Near-distance coal seam 110 construction method roadway forming method

Abstract

The invention discloses a short-distance coal seam 110 construction method roadway forming method, and belongs to the technical field of coal mining, the short-distance coal seam comprises an upper coal seam and a lower coal seam, and the specific steps are as follows: calculating a roof cutting height: firstly calculating a theoretical value of the roof cutting height, and then calculating an actual value of the roof cutting height based on the theoretical value of the roof cutting height; the roadway roof is reinforced according to the actual value of the roof cutting height; performing top-cutting dense drilling according to the actual value of the top-cutting height; supporting in a roadway of a roadway-forming dynamic pressure area; and according to the actual value of the roof cutting height, supporting in the roadway of the roadway forming stable area. By the adoption of the method, through coal-pillar-free mining, remaining coal pillars of a close-distance coal seam can be omitted, coal pillar resources originally wasted in mining can be removed, the problem of stress concentration of the coal pillars is solved, the damage situation of interlayer rock masses is greatly improved, and the adverse mine pressure influence on mining of a lower coal seam is greatly reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of coal mining, and in particular to a method for forming a roadway using a close-range coal seam 110 construction method. Background Art

[0002] Close-distance coal seams usually refer to coal seams where the upper and lower coal seams have a greater impact on each other during the mining of multiple coal seams. Such coal seams occupy an important position in China's coal resources and are widely distributed. At present, the traditional 121 coal mining method is widely used in my country's coal resource mining. This method requires two tunnels to be excavated in advance for one working face, and a protective coal pillar is left between adjacent working faces. The coal pillar resources are seriously wasted, and the tunnel excavation volume is large, which can easily cause tension in mining and excavation. In the process of 121 mining of close-distance coal seams, after the upper coal seam is mined, the coal pillar, as the main bearing structure, bears a large force from the roof, resulting in stress concentration, causing large-scale rock damage between the upper and lower coal seams. Moreover, after the transmission effect of the coal pillar stress through the interlayer rock mass, it will also have an adverse impact on the mining of the lower coal seam, which can easily lead to safety accidents in the working face and tunnel of the lower coal seam.

[0003] The longwall mining 110 method is a new type of coal pillar-free mining technology that uses directional top cutting to change the bearing structure of the tunnel roof and optimize the stress environment of the tunnel surrounding rock. The longwall mining 110 method only requires one tunnel to be excavated in advance to mine a working face, and no protective coal pillars are left between adjacent working faces, which greatly improves the coal recovery rate and solves the problems of large tunnel excavation volume and tight mining and excavation succession.

[0004] However, the application of the 110 longwall mining method in close-range coal seams is not yet mature. During the implementation of the 110 method in close-range coal seams, the impact energy generated by traditional blasting and cutting will further increase the degree of damage to the interlayer rock mass. At the same time, when the blasting position is close to the goaf of the upper coal seam, it is very easy to cause water seepage, leakage of harmful gases, and even gas explosions. In addition, when mining the upper coal seam, the advanced support stress and lateral support stress of the working face cause damage and destruction to the interlayer rock mass. When the 110 method is used in the lower coal seam, the damaged roadway roof is very likely to have safety accidents such as support system failure and roof collapse.

[0005] Therefore, it is urgent to develop a method for tunneling in close-range coal seams using the 110 construction method. Summary of the invention

[0006] The purpose of the present invention is to provide a 110 method for tunneling in a close-range coal seam. Through pillar-free mining, the remaining coal pillars in the close-range coal seams can be eliminated, the originally wasted coal pillar resources can be recovered, and the problem of stress concentration in the coal pillars can be solved, which greatly improves the damage and destruction of the interlayer rock mass and significantly reduces the adverse mine pressure impact on the lower coal seam during mining.

[0007] To achieve the above-mentioned purpose, the present invention provides a method for forming a roadway in a close-distance coal seam 110, wherein the close-distance coal seam includes an upper coal seam and a lower coal seam, and the specific steps include:

[0008] S1, calculating the top cutting height, first calculating the theoretical value of the top cutting height, and then calculating the actual value of the top cutting height based on the theoretical value of the top cutting height;

[0009] S2. Reinforce the tunnel roof according to the actual value of the top cutting height;

[0010] S3. After the tunnel roof reinforcement is completed, the top cutting intensive drilling is carried out according to the actual value of the top cutting height;

[0011] S4. After the dense top cutting drilling is completed, the tunnel dynamic pressure zone is supported;

[0012] S5. Carry out tunnel support in the stable zone of the tunnel according to the actual value of the cutting top height.

[0013] Preferably, the theoretical value of the top cutting height in step S1 is determined according to the amount of tunnel roof subsidence, the amount of bottom heave, the mining height and the rock mass expansion coefficient, and the formula is:

[0014]

[0015] In the formula, H 理论 is the theoretical top cutting height; M is the mining height; H1 is the roof subsidence; H2 is the bottom heave; K is the roof rock mass expansion coefficient;

[0016] The actual value of the cutting top height is determined according to the relationship between the theoretical cutting top height, the minimum thickness required for the formation of the basic top of the interlayer rock mass, and the thickness of the interlayer rock mass. The formula is:

[0017]

[0018] In the formula, H 实际 is the actual cutting top height; D is the minimum thickness required for the basic top formation of the interlayer rock mass; C is the thickness of the interlayer rock mass.

[0019] Preferably, in step S2, reinforcing the tunnel roof according to the actual value of the top cutting height includes:

[0020] When H 实际 =H 理论 When the tunnel roof is reinforced, the constant resistance anchor cable support method is used;

[0021] When H 实际 =C, deep hole and shallow hole stereo grouting and constant resistance anchor support are used to reinforce the tunnel roof.

[0022] Preferably, the top cutting and dense drilling in step S3 includes two methods: cross dense drilling and top cutting and parallel dense drilling and top cutting. The cross dense drilling and top cutting method arranges forward drilling and reverse drilling respectively, and the parallel dense drilling and top cutting method only arranges the same direction drilling.

[0023] Preferably, the in-tunnel support in the dynamic pressure zone of the tunnel in step S4 includes: adopting two in-tunnel support forms, namely, gangue retaining support and setting up high working resistance unit brackets, to carry out in-tunnel support in the dynamic pressure zone of the tunnel.

[0024] Preferably, in step S5, performing tunnel support in the tunnel stability zone according to the actual value of the top cutting height includes:

[0025] When H 实际 =H 理论 When there is a relatively stable basic roof structure, the high working resistance unit support is gradually removed, and only the rock retaining support is retained to support the stable area of ​​the tunnel;

[0026] When H 实际 =C, there is no relatively stable basic top structure, and single pillars, π-shaped beams and rock retaining supports are used to support the stable area of ​​the tunnel.

[0027] Therefore, the present invention adopts the above-mentioned close-distance coal seam 110 construction method to form a lane, which has the following beneficial effects:

[0028] (1) The 110 method is used to achieve pillar-free mining, which can eliminate the remaining coal pillars in the upper coal seams at a close distance, greatly improve the coal resource recovery rate, solve the problem of stress concentration in the coal pillars, greatly improve the damage and destruction of the interlayer rock mass, and greatly reduce the adverse impact of mine pressure on the mining of the lower coal seams;

[0029] (2) Use three-dimensional grouting technology to repair and reinforce the damaged roof of the tunnel to restore the integrity of the roof rock mass, and use constant resistance anchor reinforcement technology to anchor the roof of the tunnel to enhance its bearing capacity and ensure the safety and stability of the tunnel surrounding rock during the mining process;

[0030] (3) Use two dense drilling arrangements, cross and parallel, to carry out dense drilling for top cutting, so as to reduce the disturbance effect of top cutting on the interlayer rock mass of coal seams in close proximity and ensure the safety of the top cutting process.

[0031] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 A schematic diagram of close-range coal seam mining according to an embodiment of the present invention;

[0033] Figure 2 This is a flow chart of a lane forming method according to an embodiment of the present invention;

[0034] Figure 3 It is a cross-sectional view of the tunnel roof reinforcement and top cutting when the actual value of the top cutting height is equal to the theoretical value of the top cutting height in the embodiment of the present invention;

[0035] Figure 4 This is a cross-sectional view of the tunnel roof reinforcement and top cutting when the actual value of the top cutting height is equal to the thickness of the interlayer rock mass in the embodiment of the present invention;

[0036] Figure 5 This is a schematic diagram of cross-dense drilling and top cutting according to an embodiment of the present invention;

[0037] Figure 6 This is a schematic diagram of cutting tops of parallel dense drilling according to an embodiment of the present invention;

[0038] Figure 7 It is a cross-sectional view of the support in the tunnel in the dynamic pressure zone of the tunnel when the actual value of the top cutting height is equal to the theoretical value of the top cutting height in the embodiment of the present invention;

[0039] Figure 8 It is a cross-sectional view of the support in the tunnel in the dynamic pressure zone of the tunnel when the actual value of the top cutting height is equal to the thickness of the interlayer rock mass in the embodiment of the present invention;

[0040] Fig. 9 It is a cross-sectional view of the support in the lane in the stable zone of the lane when the actual value of the top cutting height is equal to the theoretical value of the top cutting height in the embodiment of the present invention;

[0041] Fig.10 It is a cross-sectional view of the support in the lane in the stable zone of the lane when the actual value of the top cutting height is equal to the theoretical value of the top cutting height in the embodiment of the present invention;

[0042] Reference numerals

[0043] 1. Upper coal seam; 2. First mining working face of upper coal seam; 3. Upper coal seam tunnel; 4. Continuation working face of upper coal seam; 5. Lower coal seam; 6. First mining working face of lower coal seam; 7. Lower coal seam tunnel; 8. Continuation working face of lower coal seam; 9. Basic roof; 10. Constant resistance anchor cable; 11. Deep hole; 12. Shallow hole; 13. Drilling; 131. Forward drilling; 132. Reverse drilling; 133. Same direction drilling; 14. Gangue retaining support; 15. High working resistance unit bracket; 16. Single pillar; 17. π-shaped beam. DETAILED DESCRIPTION

[0044] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. The components of the embodiments of the present invention generally described and shown in the drawings here can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the claimed invention, but merely represents selected embodiments of the present invention. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0045] The present invention provides a method for forming a roadway in a close-distance coal seam 110, wherein the close-distance coal seam includes an upper coal seam 1 and a lower coal seam 5, and the mining method thereof is as follows: Figure 1 As shown, the upper coal seam 1 is mined first. When the first mining face 2 of the upper coal seam is mined, the upper coal seam roadway 3 is left. After the mining of the first mining face 2 of the upper coal seam is completed, the upper coal seam roadway 3 is reused for the mining of the upper coal seam follow-up face 4, and the mining of the upper coal seam is completed in sequence. After the mining of the upper coal seam is completed, the lower coal seam 5 is mined. The mining sequence is consistent with that of the upper coal seam. First, the first mining face 6 of the lower coal seam is mined, and at the same time, the lower coal seam roadway 7 is left. After the mining of the first mining face 6 of the lower coal seam is completed, the lower coal seam roadway 7 is reused for the mining of the lower coal seam follow-up face 8, and the mining of all lower coal seams is completed in sequence.

[0046] like Figure 2 As shown, the specific steps of the roadway forming method of the close-distance coal seam 110 method include:

[0047] Cutting height calculation

[0048] First, a theoretical value of the top cut height is calculated, and then an actual value of the top cut height is calculated based on the theoretical value of the top cut height.

[0049] The theoretical value of the cutting height is determined based on the tunnel roof subsidence, floor heave, mining height and rock mass expansion coefficient, and the formula is:

[0050]

[0051] In the formula, H 理论 is the theoretical top cutting height; M is the mining height; H1 is the roof subsidence; H2 is the bottom heave; K is the roof rock mass expansion coefficient;

[0052] The actual value of the cutting top height is determined according to the relationship between the theoretical cutting top height, the minimum thickness required for the formation of the basic top of the interlayer rock mass, and the thickness of the interlayer rock mass. The formula is:

[0053]

[0054] In the formula, H 实际 is the actual cutting top height; D is the minimum thickness required for the basic top formation of the interlayer rock mass; C is the thickness of the interlayer rock mass.

[0055] Roadway roof reinforcement

[0056] The tunnel roof is reinforced according to the actual value of the top cutting height.

[0057] When H 实际 =H 理论 When Figure 3 As shown, when a roadway is left in a close-range coal seam, there is a relatively stable basic roof 9 structure, and the roadway roof is reinforced by a constant resistance anchor cable 10 support method, and the constant resistance anchor cable should be anchored into the basic roof 9 rock layer.

[0058] When H 实际 =C, if Figure 4 As shown, there is no relatively stable basic roof 9 structure when leaving a roadway in a close-range coal seam, and the roadway roof is greatly affected by the disturbance caused by mining in the upper coal layer and has poor mechanical properties. In order to ensure safe roadway retention, deep hole 11 shallow hole 12 three-dimensional grouting and constant resistance anchor cable 10 support methods are used to reinforce the roadway roof.

[0059] Dense drilling and cutting

[0060] After the tunnel roof reinforcement is completed, the dense drilling technology is used to carry out dense drilling 13 of the top cutting 50m away from the leading working face according to the actual value of the top cutting height. Figure 3 , 4 shown.

[0061] The top cutting intensive drilling 13 is divided into two types: cross-intensive drilling top cutting and parallel-intensive drilling top cutting, respectively. Figure 5 and Figure 6 As shown, the cross-dense drilling and cutting method arranges forward drilling holes 131 and reverse drilling holes 132 respectively, so that multiple holes are connected in series to form a surface, thereby enhancing the cutting effect of dense drilling, and the parallel dense drilling and cutting method only arranges the same direction drilling holes 133, so that multiple holes are parallel to form a surface, ensuring the cutting effect of dense drilling. The drilling angles of the forward drilling holes 131, the reverse drilling holes 132, and the same direction drilling holes 133 can be flexibly selected according to the site conditions.

[0062] In-tunnel support in dynamic pressure zone of tunnel

[0063] After the dense top cutting drilling is completed, two types of in-tunnel support, namely, rock retaining support 14 and setting up high working resistance unit brackets 15, are used to carry out in-tunnel support in the dynamic pressure zone of the tunnel.

[0064] As the working face is mined, the roof of the goaf behind the working face begins to collapse. At this time, the tunnel is within the dynamic pressure zone of the tunnel. The tunnel support conditions in this area are as follows: Figure 7 , Figure 8 As shown, support is performed in the tunnel dynamic pressure zone. A rock retaining support 14 is arranged on the goaf side of the tunnel in the dynamic pressure zone of the tunnel. The rock retaining support 14 can effectively prevent the goaf gangue from rushing into the tunnel and form a stable gravel tunnel wall structure with the goaf gangue. A high working resistance unit support 15 is used in the tunnel to support the tunnel roof to ensure the safety of the tunnel during the collapse of the goaf roof in the dynamic pressure zone of the tunnel and the periodic pressure.

[0065] In-tunnel support in stable zone of tunnel

[0066] According to the actual value of the top cutting height, the internal support of the roadway in the stable zone is carried out. As the working face continues to advance, the gangue in the goaf is compacted and stabilized, and the surrounding rock of the roadway gradually stabilizes. At this time, the roadway is within the stable zone of the roadway.

[0067] When H 实际 =H 理论 When the tunnel is stable, the tunnel support is as follows: Fig. 9 As shown, there is a relatively stable basic roof 9 structure. According to the monitoring of the mine pressure and the deformation of the tunnel, the high working resistance unit support can be gradually removed, and only the rock retaining support 14 is retained to support the stable area of ​​the tunnel.

[0068] When H 实际 = C, the support in the stable zone of the tunnel is as follows Fig.10 As shown, there is no relatively stable basic roof 9 structure. According to the monitoring of mine pressure and tunnel deformation, single pillars 16, π-shaped beams 17 and rock retaining supports 14 can be used to support the stable zone of the tunnel to fully ensure the safety of the tunnel during the tunnel retention and reuse stage.

[0069] Therefore, the present invention adopts the above-mentioned method of forming a lane in a close-distance coal seam 110. Through pillar-free mining, it can eliminate the remaining coal pillars in the close-distance coal seams, recover the originally wasted coal pillar resources, and solve the problem of stress concentration in the coal pillars, greatly improve the damage and destruction of the interlayer rock mass, and significantly reduce the adverse mine pressure impact on the lower coal seam during mining.

[0070] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that they can still modify or replace the technical solution of the present invention with equivalents, and these modifications or equivalent replacements cannot cause the modified technical solution to deviate from the spirit and scope of the technical solution of the present invention.

Claims

1. A method for forming a roadway in a close-distance coal seam 110, characterized in that: Close-range coal seams include upper coal seams and lower coal seams. The specific steps include: S1, calculating the top cutting height, first calculating the theoretical value of the top cutting height, and then calculating the actual value of the top cutting height based on the theoretical value of the top cutting height; S2. Reinforce the tunnel roof according to the actual value of the top cutting height; S3. After the tunnel roof reinforcement is completed, the top cutting intensive drilling is carried out according to the actual value of the top cutting height; S4. After the dense top cutting drilling is completed, the tunnel dynamic pressure zone is supported; S5. Carry out tunnel support in the stable zone of the tunnel according to the actual value of the cutting top height.

2. A method for forming a roadway in a close-distance coal seam 110 according to claim 1, characterized in that: The theoretical value of the top cutting height in step S1 is determined according to the tunnel roof subsidence, bottom heave, mining height and rock mass expansion coefficient, and its formula is: In the formula, H 理论 is the theoretical top cutting height; M is the mining height; H1 is the roof subsidence; H2 is the bottom heave; K is the roof rock mass expansion coefficient; The actual value of the cutting top height is determined according to the relationship between the theoretical cutting top height, the minimum thickness required for the formation of the basic top of the interlayer rock mass, and the thickness of the interlayer rock mass. The formula is: In the formula, H 实际 is the actual cutting top height; D is the minimum thickness required for the basic top formation of the interlayer rock mass; C is the thickness of the interlayer rock mass.

3. A method for forming a roadway in a close-distance coal seam 110 according to claim 2, characterized in that: In step S2, reinforcing the tunnel roof according to the actual value of the top cutting height includes: When H 实际 =H 理论 When the tunnel roof is reinforced, the constant resistance anchor cable support method is used; When H 实际 =C, deep hole and shallow hole stereo grouting and constant resistance anchor support are used to reinforce the tunnel roof.

4. A method for forming a roadway in a close-distance coal seam 110 according to claim 1, characterized in that: The top cutting and dense drilling in step S3 includes two methods: cross-drilling and top cutting and parallel-drilling. The cross-drilling and top cutting method arranges forward drilling and reverse drilling respectively, and the parallel-drilling and top cutting method only arranges drilling in the same direction.

5. The method for forming a roadway in a close-distance coal seam 110 according to claim 1 is characterized in that: The step S4 includes: performing tunnel support in the dynamic pressure zone of the tunnel by adopting two tunnel support forms: using rock blocking support and setting up high working resistance unit brackets.

6. A method for forming a roadway in a close-distance coal seam 110 according to claim 2, characterized in that: In step S5, the tunnel support in the tunnel stability zone is performed according to the actual value of the top cutting height, including: When H 实际 =H 理论 When there is a relatively stable basic roof structure, the high working resistance unit support is gradually removed, and only the rock retaining support is retained to support the stable area of ​​the tunnel; When H 实际 =C, there is no relatively stable basic top structure, and single pillars, π-shaped beams and rock retaining supports are used to support the stable area of ​​the tunnel.

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