A method for developing a mine field without large roadway protective coal pillars for deep coal seam mining

Abstract

The present invention is applicable to the technical field of coal mine mining, and provides a mine field development method without gateway protection coal pillars for deep coal seam mining. Along multiple designed gateways and the corresponding gateway coal pillar protection areas, longwall fully mechanized mining faces that can completely cover this area are arranged for mining. The loose space of gangue that has not fully caved within the range affected by the support of the coal walls on both sides of the goaf is backfilled to form a stable isolation belt that isolates the goaf. After that, multiple gateways with a stable period of decades are arranged at the positions where the floor stress of the goaf is reduced and the rock stratum strength is relatively high, so as to solve the control problem of continuous large deformation of deep gateways. The subsequent working face sectional roadways are driven obliquely upward from the gateway, cross the stable backfilled isolation belt and then enter the coal seam, and continue to drive to form a working face, which directly mines until the stable backfilled isolation belt, eliminating the problem of setting gateway protection coal pillars, and greatly reducing the influence of strong disturbance during stop mining on the stability of gateway surrounding rocks.

Description

Technical Field

[0001] The present invention belongs to the technical field of coal mining, and particularly relates to a mine field development method without gateway protective coal pillars for deep coal seam mining. Background Art

[0002] In the high-stress environment of deep coal seams, it is difficult to maintain the gateways, and there are often support problems such as large deformation and strong rheology. In fact, the haulage gateway and the return air gateway, as the development gateways of the mine, have a service life of more than ten years to several decades, so it is necessary to maintain the stability of the gateways for a long time.

[0003] At present, the cost of maintaining the stability of the gateway surrounding rock in some deep mines is as high as that of excavating a new gateway. It can be seen that it is difficult to maintain the long-term stability of deep gateways only by methods such as expanding and repairing. According to the traditional selection of the gateway layout position, generally, the haulage gateway and the return air gateway are set in the floor rock stratum of the coal seam group. When the mining depth is not large, they can also be set in the coal seam with hard coal quality and stable surrounding rock at the bottom of the coal seam group.

[0004] In existing deep mines, basically the gateways are all in the stable floor rock stratum of the coal seam. However, due to the existence of protective coal pillars above the gateway roof, the mechanical transmissibility of the rock stratum is good. When the gateway coal pillars are disturbed by coal mining, a large support pressure is generated, which is bound to affect the stress stability of the surrounding rock of the rock roadway below, causing interference and damage to the support of the gateway. In actual sites, leaving large-scale gateway protective coal pillars in the deep environment not only fails to play a role in maintaining the stability of the gateway support, but also wastes a large amount of raw coal, seriously affecting the recovery rate of deep coal seams. Summary of the Invention

[0005] The purpose of the embodiments of the present invention is to provide a mine field development method without gateway coal pillars for deep coal seam mining, aiming to solve the problems existing in the prior art determined in the background art.

[0006] The embodiments of the present invention are implemented as follows. A mine field development method without gateway coal pillars for deep coal seam mining includes the following steps:

[0007] Step 1: After determining the scope of the industrial square protective coal pillars at the initial stage of deep coal seam development, arrange longwall fully mechanized mining faces that can completely cover this area along the designed multiple gateways and the corresponding gateway coal pillar protection areas;

[0008] Step 2: During the coal mining process of the working face, fill the loose space of the gangue that has not fully caved within the influence range of the coal wall support on both sides of the goaf to form a stable isolation zone between the goaf and the coal body;

[0009] Step 3: Arrange multiple gateways at the positions where the floor stress of the goaf is reduced and the rock stratum is intact;

[0010] Step 4: The subsequent mining face is excavated from the main tunnel upward, passing through the stable filling isolation zone and entering the coal seam, and then excavated along the coal seam to form a working face;

[0011] Step 5: When mining at the subsequent working face, directly mine to the stable filling isolation zone, so as to realize the mining without stopping the coal pillar at the deep coal seam working face, and thus eliminate the problem of setting up coal pillars for protection in the main tunnel;

[0012] Step 6: Repeat steps 4 and 5 to construct a continuous succession working face until the coal seam is mined.

[0013] The embodiment of the present invention provides a method for developing a coal-pillar-free mine field for deep coal seam mining. On the basis of determining the range of the coal pillars for protection of the deep coal seam development tunnels, a longwall fully mechanized mining face that can completely cover the range of this area is arranged along the designed multiple large tunnels and the corresponding large tunnel coal pillar protection areas for mining, and the loose space of gangue that has not fully collapsed within the influence range of the coal wall support on both sides of the goaf is filled to form a stable isolation zone that isolates the goaf. Afterwards, multiple large tunnels with a stability period of several decades are arranged in the stress reduction area of ​​the goaf floor and the position with high rock strength, so as to solve the problem of controlling the continuous large deformation of the deep large tunnels; the subsequent mining working face section tunnel is inclined upward from the large tunnel, crosses the stable filling isolation zone and enters the coal seam, and continues to excavate to form a working face. This working face is directly mined to the stable filling isolation zone, eliminating the problem of leaving the protective coal pillars in the large tunnels, and greatly reducing the influence of strong disturbance on the stability of the surrounding rock of the large tunnel when mining is stopped. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a flow chart of the steps of the method for developing a coal field without large lanes for deep coal seam mining according to the present invention;

[0015] Figure 2 A plan view of the layout of the preliminary working face tunnels for deep coal seam development according to the present invention;

[0016] Figure 3 It is a plan view of the early longwall working face mining of the deep coal seam of the present invention;

[0017] Figure 4 It is a cross-sectional view of the connection relationship between the subsequent long wall working face and the main tunnel of the deep coal seam of the present invention;

[0018] Figure 5 It is a plan view of the connection relationship between the subsequent long wall working face and the main tunnel of the deep coal seam of the present invention;

[0019] Figure 6 This is the expected plan view of deep coal seam mining without large coal pillars according to the present invention.

[0020] In the attached figure: 1-main shaft; 2-auxiliary shaft; 3-return air shaft; 4-coal bunker at the bottom of the shaft; 5-parking lot at the bottom of the shaft;

[0021] 6 - Industrial square protection coal pillar; 7 - Main haulage roadway; 8 - Auxiliary haulage roadway; 9 - Return airway; 10 - Haulage roadway; 11 - Haulage gateway; 12 - Return air gateway; 13 - Return airway; 14 - Heading face; 15 - Crossheading; 16 - Goaf; 17 - Longwall face; 18 - Filling body; 19 - Bunker; 21 - Transition roadway. Detailed implementation manners

[0022] In order to make the objectives, technical solutions and advantages of the present invention clearer and more understandable, the present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0023] The following describes the specific implementation of the present invention in detail in conjunction with specific embodiments.

[0024] As Figure 1 shown, it is a flowchart of a method for developing a mine field without large roadway coal pillars for deep coal seam mining provided by an embodiment of the present invention. The method includes:

[0025] Step 1: After determining the range of the industrial square protection coal pillar in the initial stage of deep coal seam development, arrange longwall fully mechanized mining faces that can completely cover this area along the designed multiple roadways and the corresponding large roadway coal pillar protection areas;

[0026] Step 2: During the coal mining process of the working face, fill the loose space of the gangue that has not fully caved within the influence range of the coal wall support on both sides of the goaf to form a stable isolation belt between the goaf and the coal body;

[0027] Step 3: Arrange multiple roadways at the positions where the floor stress of the goaf is reduced and the rock strata are intact. Multiple roadways with a stable period of decades can be arranged at the positions where the floor stress of the goaf is reduced and the rock strata have relatively high strength and good integrity;

[0028] Step 4: The subsequent mining working face gateways are driven obliquely upward from the roadway, cross the stable filling isolation belt and then enter the coal seam, and then drive along the coal seam to form a working face;

[0029] Step 5: During the coal mining of the subsequent working face, directly mine to the stable filling isolation belt, realizing the non-stop coal pillar mining of the deep coal seam working face, and thus eliminating the problem of leaving large roadway protection coal pillars;

[0030] Step 6: Repeat Step 4 and Step 5 to realize the construction of continuous replacement working faces until the coal seam mining is completed.

[0031] The embodiments of the present invention grasp the geological environment characteristics of deep coal seams, abandon the idea of seeking long-term stable support for main roadways in such a harsh environment, think about problems from the source of deep mine field development, and according to the characteristic that stress reduction areas will be formed under the goaf during the mining of deep working faces to achieve pressure relief, propose an exploration method of mining first and then arranging roadways, that is, a mining method that can both realize the pre-mining of main roadway coal pillars and enable the main roadways to avoid being affected by high stress so as to achieve long-term stability.

[0032] As a preferred embodiment of the present invention, in step 1: As Figure 2 shown in the plan view of the roadway layout of the early-stage working face for deep coal seam exploration, change the traditional exploration method. After determining the scope of the main roadway protection coal pillar L 1, directly enter the coal seam from the roadway of the shaft bottom yard for tunneling and transportation, and the return airway, drive the working face crossheading along the direction parallel to the designed main roadway, and then arrange fully mechanized longwall mining working faces that can completely cover this area along the designed multiple main roadways and the corresponding main roadway coal pillar protection areas, where:

[0033] (1) Design the number of main roadways according to the designed production capacity of the mine, and determine the scope of the protection coal pillar. The scope of the main roadway protection coal pillar should be greater than the sum of the lateral stress influence areas of each deep roadway, that is: ;

[0034] In the formula —The scope of the main roadway protection coal pillar;

[0035] —The number of designed main roadways in the mine;

[0036] —The designed spacing of the main roadways in the mine;

[0037] —The designed width of the main roadway;

[0038] —The lateral stress influence distance of the main roadway.

[0039] (2) The layout length of the working face allowed by the coal and rock geological structure is delimited by the geological exploration situation, mainly avoiding large fault tectonic zones; the maximum required length of the working face equipment needs to be determined by equipment selection based on the basic conditions of the root coal seam, the general situation of the working face and the selection of coal mining technology, etc.; the calculated length of the working face to ensure the ventilation air volume obtained from the air volume calculation .

[0040] (3) The principle of arranging the first mining working face is to completely cover the pre-designed main roadways and the scope of the main roadway protection coal pillars. Under various restrictive factors, there will be a range for the length of the first mining working face: , ensuring that the first mining face covers all the coal pillars in the main tunnel while meeting all conditions and restrictions.

[0041] (4) Working face layout length allowed by coal rock geological structure The maximum required length of the working face equipment is determined by geological exploration conditions to avoid encountering large fault structural zones. The equipment selection is determined by the basic conditions of the fibrous coal seam, the general conditions of the working face and the selection of coal mining technology, and the calculated length of the working face to ensure the ventilation air volume is calculated by the air volume calculation. , in satisfying After the working surface length requirement, the actual working surface length It needs to be determined based on the economic benefits of the inclined roadway from the main roadway into the coal seam and the inclination requirements of the inclined transition section from the rock roadway to the coal roadway: first determine the inclination and position of the inclined transition section that meets the equipment requirements, then select the length and position of the rock roadway section and the coal roadway section, and calculate the economic excavation of the roadway in the coal roadway section and the rock roadway section, and achieve the economic optimum while meeting the allowable inclination of the equipment, so as to finally determine .

[0042] (5) The first mining face should cover the designed length of the main tunnel as much as possible in terms of advancement length. If conditions permit, it can extend to the boundary of the mining area. Figure 5 As shown; if the length of the main tunnel is too long or there is an obvious turn, which exceeds the longest advancement distance or maximum turning angle of the working face under this geological condition, the method of arranging the working face in sections can be adopted, that is, the subsequent pressure relief and tunnel protection working face can be arranged when the mining of the first section of the working face is near the end.

[0043] (6) The advancement length of the first mining working face on one side should cover the designed length of the main tunnel on that side as much as possible, and can extend to the boundary of the mining area if conditions permit.

[0044] (7) Developing early coal transportation routes in deep coal seams:

[0045] 14- Excavation working face → 11- Transport chute / 12- Return air chute → 10- Transport tunnel → 7- Main transport tunnel → 4- Coal bunker at the bottom of the shaft → 1- Main shaft.

[0046] (8) Early ventilation routes for deep coal seam development:

[0047] Return air chute excavation: 1-main shaft → 7-main transport tunnel → 10-transport tunnel → 12-return air chute → 14-excavation working face → 12-return air chute → 13-return air tunnel → 3-return air shaft;

[0048] Transport gateway driving: 1 - main shaft → 7 - main haulage roadway → 10 - transport roadway → 11 - transport gateway → 14 - driving face → 11 - transport gateway → 8 - auxiliary haulage roadway → 2 - auxiliary shaft.

[0049] As another preferred embodiment of the present invention, as Figure 3 shown in the plan view of the early longwall face mining in deep coal seams, during the face mining process, the loose space of the gangue that has not fully caved within the influence range of the support of the coal walls on both sides of the goaf is filled to form a stable isolation zone between the goaf and the coal body, namely 18 - filling body. Among them:

[0050] (1) The requirements for the filling isolation zone are as follows: First, the width should be greater than the horizontal distance from the outer roadway to the coal wall of the first mined face on its side to ensure that the inclined section of the subsequent working face gateway from the roadway to the coal seam is below it; Second, the structure is complete, with good stability and sufficient strength to support the overlying broken main roof.

[0051] (2) The purposes of the filling isolation zone are as follows: First, it isolates the goaf to prevent the connection between this goaf and the subsequent mining working face and the influx of harmful gases from the goaf into the working face; Second, it serves as the stop line for the subsequent working face, and the face stops advancing when it reaches here.

[0052] (3) Since the subsequent working face gateway needs to pass through the filling isolation zone to enter the coal body, it is required that the filling body structure is compact and stable, with high strength and good filling integrity. Therefore, when arranging the grouting, it can be divided into two parts. One part is the strengthened grouting for the dense filling area. This area ensures the approach and entry of the later inclined roadway. The width of this part of the filling zone should be greater than the width of the area of the arc - shaped triangular block of the main roof on the side of the working face. Two grouting and filling pipelines can be laid here for enhanced filling, or other filling methods can be selected according to the actual situation; The other part is the conventional filling area, where one filling pipeline can be laid, and the strength of the filling body is sufficient to support the overlying broken roof.

[0053] (4) Coal haulage route for the early longwall face mining in deep coal seams:

[0054] 17 - mining face → 11 - transport gateway → 10 - transport roadway → 7 - main haulage roadway → 4 - bottom coal bunker → 1 - main shaft.

[0055] (5) Ventilation route for the early longwall face mining in deep coal seams:

[0056] 1 - main shaft / 2 - auxiliary shaft → 7 - main haulage roadway / 8 - auxiliary haulage roadway → 10 - transport roadway → 11 - transport gateway → 17 - mining face → 12 - return airway → 13 - return roadway → 3 - return shaft.

[0057] As another preferred embodiment of the present invention, Step 3: As shown in the sectional view of the connection relationship between the subsequent longwall working face and the main roadway in the deep coal seam Figure 4 , where:

[0058] (1) Arrange multiple main roadways with a stable period of several decades in the stress reduction area of the goaf floor and at positions where the rock formation has relatively high strength and good integrity. The distance between the main roadway and the goaf floor above should comprehensively consider the depth of the stress reduction area of the goaf floor caused by mining and the mechanical properties of the floor rock formation to ensure that and the main roadway is located in a hard rock formation with good integrity.

[0059] (2) The roadway and its support system should avoid the floor fracture zone generated by the mined coal seam, that is, the distance between the main roadway and the goaf is greater than the depth of the floor fracture zone , so the actual distance between the main roadway position and the goaf floor is: , and within this range, the roadway and its support system should be as close as possible to the goaf floor to make the pressure relief effect most obvious.

[0060] (3) Since the goaf floor is severely disturbed by mining, there will inevitably be certain crack development in the area where the main roadway is arranged at the bottom. The main roadway should be strengthened in support, and it is recommended to use grouting to support the fractured surrounding rock mass; at the same time, local air leakage prevention measures should be taken according to the actual surrounding rock quality to ensure the ventilation stability of the main roadway.

[0061] (4) The sectional roadway of the subsequent mining working face is driven obliquely upward from the main roadway. After crossing the stable filling isolation belt, it enters the coal seam, and then drives along the coal seam to form a working face. The inclination angle of the transportation and return air headings of this working face in the transition section from the main roadway to the coal seam should strictly follow the requirements for the normal operation of equipment such as belt conveyors:

[0062]

[0063] In the formula: — The horizontal distance of the transition section from the main roadway to the coal seam;

[0064] — The vertical distance of the transition section from the main roadway to the coal seam;

[0065] — The actual inclination angle of the roadway in the transition section;

[0066] — The allowable inclination angle of equipment such as belt conveyors.

[0067] (5) The transition section from the main roadway to the coal seam should be controlled as much as possible below the filling isolation belt, and the transition roadway should be strengthened in support; at the same time, the end of the transition section should be realized within the filling isolation belt to ensure that the filling body is used as the stop line when the subsequent working face is advanced and mined.

[0068] As another preferred embodiment of the present invention, in step 4, after the main roadway of the floor is connected to the subsequent longwall working face, the subsequent work can carry out coal mining operations, where:

[0069] (1) As shown in the plan view of the connection relationship between the subsequent longwall working face of the deep coal seam and the main roadway, when the subsequent working face is mined, it is directly mined to the stable filling isolation zone, realizing the mining of the working face without large roadway coal pillars and without stopping coal pillars in the deep coal seam, and greatly reducing the disturbance of the deep main roadway caused by the mining of the working face. Figure 5

[0070] (2) The coal transportation route for the subsequent longwall working face in the deep coal seam:

[0071] 17 - Mining working face → 11 - Transportation gateway → 19 - Bunker → 7 - Main transportation roadway → 4 - Bunker at the bottom of the shaft → 1 - Main shaft.

[0072] (3) The ventilation route for the subsequent longwall working face in the deep coal seam:

[0073] 1 - Main shaft / 2 - Auxiliary shaft → 7 - Main transportation roadway / 8 - Auxiliary transportation roadway → 11 - Transportation gateway → 17 - Mining working face → 12 - Return airway → 9 - Return roadway → 13 - Return air roadway → 3 - Return air shaft.

[0074] (4) The coal transportation route for the subsequent driving working face in the deep coal seam:

[0075] 14 - Driving working face → 11 - Transportation gateway → 19 - Bunker → 7 - Main transportation roadway → 4 - Bunker at the bottom of the shaft → 1 - Main shaft.

[0076] (5) The ventilation route for the subsequent driving working face in the deep coal seam:

[0077] 1 - Main shaft / 2 - Auxiliary shaft → 7 - Main transportation roadway / 8 - Auxiliary transportation roadway → 14 - Driving working face / 10 - Transportation roadway → 9 - Return roadway → 13 - Return air roadway → 3 - Return air shaft.

[0078] (6) As shown in the expected plan view of mining without large roadway coal pillars in the deep coal seam, the inclined rock roadway driven from the main roadway to the coal seam can be reused during the continuous replacement of the working face. That is, after entering the coal seam using this section of the rock roadway, a connecting roadway is driven along the direction parallel to the main roadway at a given distance of the coal pillar to realize the driving of the gateway of the next working face. Figure 5

[0079] (7) As shown in Figure 6 ​​As shown, continuous successive working faces are constructed in sequence from the main tunnels for mining until the coal seam is mined completely, thus realizing the main tunnel-free coal pillar mining operation in the entire mining area of ​​the deep coal seam.

[0080] As another preferred embodiment of the present invention, in step 6: the inclined tunnel excavated from the main tunnel to the coal seam can be reused when the subsequent working face takes over, that is, this section of the inclined tunnel from the main tunnel to the coal seam can still be used for the excavation of the next working face.

[0081] The above-mentioned embodiment of the present invention provides a method for developing a mine field without large tunnels and coal pillars for deep coal seam mining. The method abandons the idea of ​​seeking long-term and stable support for large tunnels in this harsh environment, considers the problem from the source of deep mine field development, and proposes a development method of first mining and then laying tunnels according to the characteristic that the deep working face mining will form a stress reduction zone below the goaf to achieve pressure relief, that is, a method of pre-mining large tunnel coal pillars and preventing the large tunnels from being affected by high stress to achieve long-term stability. The method is based on determining the range of coal pillar protection for deep coal seam development tunnels, and mining is carried out along the designed multiple large tunnels and corresponding large tunnel coal pillar protection areas. The longwall comprehensive mining face that can completely cover this area is arranged, and the loose space of gangue that has not fully collapsed within the influence range of the coal wall support on both sides of the goaf is filled to form a stable isolation zone that isolates the goaf. Afterwards, multiple large tunnels with a stability period of several decades are arranged in the stress reduction areas of the goaf floor and locations with high rock strength to solve the problem of controlling continuous large deformation of deep large tunnels; the tunnels in the subsequent mining working face section are excavated upward from the main tunnel, crossing the stable filling isolation zone and entering the coal seam, and continuing to excavate to form a working face. This working face is directly mined to the stable filling isolation zone, eliminating the problem of leaving protective coal pillars in the large tunnel and greatly reducing the impact of strong disturbances on the stability of the surrounding rock of the large tunnel when mining is stopped.

[0082] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A mine field development method without a large roadway protective coal pillar for deep coal seam mining, characterized in that, The steps include: Step 1: After the scope of the industrial square protection coal pillar is determined in the early stage of deep coal seam development, a longwall comprehensive mechanized mining working face that can completely cover this area is arranged along the designed multiple large tunnels and the corresponding large tunnel protection coal pillar protection areas; Step 2: During the mining process of the working face, the loose space of gangue that has not fully collapsed within the influence range of the coal wall support on both sides of the goaf is filled to form a stable filling isolation zone between the goaf and the coal body; Step 3: Arrange multiple large tunnels in the stress reduction area of ​​the goaf floor and the location of intact rock formation; Step 4: The subsequent mining face is excavated from the main tunnel upward, passing through the stable filling isolation zone and entering the coal seam, and then excavated along the coal seam to form a working face; Step 5: When mining at the subsequent working face, directly mine to the stable filling isolation zone, so as to realize the mining without stopping the coal pillar at the deep coal seam working face, and thus eliminate the problem of setting up coal pillars for protection in the main tunnel; Step 6: Repeat steps 4 and 5 to construct a continuous succession working face until the coal seam is mined.

2. The well - field development method without gateway protective coal pillars for deep coal seam mining according to claim 1, characterized in that, In step 1: a. Directly excavate the transportation and return air tunnels from the bottom of the mine to enter the coal seam, and then excavate the first mining face along the direction parallel to the designed large tunnel to form the first mining face, determine the number of large tunnels designed for the mine's designed production capacity, and determine the range of the large tunnel protection coal pillar. The range of the large tunnel protection coal pillar should be greater than the sum of the lateral stress influence areas of each deep tunnel, that is, ； In the formula — The total width of the main roadway and the protective coal pillar of the main roadway; — The number of main galleries in the mine design — The spacing of the main roadways in the mine design; — is the designed width of the main roadway; — Influence distance of lateral stress in main roadway; b. The first mining face needs to cover the range of the gateway protective coal pillar that encompasses all gateways, i.e., its length should be greater than the total width of the gateways and the gateway protective coal pillar , and is also limited by the layout length of the working face permitted by the coal and rock geological structure , the maximum required length of the working face equipment , and the calculated length of the working face to ensure the ventilation air volume ; c. After meeting the working face length requirement, the actual working face length needs to be determined according to the economic benefits of the inclined roadway entering the coal seam from the main roadway and the dip angle requirements of the inclined transition section from the rock roadway to the coal roadway. The economic calculations for the roadway excavation in the coal roadway section and the rock roadway section are carried out to achieve the best economy under the allowable dip angle of the equipment, and finally is determined. The principle of the first mining face layout is that it must completely cover the range of the pre-designed main roadway and the main roadway protective coal pillar. Under various restrictive factors, there will be a range for the actual working face length of the first mining face: , ensuring that the first mining face completely covers the main roadway protective coal pillar while meeting the restrictions of various conditions; d. The first mining face should extend as far as possible to cover the designed length of the main tunnel, and if conditions permit, it can extend to the boundary of the mining area; e. If the length of the main tunnel is too long according to the actual situation of the mining area, exceeding the longest advancement distance of the working face under such geological conditions, the method of arranging the working face in sections can be adopted. The subsequent pressure relief and tunnel protection working face can be arranged when the mining of the first section of the working face is nearing completion.

3. The well field development method without large roadway protective coal pillars for deep coal seam mining according to claim 2, characterized in that In step 2: a. The filling body serves as an isolation belt to prevent the gob area of the first mining face from communicating with the gob areas of subsequent conventional mining faces. It is required that the width of the stable filling isolation belt is greater than the horizontal length of the inclined roadway in the transition section from the main roadway to the coal seam to ensure that the inclined section of the subsequent working face's gateway from the main roadway to the coal seam is below it; b. Since the subsequent working face drift needs to pass through a stable filling isolation zone to enter the coal body, the filling structure is required to be compact and stable, with high strength and good filling integrity. Therefore, it can be divided into two parts when grouting is arranged. One part is the dense filling area for enhanced grouting. This area ensures the proximity and entry of the subsequent inclined tunnels. The other part is the conventional filling area, and the filling strength is sufficient to support the overlying broken roof.

4. The well - field development method without large - roadway protective coal pillars for deep coal seam mining according to claim 1, characterized in that, In step 3: a. The distance between the main roadway and the floor of the goaf of the first mining face The depth of the stress reduction zone in the floor of the goaf caused by mining should be comprehensively considered and the mechanical properties of the floor rock strata to ensure that the main roadway is in the hard rock strata with good integrity; b. The main roadway and its support system shall avoid the floor fracture zone generated by the mined coal seam, that is, the distance between the main roadway and the goaf shall be greater than the depth of the floor fracture zone ; c. As the floor of the goaf is severely disturbed by mining, it is inevitable that certain cracks will develop in the area where the main tunnel is arranged at the bottom. The support of the main tunnel should be strengthened and local measures should be taken to prevent air leakage.

5. The well - field development method for deep coal seam mining without large - roadway protective coal pillars as claimed in claim 4, wherein, The main roadway and its support system shall avoid the floor fracture zone generated by the mined coal seam, that is, the distance between the main roadway and the goaf shall be greater than the depth of the floor fracture zone. , so the actual distance between the main roadway and the floor of the goaf is: , and within this range, the main roadway and its support system shall be as close as possible to the floor of the goaf to make the pressure relief effect most obvious.

6. The well - field development method without large - drift protective coal pillars for deep coal seam mining according to claim 1, characterized in that, In step 4, the dip angle of the subsequent mining face conveyor and the return air heading in the transition section from the main roadway to the coal seam shall strictly comply with the requirements for the normal operation of the belt conveyor, that is , where is the horizontal and vertical distance of the transition section from the main roadway to the coal seam, and is also the width of the stable filling isolation belt and the layout depth of the main roadway, is the allowable dip angle of the belt conveyor.

7. The well field development method without large roadway protective coal pillars for deep coal seam mining according to claim 1, characterized in that In step 6: the inclined roadway excavated from the main roadway to the coal seam can be reused when the subsequent working face takes over, that is, this section of the inclined roadway entering the coal seam from the main roadway can still be used for the excavation of the next working face.

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