Upward horizontal subsection continuous mining and continuous filling mining method for steeply inclined short-distance coal group

Abstract

An upward horizontal subsection continuous mining and continuous filling mining method for a steeply-inclined close-distance coal seam group comprises the steps that the arrangement mode of a working face system is determined according to the distribution condition of a steeply-inclined close-distance coal seam, and the interval coal pillar width is determined according to the coal seam overlying rock pressure, the pressure-bearing coal pillar ultimate bearing capacity and the surrounding rock stability requirement; dividing the coal seam into a plurality of horizontal strips along the inclined direction, and horizontally dividing the strips into a plurality of narrow strips; the high-position narrow strip and the low-position narrow strip are communicated through a chamber arranged in the main haulage roadway and a finger-shaped connection roadway starting from the chamber; excavating equipment is arranged in the working face by adopting a strike longwall method, and narrow-strip-type graded mining and filling are carried out. Safe, green and efficient mining of the steeply inclined short-distance coal seam group is realized through a continuous mining and continuous filling process, improvement of working face system arrangement, optimization of a stoping process and control of surrounding rock deformation.

Description

Technical Field

[0001] The present invention belongs to the technical field of coal mining, and relates to a method for mining a steeply inclined coal seam, and in particular to a method for upward horizontal segmented continuous mining and filling of a steeply inclined close-range coal group. Background Art

[0002] Steeply inclined coal seams, a type of coal seam with unique burial conditions, have complex occurrence and coal-forming environments, making safe mining challenging. They are recognized by the mining community both domestically and internationally as difficult to mine. Steeply inclined coal seams are widely distributed in my country, with proven reserves of approximately 1,800 to 3,600 Gt and production of approximately 1.5 to 3 Gt, accounting for 10-20% and 5-8% of national coal reserves and production, respectively. Mining of steeply inclined coal seams in my country began in the 1950s, with the introduction of non-mechanized mining methods such as silo mining, reverse bench mining, and horizontal slicing. From the 1960s to the mid-to-late 1980s, conventional mechanized mining methods for steeply inclined coal seams, represented by pseudo-inclined flexible shield mining, emerged and gradually matured. From the late 1980s to the early 21st century, various mining areas successfully developed strike longwall comprehensive mechanized mining, strike longwall comprehensive mechanized top coal caving mining, and horizontal segmented comprehensive mechanized top coal caving mining. Among them, the steeply inclined longwall comprehensive mechanized coal mining method is applicable to coal seams with angles mostly below 60° and locally reaching 62°, which solves the mining problem of steeply inclined thin and medium-thick single coal seams; the steeply inclined longwall comprehensive mechanized top coal caving mining method is applicable to coal seams with thickness between 4 and 10 meters and inclination angle less than 60°, which solves the mining problem of steeply inclined thick coal seams; the horizontal segmented comprehensive mechanized top coal caving mining method is applicable to coal seams with thickness greater than 10 meters, which solves the mining problem of steeply inclined extra-thick coal seams.

[0003] However, for steeply inclined, closely spaced coal seams, particularly those with individual seams 4-10 meters thick and intervening rock layers less than 10 meters thick, the aforementioned mining methods can lead to interconnectedness between adjacent stoping spaces due to factors such as seam inclination, thickness, and interlayer spacing, potentially inducing complex dynamic hazards in the mining area. Furthermore, the large-scale production and utilization of coal resources generates significant amounts of solid waste, including gangue. Statistics show that my country currently has a cumulative gangue stockpile exceeding 60 Gt, resulting in over 1,700 gangue heaps. With the advent of the "Two Mountains" theory and growing public awareness of environmental protection, environmental standards and requirements for mining development are becoming increasingly stringent. The discharge of gangue and the resulting gangue heaps pose significant negative impacts on the green development of mining areas. Negative effects such as environmental pollution are becoming increasingly unacceptable and may even threaten the viability of coal mines. Therefore, to address the challenges of steeply inclined, closely spaced coal seams and gangue disposal, the continuous mining and backfilling mining method has been introduced.

[0004] Continuous mining and backfilling technology utilizes a longwall mining system, replacing shearers with tunneling machines (TMMs) or continuous miners for coal mining. This involves excavating a connecting tunnel between the haul tunnel and the return air tunnel at the working face using a TMM or continuous miner for shortwall excavation. After the tunnel is excavated, it is backfilled using cemented backfilling technology. Simultaneously, another tunnel is excavated, achieving a parallel operation of "tunnel excavation and backfilling" within the working face. However, in steeply inclined coal seams, the continuous mining and backfilling method presents challenges such as equipment slippage and difficulty transporting materials, limiting its application in these areas. Therefore, innovation in this method is urgently needed. Summary of the Invention

[0005] In order to solve the shortcomings of the existing steeply inclined coal seam mining technology and gangue treatment technology, the present invention aims to provide a method for upward horizontal segmented continuous mining and filling of steeply inclined and close-range coal seam groups. By improving the layout of the continuous mining and filling working face system and optimizing the mining and filling process, the purpose of controlling surrounding rock deformation and disposing of gangue solid waste can be achieved.

[0006] The present invention provides a method for upward horizontal segmented continuous mining and filling of a group of steeply inclined and closely spaced coal seams, comprising:

[0007] The working face system layout is determined based on the distribution of steeply inclined and closely spaced coal seams. The distance between the mining branch tunnel and the filling branch tunnel, i.e., the width of the interval coal pillar, is preliminarily determined based on the overlying rock pressure of the coal seams, the ultimate bearing capacity of the pressure-bearing coal pillar, and the surrounding rock stability requirements.

[0008] Select working face parameters, including cross-sectional shape and size of branch tunnels, based on coal mine output, coal seam thickness, and mining equipment parameters;

[0009] Based on the width of the interval coal pillars, the coal seam is divided into a plurality of horizontal strips along the inclination, with every two adjacent strips forming a stage; the strips in each stage are further divided horizontally into a plurality of narrow strips, i.e., each stage includes a plurality of low-level narrow strips and a plurality of high-level narrow strips;

[0010] A return air tunnel and a transport tunnel are arranged parallel to the coal seam direction in the upper and lower coal seams respectively; a return air uphill tunnel is arranged parallel to the coal seam inclination between the return air tunnel and the transport tunnel; a transport uphill tunnel is arranged at a certain angle to the coal seam inclination at the other end of the transport tunnel; a return air stone gate is arranged at a certain angle to the coal seam inclination at the other end of the return air tunnel; a turning chamber is arranged at the intersection of the transport uphill tunnel and the return air stone gate;

[0011] In each stage, a low-level finger-shaped connecting tunnel intersecting chamber is arranged in the transport uphill, and starting from the chamber, a low-level finger-shaped connecting tunnel connected to the low-level narrow strip is set; starting from the turning chamber, a transport stone gate is horizontally set, and a high-level finger-shaped connecting tunnel intersecting chamber is set at the end of the transport stone gate; starting from the high-level finger-shaped connecting tunnel intersecting chamber, a high-level finger-shaped connecting tunnel connected to the high-level narrow strip is set;

[0012] The longwall method is used to arrange mining equipment in the working face, and the continuous mining and filling method is adopted to carry out coal mining in the working face.

[0013] Furthermore, when mining coal on the working face, narrow strips are mined and filled in batches; in each of the stages, after the first low-level narrow strip is mined, the first high-level narrow strip is mined, and the first low-level narrow strip is filled at the same time; then the second low-level narrow strip is mined, and the first high-level narrow strip is filled at the same time; and so on, the mining and filling of the entire working face are completed.

[0014] Furthermore, when determining the width of the interval coal pillars, the width range of the interval coal pillars is first determined according to the following formula:

[0015]

[0016] Where w is the width of the interval coal pillar, k is the safety factor (generally 1.5 to 2.5), γ is the bulk density of the overlying rock layer, H is the depth of the coal seam, α is the inclination angle of the coal seam, and σ is the relative humidity. c is the uniaxial compressive strength of coal, h is the thickness of the coal seam;

[0017] Secondly, numerical simulation is used to select the optimal interval coal pillar width according to the stability of the surrounding rock within the preliminarily determined interval coal pillar width range.

[0018] Furthermore, a rectangular cross-section is selected for the excavation branch tunnel; after the cross-section of the excavation branch tunnel is determined, the width of the excavation branch tunnel is determined according to the parameters of the mining equipment and the thickness of the coal seam; and the height of the excavation branch tunnel is determined according to the expected output and the width of the excavation branch tunnel;

[0019] The output calculation formula is:

[0020] A0=L×S×γ×n÷10000

[0021] Where A0 is the annual output; L is the annual excavation length of the tunnel, S is the cross-sectional area of ​​the excavation branch tunnel, γ is the bulk density of coal, and n is the effective construction rate.

[0022] Furthermore, the horizontal distance between the high-level finger-shaped connecting tunnel intersection chamber and the low-level finger-shaped connecting tunnel intersection chamber and the strip end is equal.

[0023] Furthermore, local ventilation is adopted before the narrow strip is excavated, and full wind pressure ventilation is implemented after the narrow strip is excavated and connected to the return air uphill: fresh air flows from the transport main tunnel through the transport uphill, low-level or high-level finger-shaped connecting tunnel to the working face; polluted air flows from the working face to the return air uphill, and then through the return air stone gate to the return air main tunnel.

[0024] Furthermore, in the working face system, a transportation system is arranged, and the transportation routes are as follows:

[0025] Coal transportation route: working face → low-level or high-level finger-shaped connecting tunnel → transportation uphill → transportation main tunnel;

[0026] Auxiliary transport routes to the working face: transport main tunnel → transport uphill → low-level or high-level finger-shaped connecting tunnel → working face;

[0027] The mining equipment is transported from the low narrow strip to the high narrow strip route: low narrow strip → low finger connecting tunnel → transport up the mountain → high finger connecting tunnel → high narrow strip.

[0028] Furthermore, when mining narrow strips, starting from the intersecting chamber of the low-level finger-shaped connecting tunnel, the low-level finger-shaped connecting tunnel is excavated to the low-level narrow strip mining working face; narrow strip mining and bottom pulling are carried out; at the same time, starting from the intersecting chamber of the high-level finger-shaped connecting tunnel, the high-level finger-shaped connecting tunnel is excavated to the high-level narrow strip mining working face; after the low-level narrow strip is mined, the mining equipment is moved to the corresponding high-level narrow strip for mining; at the same time, the entire space of the mined strip is filled with paste.

[0029] Furthermore, the roof of the goaf is managed by the full filling method, and airborne front exploration beams plus a small number of anchor rods are used as temporary support in narrow strips.

[0030] The present invention is beneficial in that:

[0031] 1. The continuous mining and filling technology is applied to the mining of steeply inclined and close-range coal seams. Through the supporting effect of the filling body, it effectively solves the problems of mutual influence between the upper and lower working faces of the steeply inclined and close-range coal seams, deformation of the surrounding rock during mining, and splashing of waste rock. At the same time, the parallel mining and filling mode is used to improve production efficiency, and to a certain extent, safe and efficient mining of such coal seams is achieved.

[0032] 2. The upward horizontal segmented mining method is adopted to achieve horizontal mining of the working face, effectively avoiding problems such as difficulty in working face equipment stability and difficulty in pedestrian material transportation caused by the steep inclination of the coal seam.

[0033] 3. Through the filling method, the gangue produced in the coal mine production process is prepared into a paste material and filled in the goaf, solving the problems of difficult and high processing costs of gangue, and promoting green production of coal mines.

[0034] 4. Through the continuous mining and filling process, the coal pillar is replaced, which improves the resource recovery rate and solves the problem of large waste of resources in the remaining coal pillars. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] For a more complete understanding of the present invention, reference will now be made to the following description taken in conjunction with the accompanying drawings, in which:

[0036] Figure 1 This is a schematic diagram of the layout of the upward horizontal segmented continuous mining and filling mining tunnels for a group of steeply inclined and closely spaced coal seams according to the present invention;

[0037] Figure 2 This is a cross-sectional view of the arrangement of the upward horizontal segmented continuous mining and filling working face of a group of steeply inclined and closely spaced coal seams according to the present invention;

[0038] Figure 3 This is a top view of the upward horizontal segmented continuous mining and filling working face layout of the steeply inclined and close-distance coal seam group described in the present invention.

[0039] In the figure: 1. Return air main tunnel; 2. Return air uphill; 3. Filling pipeline; 4. Filling branch tunnel; 5. Transport main tunnel; 6. Coal mining branch tunnel; 7. Isolation device; 8. Transport uphill; 9. Low-level finger-shaped connecting tunnel; 10. Intersecting chamber of low-level finger-shaped connecting tunnel; 11. High-level finger-shaped connecting tunnel; 12. Intersecting chamber of high-level finger-shaped connecting tunnel; 13. Turning chamber; 14. Return air stone gate; 15. Rock layer; 16. Coal seam; 17. Transport stone gate. DETAILED DESCRIPTION

[0040] To clearly illustrate the purpose, technical details, and effective applications of the present invention and to facilitate understanding and implementation by those skilled in the art, the present invention will be further described in detail below in conjunction with the embodiments and accompanying drawings. Obviously, the embodiments described herein are only for the purpose of illustrating and explaining the present invention and are not intended to limit the present invention.

[0041] The present invention provides a method for upward horizontal segmented continuous mining and filling of a group of steeply inclined close-range coal seams, which is suitable for steeply inclined medium-thick coal seams, especially for steeply inclined medium-thick coal seams with a coal seam inclination angle greater than 45° and a coal seam thickness of 1.5 to 3.5 meters.

[0042] To illustrate the method of the present invention, a specific situation of a coal mine is used as an example for detailed description. The annual output of the mine is tentatively set at 100,000 tons. It is known that the annual production time is 330 days, the coal seam is 3 meters thick, the coal seam inclination is 54 degrees, the average burial depth of the coal seam is about 400 meters, and the bulk density of the overlying rock layer is about 25KN / m 3 The uniaxial compressive strength of coal is about 5MPa, belonging to a group of steeply inclined, close-range, medium-thick coal seams.

[0043] Reference Figure 1 、 Figure 2 , the mining method specifically comprises the following steps:

[0044] Step S01: Determine the working face system layout according to the distribution of steeply inclined and closely spaced coal seams, including the width of the interval coal pillars and working face parameters.

[0045] Step S101: Determine the width of the interval coal pillars according to the pressure of the overlying rock strata above the coal seam, the ultimate bearing capacity of the pressure-bearing coal pillars, and the stability requirements of the surrounding rock.

[0046] Specifically, first determine the width range of the interval coal pillars according to the following formula:

[0047]

[0048] Where w is the width of the interval coal pillar, k is the safety factor (generally 1.5 to 2.5), γ is the bulk density of the overlying rock layer, H is the depth of the coal seam, α is the inclination angle of the coal seam, and σ is the relative humidity. c is the uniaxial compressive strength of coal, and h is the thickness of the coal seam.

[0049] Specifically in this embodiment, considering that the safety factor k is 1.5 to 2.5, it can be preliminarily determined through calculation that the width of the interval coal pillars ranges from 8 to 12 m.

[0050] The above formula fully considers the pressure of the overlying rock strata of the coal seam and the ultimate bearing capacity of the pressure-bearing coal pillar, determines the safe and reliable width of the interval coal pillar, and provides a basis for subsequent mining and filling mode.

[0051] Secondly, numerical simulation is used to select the optimal interval coal pillar width according to the stability of the surrounding rock within the preliminarily determined interval coal pillar width range.

[0052] Specifically, in this example, FLAC3D finite-difference numerical simulation software was used to compare the surrounding rock deformation and stress of coal pillars spaced 8 to 12 meters apart. The results showed that the surrounding rock stability of the 12-meter interval coal pillars was higher. Based on the above, the width of the interval coal pillars can be determined to be 12 meters.

[0053] Step S102: Select working face parameters, including cross-sectional shape and size of the excavation branch tunnel, based on coal mine output, coal seam thickness, mining equipment, etc.

[0054] In view of the difficulty in constructing special-shaped tunnel sections, the poor stability of the surrounding rock, the complex support method, and the need for special tunneling equipment, it is preferred to use a rectangular cross-section for the tunneling branch.

[0055] After determining the cross-section of the excavation branch tunnel, the width of the excavation branch tunnel is determined based on the mining equipment parameters and coal seam thickness.

[0056] Specifically in this example, an LWS600 continuous miner (3.6m width, 400-450m monthly excavation progress) was selected as the excavation equipment. Considering the coal seam thickness of 3m, excavation requires breaking a certain roof and floor, so the width of the excavation branch tunnel is determined to be 4m.

[0057] The height of the branch tunnel is determined based on the expected output and the width of the branch tunnel. The output calculation formula is:

[0058] A0=L×S×γ×n÷10000

[0059] Where A0 is the annual output; L is the annual excavation length of the tunnel, S is the cross-sectional area of ​​the excavation branch tunnel, γ is the bulk density of coal, and n is the effective construction rate (generally taken as 0.9).

[0060] For the coal mine described in the embodiment, with an annual output of 100,000 tons, the height of the branch tunnel (mining height) can be calculated according to the above formula:

[0061] h=100000÷4÷1.35÷0.9÷12=4.3

[0062] If you want to reach full production, the height of the branch tunnel should be greater than 4.3. Considering a certain production surplus coefficient and breaking a certain roof and floor, the height of the branch tunnel can be determined to be 5m.

[0063] Step S103: Based on the interval coal pillar width determined in step S101 and the working face parameters determined in step S102, the coal seam is divided into horizontal strips along the inclination, and mining tunnels are arranged according to the inclination of the coal seam and the climbing ability of the equipment.

[0064] First, based on the width of the interval coal pillars, the steeply inclined coal seam is horizontally divided into multiple strips along the inclination, with every two adjacent strips forming a stage; and based on the working face parameters, the strips in each stage are further horizontally divided into several narrow strips.

[0065] See also Figure 1-3 In this embodiment, two adjacent strips include four high-level narrow strips from top to bottom: A1, A2, A3, A4, and four low-level narrow strips: B1, B2, B3, B4, and the strike length of each strip is 200m.

[0066] Secondly, the mining tunnels are arranged according to the inclination of the coal seam and the climbing ability of the equipment.

[0067] A return air main tunnel 1 is arranged parallel to the strike in the coal seam above the highest narrow strip, and a transport main tunnel 5 is arranged parallel to the strike in the coal seam below the lowest narrow strip; a return air uphill tunnel 2 is arranged parallel to the inclination of the coal seam in the coal seam floor, and the return air uphill tunnel 2 intersects with the return air main tunnel 1 and the transport main tunnel 5; a transport uphill tunnel 8 is arranged at a certain angle to the horizontal plane in the coal seam floor, and intersects with the transport main tunnel 5; a return air stone gate 14 is arranged at a certain angle to the horizontal plane, connected to the return air main tunnel 1, and connected to the transport uphill tunnel 8, and a turning chamber 13 is provided at the intersection of the return air stone gate 14 and the transport uphill tunnel 8.

[0068] Reference Attachment Figure 1-3 In this embodiment, a return air tunnel 1 is arranged parallel to the strike in the coal seam above the narrow strip A1; a transport tunnel 5 is arranged parallel to the strike in the coal seam below the narrow strip B4. The horizontal distance between the narrow strip and the tunnel is 10m. A return air uphill 2 is arranged in the coal seam floor, parallel to the coal seam inclination, and 10m horizontally away from the coal seam floor. A transport uphill 8 is arranged in the coal seam floor, extending upward at an angle of 20° to the horizontal plane. A return air stone gate 14 arranged at an angle of 20° to the horizontal plane is connected to the return air tunnel 1 and communicates with the transport uphill 8. A turning chamber 13 is provided at the intersection of the two to ensure full wind pressure ventilation in the transport uphill 8. The transport uphill 8 is connected to the transport tunnel 5 and extends upward at an angle of 20° to the horizontal plane.

[0069] A low-level finger-shaped connecting tunnel intersecting chamber 10 is arranged in the transport uphill 8, and starting from the chamber, a low-level finger-shaped connecting tunnel 9 connected with each excavation branch tunnel at a low position in the said stage is set; starting from the said turning chamber 13, a horizontally arranged transport stone gate 17 is set, and a high-level finger-shaped connecting tunnel intersecting chamber 12 is set in the said transport stone gate 17; starting from the said high-level finger-shaped connecting tunnel intersecting chamber 12, a high-level finger-shaped connecting tunnel 11 connected with each excavation branch tunnel at a high position in the said stage is set; the high-level finger-shaped connecting tunnel intersecting chamber 12 and the low-level finger-shaped connecting tunnel intersecting chamber 10 are at the same horizontal distance from the end of the strip.

[0070] Reference Attachment Figure 1-3In this embodiment, two chambers are arranged in the transport uphill 8, namely a low-level finger-shaped connecting tunnel intersection chamber 10 and a turning chamber 13, with vertical distances of 21m and 42m from the main transport tunnel 5, respectively. Four low-level finger-shaped connecting tunnels 9 leading to four low-level narrow strips are arranged in the low-level finger-shaped connecting tunnel intersection chamber 10, which is 21m vertically away from the main transport tunnel 5. In the turning chamber 13, which is 42m vertically away from the main transport tunnel 5, a transport stone gate 17 is arranged horizontally toward the coal seam, and four high-level finger-shaped connecting tunnels 11 leading to four high-level narrow strips are arranged. The arrangement of the transport stone gate 17 must ensure that the high-level finger-shaped connecting tunnel intersection chamber 12 at the intersection of the low-level finger-shaped connecting tunnel intersection chamber 10 and the four high-level finger-shaped connecting tunnels 11 is at the same horizontal distance from the coal seam. The turning chamber 13 is connected to the return air tunnel 1 through a return air stone door 14 with a horizontal angle of 20 degrees. The vertical distance between the transport tunnel 5 and the return air tunnel 1 is about 52m.

[0071] After the arrangement of the mining tunnel is completed, the ventilation system of the mining method provided by the present invention is: local ventilation is adopted before the narrow strip of the working face is excavated, and full wind pressure ventilation is implemented after the narrow strip of the working face is excavated and connected to the return air up the mountain 2.

[0072] Among them, the full-pressure ventilation means: fresh air flows from the transport tunnel 5 through the transport uphill 8, finger-shaped connecting tunnels 9 and 11 to the working face; polluted air flows from the working face to the return air uphill 2, and then through the return air stone gate 14 to the return air tunnel 1.

[0073] The specific ventilation routes are as follows:

[0074] ① Fresh air flow route: transport main tunnel 5 → transport uphill 8 → finger-shaped connecting tunnels 9, 11 → working face.

[0075] ② Polluted air route: working face → return air uphill 2 → return air stone gate 14 → return air main tunnel 1.

[0076] Step S02: excavate the tunnel according to the working face system layout determined in step S01, and adopt permanent support to provide support.

[0077] Among them, the transport main tunnel 5, transport stone gate 17, transport uphill 8, return air main tunnel 1, return air stone gate 14, return air uphill 2, and finger-shaped connecting tunnels 9 and 11 all use permanent support.

[0078] The permanent support may be anchor rods and / or anchor cables. Step S03: Arrange a transportation system in the working face system determined in step S01.

[0079] Specifically, in this embodiment, the continuous miner is equipped with a collecting head mechanism and a scraper conveyor. As the continuous miner cuts, coal falls into the collecting head mechanism. The continuously operating rake claws rake the coal into the scraper conveyor, where it is then transported by a belt conveyor through the finger-shaped connecting tunnels 9 and 11, uphill transport 8, and finally to the main transport tunnel 5.

[0080] The transport routes are as follows:

[0081] ① Coal transportation route: working face → finger-shaped connecting tunnels 9 and 11 → transport uphill 8 → transport main tunnel 5;

[0082] ② Auxiliary transport route to the working face: transport main tunnel 5 → transport uphill 8 → finger-shaped connecting tunnels 9 and 11 → working face;

[0083] ③ The route for transporting continuous miners from the low-level working face to the high-level working face: low-level working face → low-level finger-shaped connecting tunnel 9 → transport uphill 8 → high-level finger-shaped connecting tunnel 11 → high-level working face.

[0084] Step S04: Use a continuous miner or a roadheader to mine in the working face, adopt the longwall method, and mine and fill in narrow strips in batches; in every two adjacent strips, after the first low-level narrow strip is mined, the first high-level narrow strip is mined, and the first low-level narrow strip is filled at the same time; and so on, to complete the mining and filling of the entire working face.

[0085] Specifically in this embodiment,

[0086] Step S401: Starting from the low-level finger-shaped connecting tunnel intersecting chamber 10, excavating the low-level finger-shaped connecting tunnel 9 to the coal mining working face; and permanently supporting the low-level finger-shaped connecting tunnel 9.

[0087] Step S402: Conduct narrow strip mining and bottom mining. A continuous miner is used to excavate a 4m×4m strip along the roof, and bottom mining is performed to recover the 1m thick bottom coal in the floor. Simultaneously, starting from the intersecting chamber 12 of the high-level finger-shaped connecting tunnel, a high-level finger-shaped connecting tunnel 11 is excavated to the coal mining face, and the high-level finger-shaped connecting tunnel 11 is permanently supported.

[0088] Step S403: After the low narrow strip is mined, the continuous miner moves to the corresponding high narrow strip for mining; at the same time, the paste is used to fill the entire space of the mined strip.

[0089] From the low narrow strip, through the low finger connecting tunnel 9, transport up the mountain 8, and the high finger connecting tunnel 11, move to the next high narrow strip 12m apart to continue mining; at the same time, the mined low narrow strip is sealed and isolated at both ends using a lightweight isolation bracket, and the entire space of the mined strip is filled with paste.

[0090] Step S404: After the filling body of the low-level goaf strip solidifies for 28 days, a second round of filling mining is carried out to mine the second low-level narrow strip and completely fill the first high-level narrow strip; and so on until all are mined; the interval between each mining round is not less than 28 days.

[0091] The order of mining narrow strips is: B4→A4→B3→A3→B2→A2→B1→A1.

[0092] The roof of the goaf is managed by the full filling method, and airborne front exploration beams plus a small amount of anchor rods are used as temporary support in narrow strips.

[0093] Temporary support utilizes an airborne front traverse. This traverse primarily consists of a top traverse frame, connectors, a main frame, a rotating cylinder for the wing traverse, a plug-in two-way lock, high-pressure oil lines, a diverter / collector valve, a relief valve, and a control / operating valve. During operation, oil is supplied by the TBM's crude oil pump. The oil flows through the relief valve to the operating valve, then to the diverter / collector valve, and then into the two-way lock. Once the two-way lock is opened, the oil enters the oil cylinder, sequentially raising the main frame and top frame of the airborne temporary support. The main frame is then raised to the designed tunnel height, and the top traverse frame is connected to the top. Finally, the TBM is locked to initiate support operations.

[0094] The support height of the onboard temporary support device can be customized according to the tunnel specifications. In addition, the onboard front exploration beam can be used in conjunction with the tunnel boring machine to significantly improve the efficiency of rapid excavation.

[0095] Operation steps of the airborne temporary support device:

[0096] ① After the tunnel boring machine completes cutting, the cutting head falls to the ground, the operating valve is opened, and the airborne temporary support top beam is raised above the cutting head.

[0097] ② Place the supporting steel shed or steel net on the top beam frame, attract it with a magnet, and push the supporting main frame and top beam forward.

[0098] ③ Operate the control valve to level the top beam and support the top plate, and shut down the tunnel boring machine.

[0099] ④ Use an anchor drilling rig to complete the installation of anchor rods, and the top and side can be operated at the same time; the anchor rods can be used for temporary support of the top plate before filling.

[0100] In this embodiment, airborne temporary support replaces traditional front-beam temporary support, achieving an initial roof support force of 1.5 tons. This shift from passive to active temporary support facilitates roof control and improves the timeliness of support. The airborne temporary support utilizes a frame-type structure and is supported by a tunnel boring machine, which does not affect normal construction processes. The hydraulic system utilizes the tunnel boring machine's oil pump for oil supply, eliminating the need for additional control equipment. Furthermore, this system effectively reduces worker labor intensity, shortens temporary support time, and improves safety, laying the foundation for rapid coal tunneling.

[0101] The above filling process is as follows:

[0102] 1. Filling preparation

[0103] ① Isolation and sealing of mining strips at the working face

[0104] Due to the unique characteristics of steeply inclined coal seams, mining can create significant risks of coal seam deformation and rock collapse at the working face. Therefore, the isolation walls must be reinforced to prevent collapse of branch tunnels due to excessive filling pressure. Install the isolation walls strictly according to design requirements, ensuring a complete seal between the wall and the roof and floor plates to prevent leakage of filling material.

[0105] ②Pipeline layout and inspection

[0106] Filling route: return air main tunnel 1 → return air stone gate 14 → return air uphill 2 → connecting tunnel → working face.

[0107] Due to the steep inclination of the coal seam, the pipeline layout must be flexible and stable to prevent deformation or blockage caused by external pressure or tilt. Check the inclination angle and fixing conditions of the filling pipeline to ensure it is securely installed. Use elbow connectors at pipe bends to reduce friction. Also, check the pipeline for unobstructed flow in advance and perform leak tests on all key parts, including pipes and valves.

[0108] ③ Equipment and personnel preparation

[0109] The discharge capacity of the filling pump and paste pumping system needs to be optimized according to the inclination of the coal seam, and the pumping pressure and flow rate should be adjusted according to actual conditions to meet the filling needs of steeply inclined coal seams. Underground operators should be familiar with operating procedures and have relevant safety plans in place.

[0110] 2. Pipeline water pumping

[0111] ①Purpose and operation of water pumping

[0112] Due to the steep inclination of the coal seam, gas entrapment and uneven water flow can easily occur within the pipes, leading to blockages or incomplete filling. Ensure that all pipes are filled with water during pumping, especially around bends and high points, and be careful to remove gas. Dedicated personnel are assigned to monitor the filling station and the end of the working face to ensure unimpeded water flow and unobstructed pipes.

[0113] ②Pipeline inspection

[0114] Filling pipes must pass through long, inclined sections. If the water or material flow rate is too fast, it may cause excessive pressure in the pipe, thus affecting the filling effect. Inspect the water flow at the end of the pipe to ensure there is no air entrapment or uneven water flow. If any problems are found, they should be promptly investigated and addressed to ensure that the pipe system is leak-free and free of air accumulation.

[0115] 3. Mortar water pushing

[0116] ①Mortar proportioning and pushing

[0117] Due to the steep inclination of the coal seam, the paste and mortar must have high fluidity requirements, otherwise the paste may block the pipe or cause uneven filling. During the mortar delivery process, use a mortar mix with good fluidity and ensure that the pumping pressure is appropriate for the coal seam inclination. A dedicated person should be assigned to monitor the water flow from the three-way valve at the working surface to ensure smooth mortar delivery under steep inclination conditions.

[0118] ② Mortar filling amount control

[0119] During the mortar pushing process, too much or too little mortar may affect the subsequent filling effect of the paste, so the amount of mortar pushed each time should be controlled within 30m 3 To ensure that the transition between mortar and paste is not affected, adjust the flow rate and filling amount of mortar in time according to the actual situation of the working surface.

[0120] 4. Paste mortar

[0121] ①Paste pumping and control

[0122] Due to the steep inclination of the coal seam, controlling the paste's viscosity and flow rate is crucial. Insufficient paste fluidity can lead to paste stagnation or accumulation, resulting in uneven filling. When the filling station begins pumping the paste, the viscosity and flow rate should be adjusted to ensure they meet the requirements of the steeply inclined conditions. Furthermore, dedicated personnel should be assigned to monitor the paste flow on the working face to prevent stagnation in the highly inclined sections.

[0123] ②Continue to follow up on the filling of mortar and paste

[0124] During the paste pushing process, uneven pipe pressure or flow rate can easily occur, leading to uneven paste filling. Therefore, the mortar should be pushed as needed immediately after the filling process to ensure uniform filling pressure and avoid blockages or bubbles in the pipe. Especially in high-inclination sections, paste filling and mortar pushing in the pipe should be coordinated to prevent blockages.

[0125] 5. Normal filling

[0126] ① Filling material transportation and compaction

[0127] Because paste has poor self-flow properties on slopes, it may settle or accumulate. During the filling process, seamless steel pipes are used to transport the evenly mixed paste to the branch tunnel entrance. A high-pressure hose should be connected to the pipe outlet, and the hose should be raised as obliquely as possible to complete the filling process using the paste's self-flow properties. For branch tunnels with steeper slopes, the hose angle should be adjusted appropriately to enhance paste fluidity and compaction.

[0128] ② Segmented filling

[0129] Filling must be done section by section to ensure effective accumulation and uniform compaction of the filling material. Fill from the bottom of the narrow strip to the top, ensuring uniform paste compaction throughout the filling process. After each narrow strip is filled, a slurry retaining plate is promptly installed to seal it. The top of the narrow strip is the end of the narrow strip at one end of the finger-shaped connecting tunnels 9 and 11, while the bottom refers to the end connected to the return air uphill 2.

[0130] 6. Mortar pushing gangue plaster

[0131] Separating the mortar from the waste rock slurry is crucial because mixing the two can lead to uneven accumulation of the waste rock slurry, impacting the filling effect. When filling is nearing completion, notify the filling station promptly to push the mortar and control the amount of paste added to prevent mixing of the mortar and waste rock slurry, which could lead to pipe blockage or filling failure.

[0132] 7. Water-pushed mortar

[0133] ①Cleaning pipes and valves

[0134] Pipe cleaning is particularly important because slurry or material may accumulate in the pipeline, especially in inclined sections. Use water to clean the pipeline, especially the valve at the end of the main pipeline. Each time you clean the valve, you must open and close it several times to ensure that the valve is completely clean and avoid blockage.

[0135] ② Winding and acceptance

[0136] The blowing operation may be affected by pressure differences, resulting in unstable air flow. When starting the blowing operation, make sure there is no air stagnation in the filling pipe.

[0137] ③ Acceptance after filling work is completed

[0138] After filling is completed, report the filling operation status to the mine dispatch room in a timely manner and prepare to switch to the next filling strip.

[0139] The filling time is delayed and a narrow strip is excavated. The filling sequence is: B4→A4→B3→A3→B2→A2→B1→A1.

[0140] It is obvious to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the present invention can be implemented in other specific forms without departing from the spirit or essential features of the present invention. Therefore, no matter from which aspect, the embodiments should be regarded as exemplary and non-restrictive, and the scope of the present invention is defined by the appended claims rather than the description of the above embodiments, and it is intended that all changes that fall within the meaning and scope of the equivalent elements of the claims are included in the present invention. Any figure mark in the claims should not be regarded as limiting the claim involved. In addition, it is obvious that the word "comprising" does not exclude other units or steps, and the singular does not exclude the plural. Words such as first, second, etc. are used to indicate names and do not indicate any particular order.

Claims

1. A method for upward horizontal segmented continuous mining and filling of a group of steeply inclined and closely spaced coal seams, comprising: The working face system layout is determined based on the distribution of steeply inclined and closely spaced coal seams. The distance between the mining branch tunnel and the filling branch tunnel, i.e., the width of the interval coal pillar, is preliminarily determined based on the overlying rock pressure of the coal seams, the ultimate bearing capacity of the pressure-bearing coal pillar, and the surrounding rock stability requirements. Select working face parameters, including cross-sectional shape and size of branch tunnels, based on coal mine output, coal seam thickness, and mining equipment parameters; Based on the width of the interval coal pillars, the coal seam is divided into a plurality of horizontal strips along the inclination, with every two adjacent strips forming a stage; the strips in each stage are further divided horizontally into a plurality of narrow strips, i.e., each stage includes a plurality of low-level narrow strips and a plurality of high-level narrow strips; A return air tunnel and a transport tunnel are arranged parallel to the coal seam direction in the upper and lower coal seams respectively; a return air uphill tunnel is arranged parallel to the coal seam inclination between the return air tunnel and the transport tunnel; a transport uphill tunnel is arranged at a certain angle to the coal seam inclination at the other end of the transport tunnel; a return air stone gate is arranged at a certain angle to the coal seam inclination at the other end of the return air tunnel; a turning chamber is arranged at the intersection of the transport uphill tunnel and the return air stone gate; In each stage, a low-level finger-shaped connecting tunnel intersecting chamber is arranged in the transport uphill, and starting from the chamber, a low-level finger-shaped connecting tunnel connected to the low-level narrow strip is set; starting from the turning chamber, a transport stone gate is horizontally set, and a high-level finger-shaped connecting tunnel intersecting chamber is set at the end of the transport stone gate; starting from the high-level finger-shaped connecting tunnel intersecting chamber, a high-level finger-shaped connecting tunnel connected to the high-level narrow strip is set; The longwall method is used to arrange mining equipment in the working face, and the continuous mining and filling method is adopted to carry out coal mining in the working face.

2. The mining method according to claim 1, characterized in that: When mining coal on the working face, narrow strips are mined and filled in batches; in each stage, after the first low-level narrow strip is mined, the first high-level narrow strip is mined and the first low-level narrow strip is filled at the same time; then the second low-level narrow strip is mined and the first high-level narrow strip is filled at the same time; and so on, the mining and filling of the entire working face are completed.

3. The method according to claim 1 or 2, characterized in that When determining the width of the interval coal pillars, first determine the width range of the interval coal pillars according to the following formula: Where w is the width of the interval coal pillar, k is the safety factor (generally 1.5 to 2.5), γ is the bulk density of the overlying rock layer, H is the depth of the coal seam, α is the inclination angle of the coal seam, and σ is the relative humidity. c is the uniaxial compressive strength of coal, h is the thickness of the coal seam; Secondly, numerical simulation is used to select the optimal interval coal pillar width according to the stability of the surrounding rock within the preliminarily determined interval coal pillar width range.

4. The method according to claim 1, wherein The excavation branch tunnel adopts a rectangular cross-section; after the cross-section of the excavation branch tunnel is determined, the width of the excavation branch tunnel is determined according to the parameters of the mining equipment and the thickness of the coal seam; the height of the excavation branch tunnel is determined according to the expected production and the width of the excavation branch tunnel; The output calculation formula is: A0=L×S×γ×n÷10000 Where A0 is the annual output; L is the annual excavation length of the tunnel, S is the cross-sectional area of ​​the excavation branch tunnel, γ is the bulk density of coal, and n is the effective construction rate.

5. The method according to claim 1, wherein The horizontal distances between the high-level finger-shaped connecting tunnel intersection chamber and the low-level finger-shaped connecting tunnel intersection chamber and the strip end are equal.

6. The method according to claim 1, characterized in that Before the narrow strip is excavated, local ventilation is adopted. After the narrow strip is excavated and connected to the return air uphill, full wind pressure ventilation is implemented: fresh air flows from the transport tunnel through the transport uphill, low-level or high-level finger-shaped connecting tunnel to the working face; polluted air flows from the working face to the return air uphill, and then through the return air stone gate to the return air tunnel.

7. The method according to claim 1, characterized in that In the working face system, a transportation system is arranged, and the transportation routes are as follows: Coal transportation route: working face → low-level or high-level finger-shaped connecting tunnel → transportation uphill → transportation main tunnel; Auxiliary transport routes to the working face: transport main tunnel → transport uphill → low-level or high-level finger-shaped connecting tunnel → working face; The mining equipment is transported from the low narrow strip to the high narrow strip route: low narrow strip → low finger connecting tunnel → transport up the mountain → high finger connecting tunnel → high narrow strip.

8. The method according to claim 1, characterized in that During narrow strip mining, starting from the intersecting chamber of the low-level finger-shaped connecting tunnel, the low-level finger-shaped connecting tunnel is excavated to the low-level narrow strip mining working face; narrow strip mining and bottom pulling are carried out; at the same time, starting from the intersecting chamber of the high-level finger-shaped connecting tunnel, the high-level finger-shaped connecting tunnel is excavated to the high-level narrow strip mining working face; after the low-level narrow strip is mined, the mining equipment is moved to the corresponding high-level narrow strip for mining; at the same time, the entire space of the mined strip is filled with paste.

9. The method according to claim 1, characterized in that The roof of the goaf is managed by the full filling method, and airborne front exploration beams plus a small number of anchor rods are used as temporary support in narrow strips.

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