Unloading-supporting-filling cooperative roadway protection method for gob-side roadway of fully mechanized coal mining face of steeply inclined coal seam

Abstract

The invention discloses a steeply inclined coal seam fully mechanized coal mining face gob-side roadway unloading-supporting-filling cooperative roadway protection method which comprises the following steps: arranging advanced reinforcing anchor rods and advanced reinforcing anchor cables at a certain interval in a transportation roadway, and carrying out advanced reinforcement on the transportation roadway on an advanced working face; blasting a pre-excavated notch on the upper side part of the transportation roadway, and adding a reinforcing anchor rod and an anchor cable on the cross section of the pre-excavated notch; pressure relief drill holes are formed in the center of a top plate of the pre-excavated gap coal seam at certain intervals, and pressure relief blasting is carried out after the support is moved; i-shaped steel beams and retractable module roadway protection supports are adopted as a first waste rock blocking support and a second waste rock blocking support respectively; a local filling body is adopted on the upper portion and the side face of the retractable module entry protection support to fill and block a gob, and a single hydraulic prop lagging support is arranged in a gob-side entry retaining roadway by a certain distance behind the coal wall of a working face. The method is good in supporting effect, the gob-side entry retaining speed of the strike long-wall fully mechanized coal mining face of the steeply inclined coal seam is greatly increased, and safe and normal production is effectively guaranteed.

Description

Technical Field

[0001] The invention relates to the technical field of coal mining, and in particular to a method for coordinated tunnel protection of an unloading-supporting-filling tunnel along a gob in a fully-mechanized mining working face of a steeply inclined coal seam. Background Art

[0002] my country is rich in coal resources, and the occurrence conditions are complex and diverse. Coal seams with an inclination angle greater than 35° are collectively referred to as high-angle and steeply inclined coal seams. They are widely distributed in the deep parts of my country's western and eastern mining areas, accounting for about 20% of the proven reserves and 10% of the output. Most of them are high-quality coal (types) that are in short supply and protected for mining in my country. During the mining process of high-angle and steeply inclined coal seams, the mechanical behavior of the coal and rock mass is complex and changeable, which can easily induce large-scale inclined coal mining space environmental disasters. They are internationally recognized as difficult-to-mine coal seams. Their safe and efficient mining is one of the major engineering issues that need to be solved urgently to ensure the stable supply of national energy and regional economic and social development.

[0003] At present, the technology of non-coal pillar roadway protection has many advantages in alleviating the tension of mining and excavation, reducing the loss of coal resources, and improving coal production efficiency, and has become an important development direction of green and efficient coal mining technology. With the continuous expansion of the application scope of gob-side roadway retention technology, the increase in coal seam inclination, burial depth, thickness, and the advancement speed of the fully mechanized mining face has brought great difficulties to the control of the surrounding rock structure, stress state, and stability of the roadway support body.

[0004] The mining tunnels of longwall fully mechanized mining faces in large-angle and steeply inclined coal seams are mostly asymmetric and irregular in cross-section. During the mining of such coal seams, the stress distribution, damage and movement characteristics of the surrounding rock of the mining tunnels are changeable, and support is difficult, resulting in continuous tension in the mining relationship. Due to the large inclination of the coal seam, the gangue falling from the roof of the working face will slide, roll and impact the lower tunnels, thereby increasing the asymmetric deformation of the surrounding rock of the tunnels retained along the goaf, reducing the stability of the tunnel support body, and even inducing safety accidents in the roof of the tunnels retained along the goaf, seriously restricting the normal and rapid advancement of the longwall fully mechanized mining faces in steeply inclined coal seams. Summary of the invention

[0005] In order to solve the above-mentioned defects existing in the prior art, the purpose of the present invention is to provide a method for coordinated unloading-supporting-filling of tunnels along the goaf of a comprehensive mining face in a steeply inclined coal seam, which improves the stability of the tunnel support body, greatly increases the speed of retaining tunnels along the goaf of a longwall comprehensive mining face in a steeply inclined coal seam, and effectively ensures safe and normal production.

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

[0007] One aspect of the present invention provides a method for protecting a gob-side tunnel by unloading, supporting and filling in a fully-mechanized mining face of a steeply inclined coal seam, comprising the following steps:

[0008] Arrange advance reinforcement anchor rods and advance reinforcement anchor cables at a certain interval in the transport lane, and conduct advance reinforcement of the lane along the goaf after mining a certain distance at the advance working face;

[0009] According to the design section of the reserved lane, blast the pre-dig gap in the upper part of the transport lane to expand the section; add pre-dig gap reinforcement anchor rods and pre-dig gap reinforcement anchor cables at the coal wall and roof of the pre-dig gap section to reinforce and support the pre-dig gap;

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

[0011] The hydraulic support is set up on the working face, and the steel beams for rock blocking are arranged at the bottom of the upper coal seam in the transport lane to form the first rock blocking support in the goaf. After the working face is moved, the roof pressure relief blasting operation is carried out to fully fracture the rock layer on the roof of the goaf, effectively improving the stress distribution characteristics of the surrounding rock in the goaf-retained lane.

[0012] A retractable module tunnel protection support is arranged on the side of the pre-excavated gap of the transport tunnel. The top and side of the retractable module tunnel protection support are filled and blocked with local filling bodies, and the outer surface is sprayed and sealed to form the second barrier support of the goaf;

[0013] After the working face is mined, the transport tunnel is located at the edge of the goaf area of ​​the working face. After the surrounding rock of the goaf-retained tunnel formed along the goaf enters the slow sinking and deformation zone, the single hydraulic support is gradually withdrawn and migrated, and a single column withdrawal area roof observation point is set; the lagging coal wall is supported by single hydraulic pillars at a certain distance.

[0014] Preferably, advance reinforcement anchor rods and advance reinforcement anchor cables are arranged at intervals of 1.0 to 1.5 m on the lower side of the transport lane floor and the lane roof.

[0015] As a preferred method, a gap is pre-dug by blasting on the upper side of the transport tunnel. The width of the gap is 1m to 1.5m and the height is equal to the thickness of the coal seam.

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

[0017] Preferably, the blasting position and blasting point spacing are set at a certain angle inclined toward the working face in the center of the pre-excavated notch coal seam roof along the strike direction, and blasting top cutting and pressure relief drilling holes are arranged, with the drilling depth reaching above the basic top of the coal seam.

[0018] Preferably, rock-retaining steel beams are arranged along the strike direction at the bottom plate of the upper coal seam in the transport tunnel using top anchors and ground anchors, the rock-retaining steel beams are fixed to the top plate and bottom plate of the coal seam, and a flexible cushion layer is provided above the rock-retaining steel beams.

[0019] Preferably, a flexible cushion layer is provided above the rock-retaining steel beam, and half-round wood + metal mesh + waste rubber are used and tied and fixed with wire to realize the first rock-retaining buffer.

[0020] Preferably, the local filling body is composed of a cement backboard and a woven bag filled with coal gangue.

[0021] As a preferred option, the single hydraulic props are completely withdrawn from the stable area, and additional anchor cables are installed in the unstable area, and temporary single props are set up for active reinforcement and stabilization support.

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

[0023] 1) By pre-digging a gap in the upper part of the transport tunnel, adding anchor rods and anchor cables in parallel to strengthen the support, the deformation of the upper wall of the transport tunnel is effectively controlled, avoiding the problem of wall spalling above the pre-digging gap; the operating space of the coal seam roof advance pressure relief process is greatly increased, and the depth of the blasting and top cutting pressure relief drilling holes arranged along the strike direction can reach above the basic top of the coal seam. The rock strata on the roof of the goaf are fully fractured by blasting or dense drilling, effectively improving the stress distribution characteristics of the surrounding rock of the goaf-retained tunnel; at the same time, it also provides a larger operating space for the installation of the first barrier support.

[0024] 2) By arranging rock-blocking steel beams and flexible cushion layers along the direction above the triangular bottom of the coal seam floor in the transport tunnel, the first rock-blocking in the goaf is realized; the retractable modular tunnel protection bracket is used to complete the second rock-blocking in the goaf; construction can be carried out by other teams without occupying the working face mining time, with the significant characteristics of relatively small engineering volume, high safety factor and short time, which improves the speed and safety of tunnel retention along the goaf of the longwall comprehensive mining working face in the steeply inclined coal seam.

[0025] 3) By arranging cement back plates under the first steel beam and above the second support for local filling and sealing with woven bags filled with coal gangue, air leakage in the goaf can be reduced, the impact of falling gangue on the roof of the working face can be effectively buffered, and safety accidents on the roof of the tunnels along the goaf can be avoided. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The drawings described herein are used to provide a further understanding of the present invention, constitute a part of the present application, and do not constitute an improper limitation of the present invention. In the drawings:

[0027] Figure 1 A plan view of the layout of the system of the present invention;

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

[0029] Figure 3 is a flow chart of the method of the present invention;

[0030] Figure 4 The transport tunnel section and support scheme of the present invention;

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

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

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

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

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

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

[0037] In the figure: 1-transport tunnel; 2-tunnel anchor rod; 3-tunnel anchor cable; 4-pre-excavation gap reinforcement anchor rod; 5-pre-excavation gap reinforcement anchor cable; 6-pressure relief borehole; 7-hydraulic support; 8-gangue retaining steel beam; 9-goaf; 10-flexible cushion layer; 11-retractable modular tunnel protection support; 12-local filling body; 13-single hydraulic support; 14-metal mesh and steel support beam; 15-advance reinforcement anchor rod; 16-advance reinforcement anchor cable; 17-end support; 18-top anchor; 19-ground anchor; 20-steel beam column socket. DETAILED DESCRIPTION

[0038] The present invention will be described in detail below in conjunction with the accompanying drawings and specific embodiments. The exemplary 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 Figure 1-Figure 3 As shown, the method for unloading-supporting-filling coordinated roadway protection in a steeply inclined coal seam fully mechanized mining working face of the present invention comprises the following steps:

[0040] Step 1: Advance reinforcement of transport lanes.

[0041] According to the method of arranging the fully mechanized mining tunnels in steeply inclined coal seams, the working face transport tunnel is retained as the target tunnel during the mining process and used as the return air tunnel for the mining of the lower section. The transport tunnel is generally supported by tunnel anchor rods 2 and tunnel anchor cables 3, and the end bracket 17 is arranged at the connection between the working face and the transport tunnel. First, advance reinforcement anchor rods 15 and advance reinforcement anchor cables 16 are arranged at a certain interval on the lower side of the tunnel floor and the tunnel roof of the transport tunnel 1. The tunnel is reinforced at a certain distance after the advanced working face mining, so that the bearing capacity of the tunnel is improved to avoid the slippage of the transport tunnel floor and the collapse of the roof.

[0042] Step 2: Pre-dig a gap in the side of the transport tunnel.

[0043] According to the cross-sectional design of the gob-side tunnel, a gap is opened in the upper part of the transport tunnel 1. According to the height and width of the transport tunnel, a reasonable pre-excavation gap position is designed, and a pre-excavation gap is blasted in the upper part of the transport tunnel. Preferably, the gap width is 1m to 1.5m, and the height is the thickness of the coal seam.

[0044] First, a gap is opened by precision-controlled blasting, and then the section is expanded by manual trimming until the section required for retaining a tunnel along the goaf is formed, providing sufficient space for the next operation; at the same time, by adding pre-dig gap reinforcement anchor rods 4 and pre-dig gap reinforcement anchor cables 5 at the coal wall and roof of the pre-dig gap section and using metal mesh and steel support beams 14, the pre-dig gap is reinforced and supported to increase the stability and bearing capacity of the tunnel. The pre-dig gap and reinforcement support operate in parallel to prevent the wall from spalling above the pre-dig gap; the spacing and row spacing of the pre-dig gap reinforcement anchor rods 4 and pre-dig gap reinforcement anchor cables 5 depend on the conditions of the section and the roof. During this period, the pre-dig gap and reinforcement support operate in parallel.

[0045] Step 3: Drill holes in the roof to relieve pressure.

[0046] In the center of the pre-excavated notch coal seam roof, along the strike direction, it is inclined to the working face at a certain angle, and reasonable blasting positions and blasting point spacings are designed to ensure that the collapsed roof after blasting will not crush the rock retaining facilities. Blasting and top cutting and pressure relief drilling holes 6 are arranged, and the drilling depth reaches above the basic top of the coal seam. After the construction of the first rock retaining facility in the goaf 9 is completed, blasting operations are carried out after the working face is moved.

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

[0048] Under the protection of the hydraulic support 7 of the working face, the steel beam 8 for blocking the gangue is first arranged along the direction at the bottom plate of the upper coal seam of the transport lane, and the top anchor 18 and the ground anchor 19 are arranged to fix the steel beam 8 to the top plate and the bottom plate of the coal seam. The upper end of the steel beam is anchored to the top plate by a threaded steel anchor rod, and the lower end is fixed by digging a steel beam column socket 20. To further increase the stability of the top plate and the bottom plate, a flexible cushion layer 10 is arranged above the steel beam 8 for blocking the gangue. The flexible cushion layer is made of half-round wood + metal mesh + waste rubber and is tied and fixed with iron wire to realize the first gangue blocking support device for the gangue collapsed in the goaf area 9 of the upper section.

[0049] Step 5: Retractable modular tunnel protection bracket support.

[0050] A semicircular arched retractable modular tunnel protection support 11 is arranged on the side of the pre-excavated gap in the transport tunnel. The top and sides of the retractable modular tunnel protection support 11 are filled and sealed with a local filling body 12. The local filling body 12 is generally composed of a cement backboard and a woven bag filled with coal gangue. At the same time, the outside is sprayed and sealed to reduce the space between the retractable modular tunnel protection support and the side of the tunnel, so that the retractable modular tunnel protection support 11 is completely fitted with the tunnel to prevent air leakage in the goaf, and to achieve effective buffering of the impact of gangue falling from the roof of the working face, serving as the second gangue support in the goaf.

[0051] Step 6: Delayed reinforcement support.

[0052] After the working face is mined, the transport tunnel is located at the edge of the goaf area of ​​the working face, and the goaf-retained tunnel is successful, which can be used as the return air tunnel of the lower section. After the surrounding rock of the goaf-retained tunnel enters the slow sinking deformation zone, the single hydraulic props are gradually withdrawn and migrated, and the roof observation points of the single column withdrawal area are set; to prevent the roof of the goaf-retained tunnel from collapsing, the lagging coal wall is supported by single hydraulic props 13 at a certain distance; the single hydraulic props 13 are arranged along the goaf-retained tunnel, and the row spacing is determined according to the size of the tunnel. Preferably, two rows of single hydraulic props are arranged along the direction.

[0053] According to the deformation, delamination, integrity and damage of the roof of the gob-retained tunnel, a comprehensive assessment of the stability of the roof of the gob-retained tunnel is conducted. The single hydraulic support 13 is completely withdrawn from the stable area, and active reinforcement and stabilization support is carried out in the unstable area by adding anchor cables and setting up temporary single supports.

[0054] The present invention is further illustrated by means of specific examples below.

[0055] The No. 18 coal seam in a coal mine is buried at a depth of 315.3m to 548.2m, which is a relatively stable coal seam with a total thickness of 1.39 to 3.87m and an average thickness of 2.25m. The maximum inclination of the coal seam is 48°, the minimum inclination is 35°, and the average inclination is 42°. The coal seam is soft and has developed cracks, relatively developed joints, and relatively soft hardness (f<2), which is not conducive to roof management during the mining of the working face. The roof of the coal seam is mainly siltstone and coarse sandstone, and the old roof is coarse sandstone with a thickness of 24.15m and an f coefficient of 7-8, which is a thick and hard rock formation. The working face has a strike length of 1042m, an inclination length of 128m, and a mining height of 2.5m. It belongs to the mining of steeply inclined medium-thick coal seams. During the mining process, the deformation of the tunnels left along the goaf is large, and the support is difficult.

[0056] Original tunnel support plan: The length of the transport tunnel of the 31182 working face is 1056m, and it is excavated along the top and bottom plates of the 18# coal seam. The tunnel has an arched section, with a lower width of 4.0m, a middle height of 2.6m, a tunnel cross-sectional area of ​​9.38㎡, and a net cross-sectional area of ​​9.29㎡. Anchor Anchor cable + steel bar support beam joint support, anchor rods are arranged in eight rows, spacing × row spacing = 1.0m × 1.0m. Anchor cables are arranged every 3.0m along the strike, and three rows are arranged. Figure 4 shown.

[0057] Step 1: Advance reinforcement of transport lanes, such as Figure 5 30m before the working face is mined, a row of Pre-reinforced anchor cable 16 and one row The pre-reinforcement anchor rods are 15, with an anchor cable spacing of 1.0m. The pre-reinforcement anchor rods and anchor cable rows are 1.0m apart, and the anchor rod spacing is 1.0m. Then, two rows of anchor rods are added to the coal seam roof. 16 pre-reinforced anchor cables are installed with a spacing of 1.0m to prevent the rock strata from sliding down from the upper coal seam floor to the tunnel floor.

[0058] Step 2: Pre-dig a gap in the upper side of the transport tunnel and expand the cross section, such as Figure 6 As shown. According to the designed goaf-side tunnel section, the coal wall of the working face is advanced by 5m to 8m, and rough blasting excavation and manual trimming are adopted to achieve the goaf-side tunnel section and pre-digging gap working space required by the design. The gap width is 2.3m wide and 2.5m high. The pre-digging gap and reinforcement support are operated in parallel. Two rows of coal seams are added at the gap section Reinforce the anchor rods with 4 sides, the upper and lower rows of anchor rods are 0.5m away from the top and bottom plates, and two rows are set along the top plate of the gap. Reinforcement anchor cable 5, the distance between anchor cables and section is 1.0m, and the distance between anchor cables is 1.0m.

[0059] Step 3: Drill holes 6 for pressure relief in advance on the top plate of the transport tunnel, such as Figure 7 As shown. In the center of the pre-excavated gap coal seam roof, along the strike direction, with an angle of 45° to the coal seam dip, the roof pressure relief borehole 6 is arranged, the borehole depth is 8m, the spacing is 0.6m, the drill bit diameter is 36mm, the direction is vertical to the tunnel, the hole is sealed for 2.0m, and the charge is 6m. After the construction of the first I-beam rock blocking device is completed, charge is loaded before the support is moved, and blasting operation is carried out after the support is moved.

[0060] Step 4: The first barrier support, such as Figure 8 As shown. Under the protection of hydraulic support 7 No. 1 of the working face, first arrange I-beams 8 along the direction at a position not less than 1000mm above the bottom plate of the upper coal seam in the transport lane. The steel beams 8 are made of 11# I-beams with a spacing of 0.5m. The upper and lower ends of the I-beams 8 are fixed to the top and bottom plates of the coal seam with top anchors 18 and ground anchors 19 respectively to further increase the stability of the top and bottom plates. The top anchors 18 and ground anchors 19 are used and The threaded steel anchor rod has a column hole 20 of at least 0.2m dug at the lower end. Semi-round wood + metal mesh + waste rubber are used on the top of the I-beam 8 and tied and fixed with wire, which serves as a flexible cushion layer 10 to achieve the first barrier support for the collapsed gangue in the upper section of the goaf 9.

[0061] Step 5: Retractable modular tunnel support support, such as Fig. 9 As shown. On the side of the pre-excavated gap of the transport tunnel, a semi-circular arched retractable module tunnel protection bracket 11 is arranged along the strike, with a spacing of 0.8m. The retractable module tunnel protection bracket 11 is filled and blocked with a filling body 12 above and on the side. The filling body 12 is generally composed of a cement backboard and a woven bag filled with coal gangue; at the same time, the outside is sprayed and sealed to reduce the space between the retractable module tunnel protection bracket and the side of the tunnel, so that the retractable module tunnel protection bracket 11 is completely fitted with the tunnel to prevent air leakage in the goaf.

[0062] Step 6: Delayed reinforcement support, such as Fig.10 As shown in the figure, after the working face is mined, the transport tunnel is located at the edge of the goaf area of ​​the working face, and the goaf-retained tunnel is successfully used as the return air tunnel of the lower section. In order to prevent the roof of the goaf-retained tunnel from collapsing, a single hydraulic pillar 13 is used to lag behind the coal wall for a certain distance. Two rows of single hydraulic pillars 13 are arranged along the strike direction, arranged in the middle and right side of the tunnel, with a spacing of 1.5m. At the same time, when the length of the goaf-retained tunnel reaches 5m, it needs to be moved back. According to the deformation of the roof of the goaf-retained tunnel, the separation of the layers, the integrity and damage of the roof, the stability of the roof of the goaf-retained tunnel is comprehensively judged and divided into zones. The single hydraulic pillar 13 is withdrawn from the goaf-retained tunnel 50m behind, and the unstable area is supplemented with anchor cables, temporary single hydraulic pillars are erected, and other active reinforcement and stabilization support is carried out.

[0063] The method of the present invention solves the problems of difficulty in supporting the surrounding rock of the mining tunnel during coal seam mining in the longwall fully mechanized mining face in the direction of large-angle and steep coal seams, and the falling gangue of the working face roof will slide, roll and impact the lower tunnel, resulting in increased asymmetric deformation of the surrounding rock of the tunnel along the goaf and reduced stability of the tunnel support body. It effectively avoids safety accidents of the roof of the tunnel along the goaf and greatly improves the advancement speed of the longwall fully mechanized mining face in the steeply inclined coal seam.

[0064] The present invention is not limited to the above-mentioned embodiments. On the basis of the technical solution disclosed in the present invention, technicians in this field can make some substitutions and deformations to some technical features therein according to the disclosed technical content without creative labor, and these substitutions and deformations are all within the protection scope of the present invention.

Claims

1. A method for protecting the gob-side tunnel by unloading, supporting and filling in a fully-mechanized mining face in a steeply inclined coal seam, characterized in that: The following steps are involved: Arrange advance reinforcement anchor rods and advance reinforcement anchor cables at a certain interval in the transport lane, and conduct advance reinforcement of the lane along the goaf after mining a certain distance at the advance working face; According to the design section of the reserved lane, blast the pre-dig gap in the upper part of the transport lane to expand the section; add pre-dig gap reinforcement anchor rods and pre-dig gap reinforcement anchor cables at the coal wall and roof of the pre-dig gap section to reinforce and support the pre-dig gap; In the center of the pre-excavated notch coal seam roof, pressure relief blasting drill holes are arranged at a certain interval; The hydraulic support is set up on the working face, and the steel beams for blocking the coal seam are arranged at the bottom of the transport lane to form the first line of support for the goaf; the roof pressure relief blasting operation is carried out after the working face is moved; A retractable module tunnel protection support is arranged on the side of the pre-excavated gap of the transport tunnel. The top and side of the retractable module tunnel protection support are filled and blocked with local filling bodies, and the outer surface is sprayed and sealed to form the second barrier support of the goaf; After the working face is mined, the transport tunnel is located at the edge of the goaf area of ​​the working face. After the surrounding rock of the goaf-retained tunnel formed along the goaf enters the slow sinking and deformation zone, the single hydraulic support is gradually withdrawn and migrated, and a single column withdrawal area roof observation point is set; the lagging coal wall is supported by single hydraulic pillars at a certain distance.

2. The method for protecting the gob-side tunnel by unloading, supporting and filling in a fully-mechanized mining face of a steeply inclined coal seam according to claim 1 is characterized in that: Advance reinforcement anchor rods and advance reinforcement anchor cables are arranged at intervals of 1.0 to 1.5 m on the lower side of the transport lane floor and the lane roof.

3. The method for protecting the gob-side tunnel by unloading, supporting and filling in a fully-mechanized mining face of a steeply inclined coal seam according to claim 1 is characterized in that: A gap is pre-dug by blasting on the upper side of the transport tunnel. The width of the gap is 1m to 1.5m and the height is the thickness of the coal seam.

4. The method for protecting the gob-side tunnel by unloading-supporting-filling coordination in a fully-mechanized mining face of a steeply inclined coal seam according to claim 1 is characterized in that: The arrangement spacing and row spacing of the pre-dig gap reinforcement anchor rods and pre-dig gap reinforcement anchor cables are 1.0m×1.0m, and metal mesh and steel support beams are used to reinforce and support the pre-dig gap.

5. The method for protecting the gob-side tunnel by unloading-supporting-filling coordination in a fully-mechanized mining face of a steeply inclined coal seam according to claim 1 is characterized in that: In the center of the pre-excavated notch coal seam roof along the strike direction, set the blasting position and blasting point spacing at a certain angle inclined toward the working face, arrange blasting top cutting and pressure relief drilling holes, and the drilling depth reaches above the basic top of the coal seam.

6. The method for protecting the gob-side tunnel by unloading-supporting-filling coordination in a fully-mechanized mining face of a steeply inclined coal seam according to claim 1 is characterized in that: At the bottom plate of the upper coal seam in the transport tunnel, rock-retaining steel beams are arranged along the strike direction using top anchors and ground anchors, the rock-retaining steel beams are fixed to the top and bottom plates of the coal seam, and a flexible cushion layer is set above the rock-retaining steel beams.

7. The method for protecting the gob-side tunnel by unloading, supporting and filling in a fully-mechanized mining face of a steeply inclined coal seam according to claim 5 is characterized in that The flexible cushion layer is made of half-round wood + metal mesh + waste rubber and is tied and fixed with wire to achieve the first barrier against rock bursting.

8. The method for protecting the gob-side tunnel by unloading-supporting-filling coordination in a fully-mechanized mining face of a steeply inclined coal seam according to claim 1 is characterized in that: The local filling body is composed of cement backboard and woven bags filled with coal gangue.

9. The method for protecting the gob-side tunnel by unloading-supporting-filling coordination in a fully-mechanized mining face of a steeply inclined coal seam according to claim 1, characterized in that: In the stable area, the single hydraulic support is completely withdrawn, and in the unstable area, additional anchor cables are installed and temporary single units are erected to actively reinforce and stabilize the support.

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