) at the start of the inclined roadway to the chute (2) is greatly shortened to within 35-30 meters. At the connection point between the reversing chamber and the chute, an effective working distance of approximately 22 meters is reserved for vehicle turning around and unloading operations after the connection is completed. The single-ended roadway (11) formed by the end excavation of the inclined ramp connecting roadway connects to the reversing chamber at its excavation end point and is connected to the chute (2) through the reversing chamber.

2. The column-free segmented collapse safety construction equipment according to claim 1, characterized in that, The shortened penetration distance enables the single-ended roadway (11) to quickly form a circulating ventilation loop with the chute (2) after tunneling and blasting. The single-ended roadway (11) is connected to the vertically set ventilation shaft (13), and the ventilation shaft (13) further connects the intake shaft (4) with the mining access road (9).

3. The column-free segmented collapse safety construction equipment according to claim 2, characterized in that, After the single-ended tunnel (11) is connected to the chute (2), the reversing chamber is configured to connect with and serve the transport vehicle, so that the slag can be directly unloaded into the chute (2) through the reversing chamber, thereby forming an independent slag discharge channel at this level.

4. The column-free segmented collapse safety construction equipment according to claim 3, characterized in that, The construction equipment also includes a tunneling device (12) installed at the working face of the single-ended tunnel (11) and a retractable ventilation duct (17) installed in the middle of the single-ended tunnel (11).

5. The column-free segmented collapse safety construction equipment according to claim 4, characterized in that, The construction equipment also includes a guide rail (15) laid on the top of the tunnel. The guide rail (15) has a sliding block with a telescopic tube (14) fixed inside. One end of the telescopic tube (14) is installed on the top of the tunneling equipment (12), and the other end is connected to a fixed frame (16) set on the top of the ventilation shaft (13). The fixed frame (16) is equipped with a filter mechanism and a vortex mechanism.

6. The column-free segmented collapse safety construction equipment according to claim 5, characterized in that, The filtration mechanism includes an air duct (17) for supplying air and a filter assembly (19) for filtering air. The filter assembly (19) is installed at the bottom of the air duct (17), and a fan (36) is installed on the inner wall of the air duct (17) away from the filter assembly (19).

7. The column-free segmented collapse safety construction equipment according to claim 5, characterized in that, The swirl assembly includes a swirl cylinder (20) fixed in the middle of the inner wall of the air duct (17). The inner wall of the swirl cylinder (20) is equipped with an air outlet (25), a second guide cylinder (22) and a first guide cylinder (21) from bottom to top. An air supply duct (23) is fixed on the inner wall of the first guide cylinder (21) and the second guide cylinder (22). A swirl plate (24) is installed on the inner wall of the air supply duct (23). The first guide cylinder (21) and the second guide cylinder (22) are both provided with multiple through holes with inclined angles.

8. The column-free segmented collapse safety construction equipment according to claim 7, characterized in that, The swirl assembly also includes an exhaust hood (18) for discharging internal air. Multiple guide plates (26) arranged in a linear array slide on the inner wall of the exhaust hood (18). A rotating shaft (27) and a push rod (28) are fixed at both ends of each guide plate (26). The rotating shaft (27) is located at the middle of both ends of the guide plate (26), and the push rod (28) is located at the upper ends of both ends of the rotating shaft (27). A push plate (29) slides on the outer wall of the push rod (28). The outer wall of the push plate (29) is connected by a longitudinal connecting rod (30). The longitudinal connecting rod (30) is connected to a transverse connecting rod (31) at one end. A double-sided rack (32) is fixed in the middle of the transverse connecting rod (31). A motor (33) is fixed inside the exhaust hood (18). A transmission belt (34) is provided at the output end of the motor (33). The transmission belt (34) consists of two concave pulleys and a belt that matches them. An arc-shaped toothed ring (35) is fixed on the top of each of the two concave pulleys. The two arc-shaped toothed rings (35) are respectively meshed on both sides of the outer wall of the double-sided rack (32).

9. The column-free segmented collapse safety construction equipment according to claim 5, characterized in that, The ventilation shaft (13) runs through the interior of the mine and provides circulating air.

10. A method for safe construction of subgrade caving without a bottom column, applied to the subgrade caving safety construction equipment described in any one of claims 1-9, characterized in that, The method includes the following steps: S1. Optimize the tunnel design and position the reversing chamber of the new level on the side of the connecting tunnel adjacent to the previous level chute (2); S2. Starting from the new horizontal inclined roadway connecting roadway, excavate the single-headed roadway (11) towards the reverse chamber, controlling its excavation distance within the range of 35-30 meters, until it is connected to the chute; S3. During the tunneling process, the ventilation and dust removal system is activated to supply fresh air to the working face through the ventilation shaft (13) and the telescopic pipe (14), and the dust on the working face is treated by the filtration and vortex mechanism. S4. After the single-ended roadway (11) is connected to the chute, the reverse chamber is used as a passage to directly unload the slag into the horizontal chute for slag removal. S5. According to the progress of the working face, adjust the position of the telescopic pipe (14) through the guide rail (15) and the fixed frame (16), and adjust the angle of the guide plate (26) to control the air supply direction.

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