Mining-supporting-filling-coal-pillar-free integrated collaborative mining method for fully mechanized coal mining face

Abstract

The invention provides a mining-supporting-filling-coal-pillar-free integrated collaborative mining method for a fully mechanized coal mining face, and belongs to the technical field of coal mining. The problems of low mining efficiency and difficult ventilation in the existing coal-pillar-free filling mining are solved; comprising the following steps that a haulage roadway and an auxiliary haulage roadway are tunneled on a first stope face, a flexible formwork concrete wall is poured on one side, adjacent to a second stope face, of the haulage roadway of the first stope face and evaluated, and contact holes are reserved every 20-30 m when the flexible formwork concrete wall is poured; an auxiliary transportation roadway is excavated on the second stope face along the flexible formwork concrete wall, meanwhile, a transportation roadway is excavated on the other side of the second stope face, and a ventilation system is arranged; longwall working face filling coal-pillar-free mining is conducted on the first stoping working face, and parallel operation of stoping, supporting, filling and entry retaining is achieved; a filling system and a pipeline are arranged in the auxiliary transportation roadway of the second stope face; the method is applied to fully mechanized coal mining face mining.

Description

Technical Field

[0001] The invention provides a comprehensive mining face mining-support-filling-coal pillar-free integrated coordinated mining method, belonging to the technical field of coal mining. Background Art

[0002] The non-pillar filling mining technology can effectively solve the problem of coal residue in goaf areas, greatly improve the recovery rate of coal resources, avoid stress concentration in the underlying coal seam, and reduce safety accidents caused by coal pillar instability. The commonly used non-pillar filling mining method is technically difficult, and the concrete wall is prefabricated during the mining period. The process is complicated, the process is multi-step, and the speed is slow, which affects the efficient operation of the mining face.

[0003] On the other hand, pillarless backfill mining has the problem of difficulty in ventilation to a certain extent due to the complexity of the air path opening and the insufficient airtightness of the backfill body caused by the elimination of coal pillars, which leads to the ventilation system being unable to fully follow the tunnels and artificially designed air paths for ventilation. Summary of the invention

[0004] In order to solve the problems of low mining efficiency and difficult ventilation in existing non-coal pillar filling mining, the present invention proposes a comprehensive mining face mining-support-filling-coal pillar-free integrated collaborative mining method.

[0005] The technical solution adopted by the present invention is: a comprehensive mining face mining-support-filling-coal pillar-free integrated collaborative mining method, comprising the following steps: S10: excavate the transport tunnel and auxiliary transport tunnel at the first mining face, cast the flexible formwork concrete wall on the side of the transport tunnel of the first mining face adjacent to the second mining face and evaluate the flexible formwork concrete wall. When casting the flexible formwork concrete wall, leave a contact hole every 20-30m for ventilation and filling operations; S20: excavate an auxiliary transport tunnel along the flexible concrete wall at the second mining face, and at the same time excavate a transport tunnel on the other side of the second mining face, and choose to arrange the ventilation system according to the actual ventilation needs and tunnel conditions; Multiple contact holes connect the transport tunnel of the first mining face with the auxiliary transport tunnel of the second mining face to form a joint air intake path; S30: Longwall working face filling without coal pillar mining is carried out on the first mining working face to realize parallel operation of mining-support-filling-retaining lanes; S40: A filling system and pipelines are laid out in the auxiliary transport tunnel of the second mining face, and the reserved contact holes are used as filling ports to deliver the filling slurry to the filling area, and the contact holes where the filling work has been completed are grouting-sealed.

[0006] Furthermore, the flexible formwork concrete wall includes a flexible compression-resistant part, a base and a tension anchor assembly. The base is integrally formed and the side walls are covered with a metal mesh. The tension anchor assembly is installed through the base, and the metal mesh is fixed to the side wall of the base by the tension anchor assembly.

[0007] Furthermore, in step S10, the strength and width of the flexible formwork concrete wall are evaluated by the following method: The mechanical equilibrium equation after tunneling is established, and the expression is as follows: ; In the above formula: f 0 is the support force of the flexible formwork concrete wall; f 1 is the coal support force in the loose area of ​​the roadway; f 2 is the supporting force of the filling body on the roof; b is the width of the flexible formwork concrete wall; x 0 is the width of the loose area of ​​the lane side; l is the length of the filling body acting on the roof; the roof includes the direct roof and the basic roof; d 1 is the bulk density of the basic top; d 2 is the bulk density of the direct top; m 1 is the thickness of the basic top; m 2 is the thickness of the direct top; L 1 is the hanging length of the top plate; L 2 is the length of the uniform load; q is the overburden force; According to the elastic foundation beam theory, the supporting force of the filling body on the direct top and the basic top is: ; make f 1 is equal to the residual compressive strength of the coal body in the loose area of ​​the roadway s c ; and considering the stress concentration factor or , then the support force of the flexible formwork concrete wall is f 0 is represented by: ; In the formula x The expression for 0 is: ; In the above formula: c is the lateral pressure coefficient; m is the thickness of the coal seam; d' is the average bulk density of the overlying rock; f is the internal friction angle of the interface between the coal seam and the roof and floor; c It is the cohesion of the interface between the coal seam and the roof and floor; H The depth of the coal seam to be mined; Based on the on-site investigation, the support force of the flexible formwork concrete wall was calculated. f 0, compared with the design value of concrete axial compressive strength p c Select the appropriate concrete type and design the appropriate flexible formwork concrete wall width b ; The design value of concrete axial compressive strength p c and flexible concrete wall width b The following conditions are met: f 0> p c b ; Verify the required bearing capacity of the flexible formwork concrete wall. The flexible formwork concrete wall bearing capacity consists of two components: the constrained reinforcement flexible formwork and the core self-compacting concrete. F The calculation formula is: ; In the above formula: F is the bearing capacity of the flexible formwork concrete wall; is the stability factor of the component; p c is the design value of concrete axial strength; s r It is the effective restraining force generated by the action of the anchor bolt hoop; is the longitudinal cross-sectional area of ​​the flexible formwork concrete wall; in s r The expression is as follows: ; In the above formula: r is the anchor radius; s b is the design value of anchor bolt tensile strength; d 1. d 2 are the spacing and row spacing of anchor bolts respectively.

[0008] Furthermore, the ventilation system in step S20 is divided into two different systems according to the role of the transport tunnel of the first mining face in ventilation: a two-inlet and two-outlet ventilation system and a three-inlet and one-outlet ventilation system.

[0009] Furthermore, the structure of the two-in-two-return ventilation system is: The auxiliary transport tunnel of the first mining face and the transport tunnel of the second mining face are used as air intake tunnels to provide air supply, the transport tunnel of the first mining face and the auxiliary transport tunnel of the second mining face are used as return air tunnels to provide air return, and air regulating equipment is installed at the end of the auxiliary transport tunnel of the second mining face.

[0010] Furthermore, the structure of the three-in-one-return ventilation system is: The first mining face transport tunnel, the first mining face auxiliary transport tunnel and the second mining face transport tunnel are used as air intake tunnels to provide air supply, the second mining face auxiliary transport tunnel is used as return air tunnel to provide air return, and air regulating equipment is installed at the end of the second mining face auxiliary transport tunnel.

[0011] Furthermore, fans are provided at the inlet of the air inlet lane and the outlet of the return air lane; and air ducts connected to the fans are provided in the lanes of the air inlet lane and the return air lane.

[0012] Furthermore, in step S30, cemented filling is used for the filling of the longwall working face in pillar-free mining. The gangue is crushed by the ground gangue crushing and slurry preparation system, mixed with the required materials in a certain proportion, and then water is added and stirred to form a filling slurry. The prepared filling slurry is delivered to the underground through the pipeline in the vertical slurry conveying hole, and the slurry prepared from coal gangue is transported to the filling area by pipeline.

[0013] Furthermore, in step S40, while the first mining face is being mined, the nearest contact hole is used as the filling port of the filling pipeline. After the filling work of the contact hole is completed, it is grout-sealed and the next contact hole is activated as the filling port to ensure the airtightness between the filling body and the flexible formwork concrete wall.

[0014] Furthermore, during the filling process of step S40, the width of the goaf is not greater than 20 m.

[0015] The beneficial effects of the present invention compared with the prior art are as follows: The invention provides a comprehensive mining face mining-support-filling-coal pillar-free integrated collaborative mining method, which excavates a transport tunnel and an auxiliary transport tunnel at the first mining face, and evaluates and casts a flexible formwork concrete wall on the side of the transport tunnel of the first mining face adjacent to the second mining face. When casting the flexible formwork concrete wall, a contact hole is left every 20 to 30 meters, and then an auxiliary transport tunnel is excavated along the wall at the second mining face, and a transport tunnel is excavated on the other side of the second mining face. The invention improves the mining speed and work efficiency of the working face by adjusting the flexible formwork concrete wall from the original side along the air to the middle of the two mining faces, and changing the mining process from the original wall construction while mining to the casting of the flexible formwork concrete wall in advance in the early stage of mining.

[0016] The integrated collaborative mining method of mining-support-filling-coal pillar-free in the comprehensive mining face provided by the present invention forms a joint air inlet path between the first mining face and the second mining face through a connecting hole, and can flexibly select two ventilation systems, a two-inlet and two-return ventilation system and a three-inlet and one-return ventilation system, according to the mine conditions. This avoids the situation in which the ventilation system cannot fully follow the tunnel and the artificially designed air path for ventilation due to the elimination of coal pillars in coal-pillar-free filling mining, and the difficulty in ventilation caused by it is complicated.

[0017] The integrated collaborative mining method of mining-support-filling-coal pillar-free in the comprehensive mining face provided by the present invention adjusts the filling pipeline in the filling method from the original transport tunnel to the filling system and pipeline arranged in the auxiliary transport tunnel of the second mining face adjacent to the mining tunnel, and delivers the filling slurry to the filling area, so as to replace the means of arranging the filling pipeline in the mining tunnel and the working face in the prior art, without the need to repeatedly arrange and disassemble the filling pipeline. The problem of narrow working space in the tunnel during mining of the mining face, which affects efficient operation, is avoided. Moreover, the filling operation, support operation and working face mining operation do not affect each other, thereby achieving the "cooperative-undisturbed" parallel operation of integrated mining-support-filling-coal pillar-free in the longwall working face. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The present invention will be further described below in conjunction with the accompanying drawings: Figure 1 It is a flow chart of the integrated collaborative mining method of mining-supporting-filling-coal pillar-free in a fully mechanized mining face according to an embodiment of the present invention; Figure 2 A schematic diagram of a mechanical model for evaluating a flexible formwork concrete wall according to an embodiment of the present invention; Figure 3 A schematic diagram of the structure of a flexible formwork concrete wall and a cross-hole according to an embodiment of the present invention; Figure 4 A schematic diagram of a two-inlet and two-outlet ventilation system according to an embodiment of the present invention; Figure 5 Schematic diagram of a three-in-one-return ventilation system according to an embodiment of the present invention.

[0019] In the figure: 1. Transport tunnel of the first mining face; 2. Auxiliary transport tunnel of the first mining face; 3. Transport tunnel of the second mining face; 4. Auxiliary transport tunnel of the second mining face; 5. Flexible formwork concrete wall; 6. Contact hole; 7. First mining face; 8. Second mining face; 9. Filling area; 10. Adjustment window; 11. Filling pipeline; 12. Flexible pressure-resistant parts; 13. Base; 14. Tension anchor assembly; 15. Overlying rock formation. DETAILED DESCRIPTION

[0020] like Figure 1 to Figure 5As shown, the present invention provides a comprehensive mining face mining-support-filling-coal pillar-free integrated collaborative mining method, comprising the following steps: S10: parallel to the direction of the coal seam to be mined, excavate an auxiliary transportation tunnel at the first mining face 7 for transporting materials, supplying air or returning air to the first mining face 7; at the same time, excavate a transport tunnel for transporting coal and supplying air to the first mining face 7.

[0021] A flexible formwork concrete wall 5 is cast on one side of the auxiliary transport tunnel 2 of the first mining face adjacent to the second mining face 8 and evaluated. When the flexible formwork concrete wall 5 is cast, a contact hole 6 is set every 20 to 30 meters.

[0022] S20: excavate an auxiliary transport tunnel along the flexible formwork concrete wall 5 at the second mining face for transporting materials and taking in air to the second mining face 8, and at the same time excavate a transport tunnel on the other side of the second mining face 8, and select and arrange the ventilation system according to the actual ventilation needs and tunnel conditions.

[0023] S30: Longwall working face filling and pillar-free mining is carried out on the first mining working face 7 to realize the integrated “coordinated-non-disturbance” parallel operation of “mining-support-filling-lane retention”.

[0024] S40: Lay out a filling system and pipelines in the auxiliary transport tunnel of the second mining working face, and use the reserved contact holes 6 as filling ports to deliver the filling slurry to the filling area 9, and perform grouting and sealing on the contact holes 6 where the filling work has been completed.

[0025] In one embodiment of the present invention, before the working face is mined in step S10, a first mining face transport tunnel 1 is excavated on a side of the first mining face 7 away from the second mining face 8, and a first mining face auxiliary transport tunnel 2 is excavated on a side of the first mining face 7 adjacent to the second mining face 8, and at the same time, a flexible formwork concrete wall 5 is cast on a side of the first mining face auxiliary transport tunnel 2 close to the second mining face 8 and evaluated.

[0026] It is worth noting that the selection of the spacing between the cross-holes 6 needs to be considered according to the mine pressure and ventilation conditions. For areas with low mine pressure conditions and good tunnel stability, the spacing between the cross-holes 6 can be maintained at about 20 to 25 meters to meet basic ventilation and filling material transportation needs. In areas with high mine pressure, in order to prevent the mine pressure from exerting concentrated stress on the flexible formwork concrete wall 5, the spacing between the cross-holes 6 should be set to 25 to 30 meters as much as possible. By reducing the density of the cross-holes 6 and increasing the spacing between the cross-holes 6 to reduce damage to the structure of the flexible formwork concrete wall 5, the structural pressure caused by the concentration of mine pressure can be better dispersed, the risk of rupture of the flexible formwork concrete wall 5 can be reduced, and the construction efficiency can be improved. At the same time, in order to ensure effective ventilation of the tunnel and the working surface, the spacing between the cross-holes 6 also needs to be adjusted according to the width and height of the tunnel to avoid ventilation dead corners and uneven ventilation.

[0027] A plurality of contact holes 6 connect the auxiliary transport tunnel 2 of the first mining face with the transport tunnel 3 of the second mining face to form a joint air inlet path.

[0028] Based on the above embodiments, Figure 3 As shown, the flexible formwork concrete wall 5 includes a flexible compression member 12, a base 13 and a tension anchor assembly 14. The base 13 is integrally formed and the side walls are covered with metal mesh. The tension anchor assembly 14 is installed through the base 13, and the metal mesh is fixed to the side wall of the base 13 by the tension anchor assembly 14. The tension anchor assembly 14 includes an anchor rod, an anchor rod support plate, a self-aligning ball pad and a nut. The anchor rod support plate, the self-aligning ball pad and the nut are sequentially arranged along the length direction of the anchor rod. A certain pre-tightening force is applied to the anchor rod by the tension anchor assembly 14 to ensure the stability of the base 13. The flexible compression member 12 is installed between the base 13 and the overlying rock layer 15 (top plate).

[0029] In one embodiment of the present invention, the strength and width of the flexible formwork concrete wall 5 need to be evaluated by calculation; specifically, the method for evaluating the strength and width of the flexible formwork concrete wall 5 is as follows: Establish the mechanical balance equation after tunnel excavation, and its model is as follows Figure 2 As shown: ; In the above formula: f 0 is the support force of the flexible formwork concrete wall, in kN / m 2 ; f 1 is the coal support force in the loose area of ​​the roadway, in kN / m 2 ; f 2 is the support force of the filling body on the roof (including the direct roof and the basic roof), in kN / m 2 ; b is the width of the flexible formwork concrete wall, in m; x0 is the width of the loose zone of the lane side, in m; l is the length of the filling body acting on the roof, in meters; d 1 is the bulk density of the basic top, in kN / m 3 ; d 2 is the bulk density of the direct top, in kN / m 3 ; m 1 is the thickness of the basic top, in m; m 2 is the thickness of the immediate roof, in m; L 1 is the hanging length of the top plate, in meters; L 2 is the length of the uniform load, in m; q is the overburden force, unit is kN.

[0030] Figure 2 middle a is the tunnel width. In this embodiment, the evaluation calculation of the flexible formwork concrete wall 5 does not require the tunnel width.

[0031] According to the elastic foundation beam theory, the supporting force of the filling body on the direct top and the basic top is: .

[0032] f 1 is equal to the residual compressive strength of the coal body in the loose area of ​​the roadway s c ; and considering the stress concentration factor or , flexible formwork concrete wall support f 0 can be represented as: ; In the formula x The expression for 0 is: ; In the above formula: c is the lateral pressure coefficient; m is the thickness of the coal seam, in m; d' is the average bulk density of the overlying rock layer, in kN / m 3 ; f is the internal friction angle of the interface between the coal seam and the roof and floor, in degrees; c is the cohesion of the interface between the coal seam and the roof and floor, in MPa; H It is the buried depth of the mined coal seam, in meters.

[0033] According to the on-site investigation, the support force of the flexible formwork concrete wall can be calculated as follows: f 0, compared with the design value of concrete axial compressive strength p c Select the appropriate concrete type and design the appropriate flexible formwork concrete wall width b. Design value of concrete axial compressive strength when designing flexible formwork concrete wall 5 p c and flexible concrete wall width b The following conditions must be met: f 0> p c b .

[0034] Required bearing capacity for flexible formwork concrete wall 5 F Verify the bearing capacity of flexible concrete walls F It consists of two parts: a constrained reinforced flexible formwork and a core self-compacting concrete. The bearing capacity of the flexible formwork concrete wall is F The calculation formula is: ; In the above formula: F is the bearing capacity of the flexible formwork concrete wall, in kN; is the stability factor of the component; p c is the design value of concrete axial strength, in MPa; s r It is the effective restraining force generated by the anchor bolt hoop, in MPa; is the longitudinal section area of ​​the flexible formwork concrete wall, in m 2 ; in s r The expression is as follows: ; In the above formula: r is the radius of the anchor bolt, in mm; s b is the design value of anchor bolt tensile strength, in MPa; d 1. d 2 are the spacing and row spacing of anchor bolts, in mm.

[0035] The supporting force of the flexible formwork concrete wall 5 is obtained according to the above calculation method, and then the corresponding specifications are consulted to select concrete with appropriate axial compressive strength to cast the flexible formwork concrete wall 5 of a set width. The flexible formwork concrete wall 5 should pay attention to sealing, and a contact hole 6 should be set every 20m.

[0036] In one embodiment of the present invention, in step S20, a second mining face transport tunnel 3 is excavated on one side of the second mining face 8 close to the flexible concrete wall 5. A plurality of contact holes 6 connect the first mining face auxiliary transport tunnel 2 and the second mining face transport tunnel 3 to form a joint air intake path. A second mining face auxiliary transport tunnel 4 is excavated on the other side of the second mining face 8 and is used for return air during the mining period of the first mining face 7, and the ventilation path arrangement is now completed.

[0037] On the basis of the above scheme, it is worth noting that the ventilation system can be divided into two different systems according to the role of the first mining face transport tunnel 1 in ventilation: a two-in-two-return ventilation system and a three-in-one-return ventilation system.

[0038] In one embodiment of the present invention, a two-inlet and two-outlet ventilation system is formed in step S20. Figure 4 As shown, the auxiliary transport lane 2 of the first mining face and the transport lane 3 of the second mining face serve as air intake lanes, and the transport lane 1 of the first mining face and the auxiliary transport lane 4 of the second mining face serve as return air lanes. Due to the mining of the first mining face 7, the difference between its air volume and that of the second mining face 8 gradually increases. Therefore, in order to ensure reasonable ventilation, air conditioning equipment needs to be installed at the tail end of the auxiliary transport lane 4 of the second mining face 8. Furthermore, fans are installed at the inlet of the air intake lane and the outlet of the return air lane; wind tubes connected to fans are installed in the lanes of the air intake lane and the return air lane to ensure underground ventilation and keep the concentration of dangerous gases within a safe range.

[0039] In one embodiment of the present invention, a three-inlet and one-return ventilation system is formed in step S20. Figure 5 As shown, the first mining face transport tunnel 1, the first mining face auxiliary transport tunnel 2, and the second mining face transport tunnel 3 serve as air intake tunnels, and the second mining face auxiliary transport tunnel 4 serves as a return air tunnel. Furthermore, fans are provided at the inlet of the air intake tunnel and the outlet of the return air tunnel; wind tubes connected to the fans are provided in the tunnels of the air intake tunnel and the return air tunnel to ensure underground ventilation and keep the concentration of dangerous gases within a safe range.

[0040] It should be noted that the ventilation system should be selected based on the actual ventilation needs and lane conditions. Different ventilation systems have different advantages and disadvantages and applicable scopes. For example, the two-in-two-return ventilation system has strong airflow stability. Inlet and return air channels are set in different lanes to form two parallel U-shaped loops, which can achieve stable one-way airflow and reduce airflow turbulence; the inlet and return air are completely separated, which can avoid gas cross-contamination between the working area and the filling area 9, and help maintain fresh air quality. However, under certain circumstances, the two-in-two-return ventilation system requires higher air adjustment operations, especially when the lane resistance or ventilation volume demand changes, it is necessary to add fans or adjust wind windows to maintain balance.

[0041] The three-in-one-return ventilation system is highly flexible. It uses alternating inlet and return ducts to form three main channels. Through alternating inlet and return ducts, the ventilation volume of each channel can be adjusted according to site needs. It is suitable for local adjustment or short-distance ventilation, can quickly adapt to changes in mine conditions, and is convenient for rapid ventilation adjustment, especially in areas where temporary ventilation changes are required. However, due to the alternating arrangement of the inlet and return ducts, the airflow of the three-in-one-return ventilation system is prone to backflow in the junction area, resulting in uneven ventilation effect and affecting air quality.

[0042] In one of the embodiments of the present invention, in step S30, longwall face filling and coal pillar-free mining is performed on the first mining face 7. On the basis of the above scheme, it should be noted that the embodiment of the present invention proposes a longwall face filling and coal pillar-free mining method, in which the filling operation, support operation and face mining operation are carried out simultaneously without affecting each other, so as to realize the integrated "cooperative-non-disturbance" parallel operation of "mining-support-filling-retaining lanes" of the longwall face.

[0043] Longwall working face filling without coal pillar mining uses cemented filling, and the gangue is crushed and mixed with cement, fly ash, etc. in a certain proportion through the ground gangue crushing and slurry preparation system, and then water is added to stir to make filling slurry. The prepared filling slurry is delivered to the underground through the pipeline in the vertical slurry delivery hole, and the slurry prepared from coal gangue is transported to the filling area 9 by pipeline transportation.

[0044] On the basis of the above, in order to achieve "cooperative-non-disturbance" parallel operation, in step S40, the filling operation is carried out by adjusting the means of arranging the filling pipeline in the mining tunnel and the working face in the prior art, and the filling system and pipeline are arranged in the transport tunnel 3 of the second mining working face, and the nearest contact hole 6 serves as the filling port, and the filling slurry is sent to the filling area 9. During the filling process, the width of the goaf should be ensured to be no more than 20m, so that the position of the filling port and the filling area 9 can correspond to each other on the premise of ensuring the safety of the goaf. After the filling work is completed, the contact hole 6 is promptly grout-sealed, and the next contact hole 6 is activated as the filling port to ensure the airtightness of the filling area 9, keep the goaf completely isolated, and ensure the rationality of the air path. During the mining operation on the working face, the contact hole 6 takes over as the filling port as the working face advances, and the filling operation, support operation and working face mining operation do not interfere with each other, thereby achieving "cooperative-non-disturbance" parallel operation.

[0045] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A comprehensive mining face mining-support-filling-coal pillar-free integrated collaborative mining method, characterized in that: The following steps are involved: S10: excavate the transport tunnel and auxiliary transport tunnel at the first mining face, cast the flexible formwork concrete wall on the side of the transport tunnel of the first mining face adjacent to the second mining face and evaluate the flexible formwork concrete wall. When casting the flexible formwork concrete wall, leave a contact hole every 20-30m for ventilation and filling operations; S20: excavate an auxiliary transport tunnel along the flexible concrete wall at the second mining face, and at the same time excavate a transport tunnel on the other side of the second mining face, and choose to arrange the ventilation system according to the actual ventilation needs and tunnel conditions; Multiple contact holes connect the transport tunnel of the first mining face with the auxiliary transport tunnel of the second mining face to form a joint air intake path; S30: Longwall working face filling without coal pillar mining is carried out on the first mining working face to realize parallel operation of mining-support-filling-retaining lanes; S40: A filling system and pipelines are laid out in the auxiliary transport tunnel of the second mining face, and the reserved contact holes are used as filling ports to deliver the filling slurry to the filling area, and the contact holes where the filling work has been completed are grouting-sealed.

2. The integrated mining method of mining-supporting-filling-coal pillar-free in a fully mechanized mining face according to claim 1 is characterized in that: The flexible formwork concrete wall comprises a flexible compression member, a base and a tension anchor assembly. The base is integrally formed and the side walls are covered with a metal mesh. The tension anchor assembly is installed through the base, and the metal mesh is fixed to the side wall of the base by the tension anchor assembly.

3. The integrated mining method of mining-supporting-filling-coal pillar-free in a fully mechanized mining face according to claim 2 is characterized in that: In step S10, the strength and width of the flexible formwork concrete wall are evaluated by the following method: The mechanical equilibrium equation after tunneling is established, and the expression is as follows: ； In the above formula: f 0 is the support force of the flexible formwork concrete wall; f 1 is the coal support force in the loose area of ​​the roadway; f 2 is the supporting force of the filling body on the roof; b is the width of the flexible formwork concrete wall; x 0 is the width of the loose area of ​​the lane side; l is the length of the filling body acting on the roof; the roof includes the direct roof and the basic roof; δ 1 is the bulk density of the basic top; δ 2 is the bulk density of the direct top; m 1 is the thickness of the basic top; m 2 is the thickness of the direct top; L 1 is the hanging length of the top plate; L 2 is the length of the uniform load; q is the overburden force; According to the elastic foundation beam theory, the supporting force of the filling body on the direct top and the basic top is: ； make f 1 is equal to the residual compressive strength of the coal body in the loose area of ​​the roadway σ c ; and considering the stress concentration factor η , then the support force of the flexible formwork concrete wall is f 0 is represented by: ； In the formula x The expression for 0 is: ； In the above formula: γ is the lateral pressure coefficient; m is the thickness of the coal seam; δ' is the average bulk density of the overlying rock; φ is the internal friction angle of the interface between the coal seam and the roof and floor; c It is the cohesion of the interface between the coal seam and the roof and floor; H The depth of the coal seam to be mined; Based on the on-site investigation, the support force of the flexible formwork concrete wall was calculated. f 0, compared with the design value of concrete axial compressive strength p c Select the appropriate concrete type and design the appropriate flexible formwork concrete wall width b ; The design value of concrete axial compressive strength p c and flexible concrete wall width b The following conditions are met: f 0＞ p c b ； Verify the required bearing capacity of the flexible formwork concrete wall. The flexible formwork concrete wall bearing capacity consists of two components: the constrained reinforcement flexible formwork and the core self-compacting concrete. F The calculation formula is: ； In the above formula: F is the bearing capacity of the flexible formwork concrete wall; is the stability factor of the component; p c is the design value of concrete axial strength; σ r It is the effective restraining force generated by the action of the anchor bolt hoop; is the longitudinal section area of ​​the flexible formwork concrete wall; in σ r The expression is as follows: ； In the above formula: r is the anchor radius; σ b is the design value of anchor bolt tensile strength; d 1. d 2 are the spacing and row spacing of anchor bolts respectively.

4. The integrated mining method of mining-supporting-filling-coal pillar-free in a fully mechanized mining face according to claim 1 is characterized in that: The ventilation system in step S20 is divided into two different systems according to the role of the transport tunnel of the first mining face in ventilation: a two-inlet and two-outlet ventilation system and a three-inlet and one-outlet ventilation system.

5. The integrated mining method of mining-supporting-filling-coal pillar-free in a fully mechanized mining face according to claim 4 is characterized in that: The structure of the two-in-two-return ventilation system is: The auxiliary transport tunnel of the first mining face and the transport tunnel of the second mining face are used as air intake tunnels to supply air, the transport tunnel of the first mining face and the auxiliary transport tunnel of the second mining face are used as return air tunnels to return air, and air regulating equipment is installed at the end of the auxiliary transport tunnel of the second mining face.

6. The integrated mining method of mining-supporting-filling-coal pillar-free in a fully mechanized mining face according to claim 4 is characterized in that: The structure of the three-in-one-return ventilation system is: The first mining face transport tunnel, the first mining face auxiliary transport tunnel and the second mining face transport tunnel are used as air intake tunnels to provide air supply, the second mining face auxiliary transport tunnel is used as return air tunnel to provide air return, and air regulating equipment is installed at the end of the second mining face auxiliary transport tunnel.

7. A comprehensive mining face mining-support-filling-coal pillar-free integrated collaborative mining method according to claim 5 or 6, characterized in that: Fans are installed at the inlet of the air inlet lane and the outlet of the return air lane; wind ducts connected to the fans are installed in the lanes of the air inlet lane and the return air lane.

8. The integrated mining method of mining-supporting-filling-coal pillar-free in a fully mechanized mining face according to claim 1 is characterized in that: In step S30, cemented filling is used for filling the longwall working face in pillar-free mining. The gangue is crushed by the ground gangue crushing and slurry preparation system, mixed with the required materials in a certain proportion, and then water is added and stirred to form a filling slurry. The prepared filling slurry is delivered to the underground through the pipeline in the vertical slurry conveying hole, and the slurry prepared from coal gangue is transported to the filling area by pipeline.

9. The integrated mining method of mining-supporting-filling-coal pillar-free in a fully mechanized mining face according to claim 8 is characterized in that: In step S40, while the first mining face is being mined, the nearest contact hole is used as the filling port of the filling pipeline. After the filling work of the contact hole is completed, it is grout-sealed and the next contact hole is activated as the filling port to ensure the airtightness between the filling body and the flexible formwork concrete wall.

10. The integrated coordinated mining method of mining-supporting-filling-coal pillar-free in a fully mechanized mining face according to claim 9, characterized in that: During the filling process of step S40, the width of the goaf is not greater than 20m.

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