Method for coordinated unloading, support, and filling of roadways along the goaf in steeply inclined fully mechanized coal seams

Abstract

This invention discloses a method for coordinated unloading-support-filling roadway protection in a longwall mining face of a steeply inclined coal seam. The method includes: arranging pre-reinforcing anchor bolts and cables at certain intervals in the transport roadway to reinforce the transport roadway in advance; pre-excavating a gap in the upper side of the transport roadway by blasting, and adding reinforcing anchor bolts and cables to the cross-section of the pre-excavated gap; arranging pressure-relief boreholes at certain intervals in the center of the coal seam roof at the pre-excavated gap, and implementing pressure-relief blasting after the support is moved; using I-beams and retractable modular roadway protection supports as the first and second layers of rock-blocking support, respectively; filling and sealing the goaf area above and on the sides of the retractable modular roadway protection supports with local filling materials; and arranging single hydraulic props for delayed support at a certain distance from the coal wall of the lagging face inside the roadway along the goaf. This method provides good support, significantly increases the speed of roadway retention in a longwall mining face of a steeply inclined coal seam, and effectively ensures safe and normal production.

Description

Technical Field

[0001] This invention relates to the field of coal mining technology, specifically to a method for coordinated unloading-supporting-filling roadway protection in a fully mechanized longwall mining face of a steeply inclined coal seam. Background Technology

[0002] my country boasts abundant coal resources with complex and diverse occurrence conditions. Coal seams with a dip angle greater than 35° are collectively referred to as steeply dipping coal seams, widely found in the deep parts of western and eastern mining areas of my country. They account for approximately 20% of proven reserves and 10% of production, and are mostly high-quality coal resources that are scarce and subject to protective mining in my country. During the mining of steeply dipping coal seams, the mechanical behavior of the coal and rock mass is complex and variable, easily inducing large-scale environmental disasters in the inclined mining space. These are internationally recognized as difficult-to-mine coal seams, and their safe and efficient mining is one of the major engineering problems that urgently need to be solved to ensure the stable supply of national energy and the economic and social development of regions.

[0003] Currently, pillarless roadway protection technology has many advantages in alleviating the tension of mining succession, reducing coal resource loss, and improving coal production efficiency, making it an important development direction for green and efficient coal mining technology. However, with the continuous expansion of the application of goaf retention technology, the increasing dip angle, burial depth, thickness, and advance speed of the fully mechanized mining face have brought significant challenges to the surrounding rock structure, stress state, and stability control of the roadway support structure.

[0004] In longwall mining faces of steeply inclined coal seams, the roadways are often asymmetrical and irregularly shaped. During the mining of such coal seams, the stress distribution, failure, and movement characteristics of the surrounding rock in the roadways are highly variable, making support difficult and causing a continuous tension in the mining relationship. Due to the large dip angle of the coal seam, the falling gangue from the roof of the working face will slide, roll, and impact the lower roadways, thereby increasing the asymmetrical deformation of the surrounding rock in the goaf roadways, reducing the stability of the roadway support, and even inducing roof safety accidents in the goaf roadways, which seriously restricts the normal and rapid advancement of longwall mining faces of steeply inclined coal seams. Summary of the Invention

[0005] To address the aforementioned deficiencies in the existing technology, the present invention aims to provide a method for coordinated unloading-supporting-filling roadway protection in a steeply inclined coal seam longwall mining face. This method improves the stability of the roadway support structure, significantly increases the speed of roadway retention in a steeply inclined coal seam longwall mining face, and effectively ensures safe and normal production.

[0006] The present invention is achieved through the following technical solution.

[0007] One aspect of the present invention provides a method for coordinated unloading-supporting-filling roadway protection in a fully mechanized longwall mining face of a steeply inclined coal seam, comprising the following steps:

[0008] Pre-reinforcement anchor bolts and pre-reinforcement anchor cables are installed at certain intervals in the transport roadway, and the roadway along the goaf is reinforced in advance after mining a certain distance in the advanced working face.

[0009] According to the design cross-section of the roadway, a pre-excavated gap is made in the upper side of the transport roadway by blasting, and the cross-section is enlarged; pre-excavation gap reinforcement anchor bolts and pre-excavation gap reinforcement anchor cables are added to the coal side and roof of the pre-excavation gap to reinforce and support the pre-excavation gap.

[0010] A pressure relief blasting borehole was set in the center of the roof of the pre-excavated coal seam;

[0011] Hydraulic supports are installed at the working face, and steel beams for retaining coal seam are arranged at the bottom of the transport roadway to form the first layer of retaining coal seam support in the goaf. After the working face is moved, roof pressure relief blasting is carried out to fully fracture the roof strata in the goaf and effectively improve the stress distribution characteristics of the surrounding rock in the roadway along the goaf.

[0012] A retractable modular roadway support is arranged on the side of the pre-excavated gap in the transport roadway. The top and sides of the retractable modular roadway support are filled and sealed with local filling material, and the outer surface is sealed with grout to form the second layer of rock retaining support in the goaf.

[0013] After the working face is mined, the transport roadway is located at the edge of the goaf area of ​​the working face. After the surrounding rock of the roadway formed along the goaf enters the slow subsidence and deformation zone, the individual hydraulic supports are gradually withdrawn and moved, and observation points are set on the roof of the withdrawn individual pillar area; the lagging coal wall is reinforced with individual hydraulic props at a certain distance.

[0014] As a preferred option, advanced reinforcement anchor bolts and advanced reinforcement anchor cables are arranged on the lower side wall of the roadway floor and the roadway roof at intervals of 1.0 to 1.5m.

[0015] As a preferred option, a gap is pre-excavated by blasting on the upper side of the transport roadway, with a gap width of 1m to 1.5m and a height equal to the coal seam thickness.

[0016] Preferably, the spacing and row spacing of the pre-excavation gap reinforcement anchor bolts and pre-excavation gap reinforcement anchor cables are 1.0m×1.0m; metal mesh and steel reinforcement beams are used to reinforce and support the pre-excavation gap.

[0017] As a preferred option, blasting positions and blasting point spacing are set at a certain angle towards the working face in the center of the roof of the pre-excavated gap coal seam along the strike direction, and blasting roof cutting and pressure relief boreholes are arranged, with the borehole depth reaching above the basic roof of the coal seam.

[0018] As a preferred option, retaining steel beams are arranged along the strike of the coal seam floor using top anchors and ground anchors at the upper side of the transport roadway. The retaining steel beams are fixed to the top and bottom of the coal seam, and a flexible pad layer is set above the retaining steel beams.

[0019] As a preferred option, a flexible pad layer is set above the retaining steel beam, which is made of semi-circular wood, metal mesh and waste rubber, and tied and fixed with iron wire to achieve the first layer of retaining buffer.

[0020] As a preferred option, the local filling material consists of a cement backing plate and woven bags filled with coal gangue.

[0021] As a preferred approach, the single hydraulic props are completely withdrawn in the stable zone, while anchor cables are added and temporary single props are erected in the unstable zone for active reinforcement and stabilization.

[0022] The present invention, by adopting the above technical solution, has the following beneficial effects:

[0023] 1) By pre-excavating gaps in the upper side of the transport roadway, adding parallel anchor bolts, and reinforcing the support with anchor cables, the deformation of the upper side of the transport roadway is effectively controlled, avoiding the problem of spalling above the pre-excavated gaps; the operating space for the pre-decompression process of the coal seam roof is greatly increased, and the depth of the blasting roof cutting and decompression drilling along the strike direction can reach above the basic roof of the coal seam. By blasting or dense drilling, the roof strata of the goaf are fully fractured, effectively improving the stress distribution characteristics of the surrounding rock in the goaf-retaining roadway; at the same time, it also provides a large operating space for installing the first layer of rock retaining support.

[0024] 2) By arranging retaining steel beams and flexible cushion layers along the strike above the triangular base of the coal seam floor in the transport roadway, the first retaining wall in the goaf was achieved; the second retaining wall in the goaf was completed by using retractable modular roadway support; construction can be carried out by other work groups without occupying the working face mining time, and has significant advantages such as relatively small workload, high safety factor and short time, which improves the speed and safety of roadway retention along the goaf in steeply inclined coal seam longwall mining faces.

[0025] 3) By arranging cement back plates and filling woven bags filled with coal gangue under the first coal gangue retaining steel beam and above the second coal gangue retaining support, local filling and sealing can be carried out to reduce air leakage in the goaf, effectively buffer the impact of falling coal gangue on the working face roof, and avoid safety accidents of the roof of the roadway along the goaf. Attached Figure Description

[0026] The accompanying drawings, which are included to provide a further understanding of the invention and form part of this application, do not constitute an undue limitation of the invention. In the drawings:

[0027] Figure 1 This is a system layout plan of the present invention;

[0028] Figure 2 This is a cross-sectional view of the system layout of the present invention;

[0029] Figure 3 This is a flowchart of the method described in this invention;

[0030] Figure 4 This invention relates to the cross-section and support scheme of the transport roadway;

[0031] Figure 5 This is a schematic diagram of the support parameters in step 1 of an embodiment of the present invention;

[0032] Figure 6 This is a schematic diagram of the support parameters in step 2 of an embodiment of the present invention;

[0033] Figure 7 This is a schematic diagram of the support parameters in step 3 of an embodiment of the present invention;

[0034] Figure 8 This is a schematic diagram of the support parameters in step 4 of an embodiment of the present invention;

[0035] Figure 9 This is a schematic diagram of the support parameters in step 5 of an embodiment of the present invention;

[0036] Figure 10 This is a schematic diagram of the support parameters in step 6 of an embodiment of the present invention.

[0037] In the diagram: 1-Transport roadway; 2-Roadway anchor bolt; 3-Roadway anchor cable; 4-Pre-excavation gap reinforcement anchor bolt; 5-Pre-excavation gap reinforcement anchor cable; 6-Pressure relief borehole; 7-Hydraulic support; 8-Steel retaining beam; 9-Goaf; 10-Flexible cushion layer; 11-Retractable modular roadway protection support; 12-Partial filling body; 13-Single hydraulic prop; 14-Metal mesh and steel reinforcement support beam; 15-Advanced reinforcement anchor bolt; 16-Advanced reinforcement anchor cable; 17-End support; 18-Top anchor; 19-Ground anchor; 20-Steel beam column socket. Detailed Implementation

[0038] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. The illustrative embodiments and descriptions of the present invention are used to explain the present invention, but are not intended to limit the present invention.

[0039] like Figures 1-3 As shown, the present invention provides a method for coordinated unloading-supporting-filling of roadways along the goaf in a steeply inclined coal seam longwall mining face, comprising the following steps:

[0040] Step 1: Advanced reinforcement of the transport tunnel.

[0041] According to the layout method of fully mechanized roadways in steeply inclined coal seams, the working face transport roadway is retained as the target roadway during the mining process and used as the return airway for the next section of mining. The transport roadway is generally supported by roadway anchor bolts 2 and roadway anchor cables 3, and end supports 17 are arranged at the connection between the working face and the transport roadway. First, advance reinforcement anchor bolts 15 and advance reinforcement anchor cables 16 are arranged at a certain interval on the lower sidewall of the floor and the roof of the transport roadway 1. The roadway is reinforced after mining a certain distance ahead of the working face, so as to improve the bearing capacity of the roadway and prevent the floor of the transport roadway from slipping and the roof from collapsing.

[0042] Step 2: Pre-excavate a gap in the sidewall of the transport roadway.

[0043] According to the cross-sectional design of the goaf-retaining roadway, a gap is made in the upper side of the transport roadway 1. Based on the height and width of the transport roadway, a reasonable pre-excavation gap position is designed. The gap is pre-excavated by blasting in the upper side of the transport roadway. Preferably, the gap width is 1m to 1.5m, and the height is the coal seam thickness.

[0044] First, a gap is created using precise controlled blasting. Then, the cross-section is widened by manual trimming until the cross-section required for the goaf roadway is formed, providing sufficient space for the next step of the operation. At the same time, the pre-excavated gap is reinforced and supported by adding pre-excavated gap reinforcing anchor bolts 4 and pre-excavated gap reinforcing anchor cables 5 at the coal face and roof of the pre-excavated gap cross-section, as well as by using metal mesh and steel reinforcement beams 14, to increase the stability and bearing capacity of the roadway. The pre-excavated gap and the reinforcing support are carried out in parallel to prevent the top of the pre-excavated gap from collapsing. The spacing and row spacing of the pre-excavated gap reinforcing anchor bolts 4 and pre-excavated gap reinforcing anchor cables 5 are determined according to the cross-section and roof conditions. During this period, the pre-excavated gap and the reinforcing support are carried out in parallel.

[0045] Step 3: Drill holes for cutting and decompression in advance on the top plate.

[0046] Along the strike direction, at a certain angle, in the center of the pre-excavated gap coal seam roof, a reasonable blasting position and blasting point spacing are designed to ensure that the collapsed roof after blasting will not crush the retaining rock facilities. Blasting roof cutting and pressure relief borehole 6 is arranged, with the borehole depth reaching above the basic roof of the coal seam. After the first retaining rock facility in the goaf 9 is completed and the working face is moved, the blasting operation is carried out.

[0047] Step 4: Arrangement of the first retaining wall support in the goaf.

[0048] Under the protection of the hydraulic support 7 at the working face, retaining steel beams 8 are first arranged along the strike of the coal seam floor in the transport roadway. Top anchors 18 and ground anchors 19 are used to fix the retaining steel beams 8 to the coal seam roof and floor. The upper end of the steel beam is anchored to the roof with threaded steel anchor rods, and the lower end is fixed by excavating steel beam post sockets 20. To further increase the stability of the roof and floor, a flexible cushion layer 10 is installed above the retaining steel beams 8. The flexible cushion layer is made of semi-circular wood, metal mesh, and waste rubber, bound and fixed with wire, thus realizing the first retaining support device for the collapsed gangue in the upper section goaf 9.

[0049] Step 5: Support with retractable modular tunnel protection supports.

[0050] A semi-circular arched retractable modular roadway support 11 is arranged on the side of the pre-excavated gap in the transport roadway. The top and sides of the retractable modular roadway support 11 are filled and sealed with a partial filling body 12. The partial filling body 12 is generally composed of a cement backing plate and woven bags filled with coal gangue. At the same time, the outside is sealed with grout to reduce the space between the retractable modular roadway support and the roadway sidewall, so that the retractable modular roadway support 11 is completely attached to the roadway, preventing air leakage in the goaf, and effectively buffering the impact of the falling gangue from the roof of the working face, serving as the second layer of gangue retaining support in the goaf.

[0051] Step 6: Delayed reinforcement support.

[0052] After the working face is mined, the transport roadway is located at the edge of the goaf area. The goaf retention roadway is successfully completed and can be used as a return airway for the next section. Once the surrounding rock of the goaf retention roadway enters a slow subsidence and deformation zone, the individual hydraulic props are gradually withdrawn and moved, and observation points are set up on the roof of the withdrawal zone. To prevent roof collapse in the goaf retention roadway, individual hydraulic props 13 are used for delayed reinforcement support of the lagging coal wall at certain intervals. The individual hydraulic props 13 are arranged along the goaf retention roadway direction, with the row spacing determined according to the roadway size. Preferably, two rows of individual hydraulic props are arranged along the direction.

[0053] Based on the deformation, delamination, integrity, and damage of the roof of the goaf-side roadway, a comprehensive assessment of the stability of the roof of the goaf-side roadway is conducted. In the stable zone, the single hydraulic prop 13 is completely withdrawn, and in the unstable zone, active reinforcement and stabilization support is carried out by adding anchor cables and erecting temporary single props.

[0054] The present invention will be further illustrated below through specific embodiments.

[0055] The No. 18 coal seam in a certain coal mine has a burial depth of 315.3m to 548.2m, which is a relatively stable coal seam. The total thickness of the coal seam is 1.39m to 3.87m, with an average thickness of 2.25m. The maximum dip angle of the coal seam is 48°, the minimum dip angle is 35°, and the average dip angle is 42°. The coal seam is soft with well-developed fissures and joints, and the coal seam hardness is relatively soft (f<2), which is not conducive to roof management during the mining of the working face. The roof of the coal seam is mainly composed of siltstone and coarse sandstone, with the old roof being coarse sandstone with a thickness of 24.15m and an f coefficient of 7-8, which is a thick and hard rock layer. The working face has a strike length of 1042m, an dip length of 128m, and a mining height of 2.5m. It is a steeply dipping medium-thick coal seam being mined. During the mining process, the deformation of the roadway along the goaf is large, and the support is difficult.

[0056] Original roadway support scheme: The 1056m long transport roadway of working face 31182 is excavated along the roof and floor of coal seam #18. The roadway has an arched cross-section, with a bottom width of 4.0m, a middle height of 2.6m, a cross-sectional area of ​​9.38㎡, and a net cross-sectional area of ​​9.29㎡. The following scheme was adopted: Anchor bolts The support system uses a combination of anchor cables and reinforced beams, with eight rows of anchor bolts arranged at a spacing of 1.0m x 1.0m. Anchor cables are placed every 3.0m along the direction, in three rows. Figure 4 As shown.

[0057] Step 1: Advanced reinforcement of transport tunnels, such as... Figure 5 As shown. 30m before the working face is mined, a row of... Advanced reinforcement anchor cable 16 and a row 15 pre-reinforcement anchor bolts were installed, with an anchor cable spacing of 1.0m. The pre-reinforcement anchor bolts and anchor cable rows were spaced 1.0m apart, and the anchor bolt spacing was 1.0m, for anchoring. Two more rows were then installed at the coal seam roof. Sixteen pre-installed reinforcing anchor cables, spaced 1.0m apart, are used to prevent rock slippage from the coal seam floor to the roadway floor in the transport roadway.

[0058] Step 2: Excavate a gap in the upper side of the transport roadway and widen the cross-section, such as... Figure 6 As shown. Based on the designed gob-side roadway section, the working face is advanced 5m to 8m ahead of the coal face. Rough blasting and manual trimming are used to achieve the designed gob-side roadway section and pre-excavation gap working space. The gap is 2.3m wide and 2.5m high. The pre-excavation gap is carried out parallel to the reinforcement support. Two rows are added to the coal face at the gap section. Four reinforcing anchor bolts are installed along the sidewalls, with the upper and lower rows of anchor bolts 0.5m away from the top and bottom slabs. Two rows of anchor bolts are installed along the direction of the gap in the top slab. Five reinforcing anchor cables are used, with a distance of 1.0m between the anchor cables and the cross-section, and a row spacing of 1.0m between the anchor cables.

[0059] Step 3: Drill 6 pre-cutting and pressure-relieving boreholes in the roof of the transport tunnel, such as... Figure 7 As shown. Along the strike direction, at a 45° angle with the dip of the coal seam, six roof pressure relief boreholes are arranged in the center of the pre-excavated gap in the roof. The boreholes are 8m deep, spaced 0.6m apart, with a drill bit diameter of 36mm, and vertically directed towards the roadway. The boreholes are sealed to a depth of 2.0m and loaded with 6m of explosives. The explosives are loaded before the support is moved after the first I-beam rock-blocking device is completed. Blasting is carried out after the support is moved.

[0060] Step 4: First-stage rock-blocking support, such as... Figure 8 As shown. Under the protection of hydraulic support 7 at the No. 1 working face, I-beams 8 are first arranged along the strike at a distance of no less than 1000mm above the coal seam floor in the transport roadway. The I-beams 8 are made of No. 11 I-beams, spaced 0.5m apart. The upper and lower ends of the I-beams 8 are fixed to the coal seam roof and floor using top anchors 18 and ground anchors 19, respectively, to further increase the stability of the roof and floor. The top anchors 18 and ground anchors 19 are made of... and The threaded steel anchor rod has a column socket 20 with a depth of at least 0.2m at the bottom. The upper part of the I-beam 8 is made of semi-circular wood, metal mesh and waste rubber, which are tied and fixed with iron wire to serve as a flexible cushion layer 10 to realize the first blockage support for the collapsed gangue in the upper section goaf 9.

[0061] Step 5: Support with retractable modular tunnel protection supports, such as... Figure 9 As shown, semi-circular arched retractable modular roadway protection supports 11 are arranged along the strike on the side of the pre-excavated gap in the transport roadway, with a spacing of 0.8m. The top and sides of the retractable modular roadway protection supports 11 are filled and sealed with filling bodies 12, which are generally composed of cement backing plates and woven bags filled with coal gangue. At the same time, the outside is sealed with grout to reduce the space between the retractable modular roadway protection supports and the roadway sidewall, so that the retractable modular roadway protection supports 11 are completely attached to the roadway to prevent air leakage in the goaf.

[0062] Step 6: Delayed reinforcement support, such as Figure 10 As shown, after the working face is mined, the transport roadway is located at the edge of the goaf area. The goaf retention roadway is successfully completed and can be used as a return airway for the next section. To prevent roof collapse in the goaf retention roadway, single hydraulic props (13) are used for delayed reinforcement at a certain distance from the coal face. Two rows of single hydraulic props (13) are arranged along the strike, in the middle of the roadway and on the right side, with a spacing of 1.5m. When the length of the goaf retention roadway reaches 5m, they need to be moved back. Based on the roof deformation, delamination, roof integrity, and damage conditions in the goaf retention roadway, a comprehensive assessment and zoning of the roof stability is conducted. Single hydraulic props (13) are withdrawn beyond a 50m delay in the goaf retention roadway. Active reinforcement and stabilization support are implemented in unstable areas, such as installing anchor cables and erecting temporary single hydraulic props.

[0063] This invention solves the problems of increased asymmetric deformation of the surrounding rock and reduced stability of the roadway support in longwall mining faces with steeply inclined coal seams during coal seam mining. These problems include difficulties in supporting the surrounding rock of the roadway and the impact of falling gangue from the roof of the working face into the lower roadway. This effectively avoids roof safety accidents in roadways with the roadway support and significantly improves the advance speed of longwall mining faces in steeply inclined coal seams.

[0064] This invention is not limited to the above embodiments. Based on the technical solutions disclosed in this invention, those skilled in the art can make some substitutions and modifications to some of the technical features without creative effort, and all such substitutions and modifications are within the protection scope of this invention.

Claims

1. A method for simultaneous support and filling of a gob-side entry at a fully mechanized coal face in a steeply inclined coal seam, characterized in that, Includes the following steps: Pre-reinforcement anchor bolts and pre-reinforcement anchor cables are installed at certain intervals in the transport roadway, and the roadway along the goaf is reinforced in advance after a certain distance is mined in the advance working face. Pre-reinforcement anchor bolts and pre-reinforcement anchor cables are arranged at intervals of 1.0~1.5m on the lower side wall of the roadway floor and the roadway roof. According to the design cross-section of the roadway, a pre-excavated gap is blasted in the upper side of the transport roadway, and the cross-section is enlarged; pre-excavation gap reinforcement anchor bolts and pre-excavation gap reinforcement anchor cables are added to the coal side and roof of the pre-excavation gap, and metal mesh and steel beams are used to reinforce and support the pre-excavation gap. Decompression blasting boreholes with a certain spacing are arranged in the center of the roof of the pre-excavated gap coal seam; Hydraulic supports are installed at the working face, and retaining steel beams are arranged at the bottom of the coal seam on the upper side of the transport roadway. Retaining steel beams are also arranged along the strike of the coal seam on the upper side of the transport roadway using top anchors and ground anchors. The retaining steel beams are fixed to the top and bottom of the coal seam, and a flexible cushion layer is set on top of the retaining steel beams. The flexible cushion layer is made of semi-circular wood + metal mesh + waste rubber and is bound and fixed with iron wire to form the first retaining support of the goaf. After the working face is moved, the roof pressure relief blasting operation is carried out; a retractable modular roadway support is arranged on the side of the pre-excavated gap in the transport roadway. The top and sides of the retractable modular roadway support are filled and sealed with a partial filling body composed of cement backing plates and woven bags filled with coal gangue. The outer surface is sealed with grout to form the second gangue retaining support in the goaf. After the working face is mined, the transport roadway is located at the edge of the goaf area of ​​the working face. After the surrounding rock of the roadway formed along the goaf enters the slow subsidence and deformation zone, the single hydraulic supports are gradually withdrawn and moved, and observation points are set on the roof of the single pillar withdrawal zone; the lagging coal wall is reinforced with single hydraulic props at a certain distance.

2. The method according to claim 1, characterized in that, In the transport roadway, a blasting pre-excavation gap is made on the upper side, with a gap width of 1m to 1.5m and a height equal to the coal seam thickness.

3. The method according to claim 1, characterized in that, The spacing and row spacing of the pre-excavation gap reinforcement anchor bolts and pre-excavation gap reinforcement anchor cables are 1.0m×1.0m.

4. The steeply inclined coal seam fully mechanized mining face gob-side entry way unloading-supporting-filling coordinated roadway protection method according to claim 1, characterized in that, Along the strike direction, blasting positions and blasting point spacing are set at a certain angle towards the working face in the center of the pre-excavated gap coal seam roof. Blasting roof cutting and pressure relief boreholes are arranged, and the borehole depth reaches above the basic top of the coal seam.

5. The steeply inclined coal seam fully mechanized mining face gob-side entry way unloading-supporting-filling coordinated roadway protection method according to claim 1, characterized in that, In the stable zone, the single hydraulic props are completely withdrawn, and in the unstable zone, anchor cables are added and temporary single props are erected for active reinforcement and stabilization.

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