A method for reinforcing support of a roadway in a thin coal seam double roadway arrangement working face

Abstract

The application provides a reinforced supporting method for a thin coal seam double-roadway arrangement working face roadway reservation, and belongs to the technical field of roadway supporting of a fully-mechanized coal mining face in a coal mine underground. The method can realize safe, efficient and long-distance reinforced supporting of the surrounding rock of the roadway reservation under twice mining influences. The reinforced supporting device has the advantages of fast supporting speed, pressure bearing, high strength, recyclability and the like. The reinforced supporting device can provide a uniform initial active stress for the roof of the gob-side roadway reservation, and the stress can basically cover the roof within the roadway width range. The reinforced supporting, roadway bolt and anchor cable supporting jointly act, inhibit the development of the roof separation of the roadway, optimize the stress state of the surrounding rock of the roadway, slow down the stress of the overburden strata acting on the side of the roadway, the roadway bolt and anchor cable supporting and the temporary reinforced supporting jointly control the deformation of the surrounding rock of the roadway, and keep the integrity and stability of the surrounding rock of the roadway.

Description

Technical Field

[0001] This invention belongs to the technical field of roadway support for fully mechanized coal mining faces, and specifically discloses a method for strengthening roadway support in thin coal seams with double roadway layout. Background Technology

[0002] The dual-roadway layout is a common roadway arrangement in fully mechanized coal mining faces. A return airway, a haulage roadway, and an auxiliary haulage roadway are arranged on both sides of a longwall face. The haulage roadway and the auxiliary haulage roadway are arranged parallel to each other, with a certain width of coal pillar between them. After the current working face is mined out, the auxiliary haulage roadway serves the next adjacent working face, primarily undertaking tasks such as return air and auxiliary haulage. Under the dual-roadway layout, the surrounding rock of the auxiliary haulage roadway is affected by multiple mining events, including the disturbance from tunneling, the primary mining event of the current working face, and the secondary mining event of the adjacent next working face. Especially during the primary and secondary mining events, the roadway experiences complex stresses, resulting in severe deformation and damage to the surrounding rock, which to some extent restricts the safe and efficient mining of the working face. Currently, the support for the surrounding rock of the retained roadway often employs techniques such as anchor bolts, anchor cables, shotcrete, and grouting. These techniques are labor-intensive, pose certain safety hazards, and consume large amounts of support materials, most of which are non-recyclable. The technical and economic benefits need to be improved. Summary of the Invention

[0003] The purpose of this invention is to provide a method for strengthening the support of roadway retention in a double-roadway working face in a thin coal seam, so as to achieve rapid, timely and overall support of the surrounding rock of the roadway retention during the first mining operation, suppress the damage and deformation of the surrounding rock of the roadway retention during the mining operation of the current working face, maintain the overall integrity and stability of the roadway surrounding rock, and effectively ensure the safe use of the surrounding rock of the roadway retention during the mining operation of the next adjacent working face, i.e., the second mining operation.

[0004] The above-mentioned enhanced support method for retaining roadways in a double-roadway layout working face in thin coal seams includes the following steps:

[0005] S1, before the thin coal seam is mined, the return air roadway, transport roadway and auxiliary transport roadway are excavated in parallel on both sides of the planned area of ​​the working face. The first end of the return air roadway, transport roadway and auxiliary transport roadway is connected by the opening of the working face, and the second end is connected to each other by the withdrawal channel to form the mining working face channel, and mining equipment is arranged to form the first working face.

[0006] S2, before the first working face is mined, the auxiliary transport roadway of the first working face is used as a gob-side roadway. Reinforced support devices are arranged in advance from back to front at intervals in the gob-side roadway at a preset distance in front of the working face.

[0007] S3. As the first working face advances, the reinforced support device that enters the back of the first working face in the goaf-keeping roadway is retained, and reinforced support devices are continuously added at intervals in front of the foremost reinforced support device in step S2 until the advancing length of the first working face reaches the preset distance from the working face cut-out in step S1, and a reinforced support interval of the preset distance is formed in front of and behind the first working face.

[0008] S4. As the first working face moves forward, reinforcement support devices are continuously added at intervals in front of the foremost reinforcement support device in step S3. At the same time, reinforcement support devices that exceed the preset distance behind the first working face are withdrawn one by one, so that the reinforcement support intervals in front of and behind the first working face are kept within the preset distance, forming dynamic reinforcement support.

[0009] S5, when the first working face enters the stop line, mining stops. After mining ends, the reinforcing support devices in the reinforced support section in front of and behind the stop line are stopped. The mining equipment is withdrawn and the preset time is waited until the surrounding rock of the gob-side roadway tends to stabilize due to mining. Then, the reinforcing support devices are gradually withdrawn from the edges of the reinforced support sections on both sides of the stop line towards the stop line in both directions, thus completing the reinforcement support of the surrounding rock of the gob-side roadway during the mining of the first working face.

[0010] S6, the auxiliary transport roadway of the first working face becomes the return air roadway of the second working face, and serves as a goaf retainer. The transport roadway and auxiliary transport roadway parallel to the return air roadway are excavated. The first ends of the return air roadway, the transport roadway and the auxiliary transport roadway are connected through the opening of the working face, and the second ends are connected through the withdrawal channel to form the mining working face channel. Mining equipment is arranged to form the second working face. Before mining the second working face, reinforced support devices are arranged in advance from back to front at intervals in the goaf retainer at a predetermined distance in front of the working face opening to form a reinforced support zone.

[0011] S7. As the second working face is being mined, reinforcement support devices are continuously added at intervals in front of the foremost reinforcement support device in step S6. At the same time, the reinforcement support devices in front of the second working face are retrieved one by one, so that the reinforcement support area in front of the second working face is kept within a preset distance, forming dynamic reinforcement support.

[0012] S8, when the second working face enters the stop line, the mining stops. After the mining ends, the reinforcement support device in the reinforcement support section in front of the stop line is stopped. After the mining equipment of the second working face is withdrawn, the reinforcement support device is retrieved from front to back in sequence to complete the reinforcement support of the surrounding rock of the goaf-stayed roadway during the mining of the first and second working faces.

[0013] S9. Following steps S6-S8, support the next working face and leave the roadway until the current coal seam is mined out.

[0014] Furthermore, the return airway, as well as the transport roadway and auxiliary transport roadway, all have rectangular cross-sections and are excavated along the roof of the coal seam.

[0015] Furthermore, the spacing of the reinforced support devices is a multiple of the spacing of the roadway anchor bolts and cable supports, and the reinforced support devices do not come into contact with the roadway anchor bolts and cable supports.

[0016] Furthermore, the reinforced support device includes a crossbeam, an elastic buffer mechanism, a hydraulic cylinder, and a bottom-jointing mechanism connected sequentially from top to bottom.

[0017] Furthermore, the crossbeam is a rectangular beam, including a main beam and telescopic beams slidably installed at both ends of the main beam. The length of the crossbeam can be adjusted according to the width of the roadway to meet all roof support requirements within the roadway width range. Each reinforced support device is equipped with four sets of elastic buffer mechanisms and four hydraulic cylinders. The four sets of elastic buffer mechanisms are located at the four corners of the main beam, with both ends connected to the bottom surface of the main beam and the top of the hydraulic cylinders, respectively. The elastic buffer mechanisms can be deformed according to the actual roof pressure, with a maximum deformation of 350mm, effectively avoiding damage to the roof by the reinforced support device during the reinforced support process and maintaining the integrity and stability of the roof of the roadway.

[0018] Furthermore, the hydraulic cylinder is a double telescopic cylinder.

[0019] Furthermore, the bottom-connecting mechanism is a rectangular plate structure with a connector on the top surface for connecting to the bottom end of the hydraulic cylinder, and grooves at intervals on the bottom surface, which effectively increases the friction between the bottom-connecting mechanism and the bottom plate, while avoiding damage to the tunnel floor.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] The enhanced support method for roadway retention in thin coal seam double-roadway working faces proposed in this invention can achieve safe, efficient, and long-distance enhanced support for the surrounding rock of the roadway retention under the influence of two mining operations. The enhanced support device has the advantages of fast support speed, pressure tolerance, high strength, and recyclability. The enhanced support device can provide a uniform initial active stress for the roof of the roadway retention along the goaf. The stress can basically cover the roof within the width of the roadway. The enhanced support, together with the roadway anchor bolts and cable anchors, inhibits the development of roof delamination, optimizes the stress state of the roadway surrounding rock, and reduces the stress of the overlying strata on the roadway sidewalls. The roadway anchor bolts and cable anchors, together with the temporary enhanced support, control the deformation of the roadway surrounding rock and maintain the integrity and stability of the roadway surrounding rock. Attached Figure Description

[0022] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0023] Figure 1 This is a layout diagram of a double roadway (transport roadway and auxiliary transport roadway) in a fully mechanized longwall mining face for thin coal seams.

[0024] Figure 2 This is a layout diagram for strengthening the support of the roadway along the goaf during the mining of the 2201 working face;

[0025] Figure 3 This is a layout diagram for strengthening the support of the roadway along the goaf during the mining of the 2203 working face;

[0026] Figure 4 A front view of the reinforced support device (beam extended state);

[0027] Figure 5 A front view of the reinforced support device (beam in retracted state);

[0028] Figure 6 Side view of the reinforced support device;

[0029] Figure 7 A schematic diagram of the bottom-jointing mechanism in the reinforcement support device.

[0030] In the diagram: 1-2201 return airway; 2-2201 transport airway; 3-2201 auxiliary transport airway; 4-reinforced support device; 4.1-main beam; 4.2-telescopic beam; 4.3-elastic buffer mechanism; 4.4-hydraulic cylinder; 4.5-bottoming mechanism; 4.6-groove; 5-2203 return airway; 6-2203 transport airway; 7-2203 auxiliary transport airway; 8-coal pillar between airways. Detailed Implementation

[0031] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0032] In this embodiment, the main coal seam being mined in the Lower Permian Shanxi Formation is the No. 2 coal seam. The coal seam thickness ranges from 0.81 to 1.73 m, with an average thickness of 1.18 m. The coal seam has a simple structure, is stably developed, and does not contain interbedded gangue. The basic roof of the coal seam is medium to fine sandstone with an average thickness of 5.16 m; the immediate roof is mudstone and sandy mudstone with an average thickness of 5.86 m; the floor of the coal seam is mudstone and sandy mudstone with an average thickness of 2.95 m; and the basic bottom of the coal seam is siltstone with an average thickness of 6.46 m. The first working face in the No. 2 mining area of ​​the mine is the 2201 working face. The haulage roadways and auxiliary haulage roadways are arranged in a double-roadway configuration, with a 10m coal pillar between the roadways. The return air roadway, haulage roadway, and auxiliary haulage roadway are designed with rectangular cross-sections, with a width of 5.2m and a height of 2.6m, and are excavated along the roof of the coal seam. The auxiliary haulage roadway of the 2201 working face is a goaf-retention roadway, which will then be used as the return air roadway for the adjacent next working face, the 2203 working face. The 2201 and 2203 working faces are both 200m long, with a total advance length of approximately 2500m.

[0033] In this embodiment, the enhanced support method for retaining roadways in a working face with a double roadway layout in a thin coal seam specifically includes the following steps.

[0034] Before the thin coal seam is mined, return air roadways, transport roadways, and auxiliary transport roadways are excavated in parallel on both sides of the planned working face area. The first ends of the return air roadways, transport roadways, and auxiliary transport roadways are connected by the opening of the working face, and the second ends are connected by the withdrawal channel to form the working face channel. Mining equipment is arranged to form the 2201 working face. During the excavation, the bottom plate of the 2201 return air roadway 1, 2201 transport roadway 2, and 2201 auxiliary transport roadway 3 is hardened with concrete. After the roadway excavation is completed, the 2201 working face is ready for mining.

[0035] Before the S2,2201 working face is mined, the 2201 auxiliary transport roadway 3 is used as a goaf retainer. Reinforced support devices 4 are pre-arranged from back to front in the goaf retainer 200m in front of the working face.

[0036] The spacing of the reinforced support device 4 is twice the spacing of the roadway anchor bolts and anchor cables in the 2201 auxiliary transport roadway 3 (900mm), that is, 1800mm. The reinforced support device 4 is arranged between two adjacent rows of anchor bolts, and there are no anchor cables in the positions to ensure that the reinforced support device 4 does not interfere with the roadway anchor bolts and anchor cables during the initial support.

[0037] S3. As the 2201 working face advances, the reinforced support device 4 that enters the rear of the 2201 working face in the goaf-side roadway is retained, and reinforced support devices 4 are continuously added at intervals in front of the foremost reinforced support device 4 in step S2, until the advancing length of the 2201 working face reaches 200m from the working face cut-off point, and a 200m reinforced support interval is formed in front of and behind the 2201 working face.

[0038] S4. As the 2201 working face moves forward, reinforced support devices 4 are continuously added at intervals in front of the foremost reinforced support device 4 in step S3. At the same time, reinforced support devices 4 that are more than 200m behind the 2201 working face are withdrawn one by one, so that the reinforced support intervals in front of and behind the 2201 working face are kept within 200m, forming dynamic reinforced support.

[0039] When the S5, 2201 working face enters the stop-mining line, mining stops. After mining ends, the reinforcement support device 4 within 200m in front of and 200m behind the stop-mining line is withdrawn. The mining equipment is then withdrawn. After waiting for 2-3 months until the surrounding rock of the goaf roadway stabilizes due to mining, the reinforcement support device 4 is gradually withdrawn from the edge of the reinforcement support area on both sides of the stop-mining line towards the stop-mining line. During the withdrawal process, it is strictly forbidden to damage the roadway anchor bolts and anchor cables. This completes the reinforcement support of the surrounding rock of the goaf roadway during the mining of the 2201 working face.

[0040] S6. According to the mining sequence, mining of the 2203 working face begins. During the mining of the 2203 working face, the 2201 auxiliary transport roadway 3 is left along the goaf and continues to be used as the return air roadway of the 2203 working face. Before the mining equipment of the 2203 working face is arranged and mining has not yet begun, reinforced support devices 4 are arranged at intervals from back to front within 200m in front of the working face cutting line in the 2203 return air roadway 5, forming a reinforced support section with a length of 200m.

[0041] The spacing of the reinforced support device 4 is twice the spacing of the roadway anchor bolts and anchor cables in the 2203 return airway 5 (900mm), i.e., 1800mm. The reinforced support device 4 is arranged between two adjacent rows of anchor bolts, and there are no anchor cables in the positions to ensure that the reinforced support device 4 does not interfere with the roadway anchor bolts and anchor cables during the initial support.

[0042] S7. As the 2203 working face is being mined, reinforcement support devices 4 are continuously added at intervals in front of the foremost reinforcement support device 4 in step S6. At the same time, the reinforcement support devices 4 in front of the 2203 working face are retrieved one by one, so that the reinforcement support area in front of the 2203 working face is kept within 200m, forming dynamic reinforcement support.

[0043] When the S8 and 2203 working faces enter the stop line, mining stops. After mining ends, the reinforcement support device 4 within 200m in front of the stop line is stopped. After the mining equipment of the 2203 working face is withdrawn, the reinforcement support devices are retrieved from front to back in sequence to complete the reinforcement support of the surrounding rock of the goaf-retaining roadway during the mining of the 2201 and 2203 working faces.

[0044] S9. Following steps S6-S8, support the next working face and leave the roadway until the current coal seam is mined out.

[0045] The reinforced support device 4 includes, from top to bottom, a crossbeam, an elastic buffer mechanism 4.3, a hydraulic cylinder 4.4, and a bottom-connecting mechanism 4.5. The crossbeam is a rectangular beam, including a main beam 4.1 and telescopic beams 4.2 slidably mounted at both ends of the main beam 4.1. Each reinforced support device 4 is equipped with four sets of elastic buffer mechanisms 4.3 and four hydraulic cylinders 4.4. The four sets of elastic buffer mechanisms 4.3 are located at the four corners of the main beam 4.1, with their ends connected to the bottom surface of the main beam 4.1 and the top of the hydraulic cylinders 4.4, respectively. The hydraulic cylinders 4.4 are double telescopic cylinders. The bottom-connecting mechanism 4.5 is a rectangular plate structure with a connector on the top surface for connecting to the bottom end of the hydraulic cylinders 4.4, and grooves 4.6 spaced apart on the bottom surface.

[0046] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions 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 method for reinforcing support in a working face with a double-roadway layout in thin coal seams, characterized in that, Includes the following steps: S1, before the thin coal seam is mined, the return air roadway, transport roadway and auxiliary transport roadway are excavated in parallel on both sides of the planned area of ​​the working face. The first end of the return air roadway, transport roadway and auxiliary transport roadway is connected by the opening of the working face, and the second end is connected to each other by the withdrawal channel to form the mining working face channel, and mining equipment is arranged to form the first working face. S2, before the first working face is mined, the auxiliary transport roadway of the first working face is used as a gob-side roadway. Reinforced support devices are arranged in advance from back to front at intervals in the gob-side roadway at a preset distance in front of the working face. S3. As the first working face advances, the reinforcing support device that enters the back of the first working face in the goaf-keeping roadway is retained, and reinforcing support devices are continuously added at intervals in front of the foremost reinforcing support device in step S2 until the advancing length of the first working face reaches the preset distance in step S2 from the working face cut-out. A preset distance of reinforcing support interval is formed in front of and behind the first working face. S4. As the first working face moves forward, reinforcement support devices are continuously added at intervals in front of the foremost reinforcement support device in step S3. At the same time, reinforcement support devices that exceed the preset distance behind the first working face are withdrawn one by one, so that the reinforcement support intervals in front of and behind the first working face are kept within the preset distance, forming dynamic reinforcement support. S5, when the first working face enters the stop line, mining stops. After mining ends, the reinforcing support devices in the reinforced support section in front of and behind the stop line are stopped. The mining equipment is withdrawn and the preset time is waited until the surrounding rock of the gob-side roadway tends to stabilize due to mining. Then, the reinforcing support devices are gradually withdrawn from the edges of the reinforced support sections on both sides of the stop line towards the stop line in both directions, thus completing the reinforcement support of the surrounding rock of the gob-side roadway during the mining of the first working face. S6, the auxiliary transport roadway of the first working face becomes the return air roadway of the second working face, and serves as a goaf retainer. The transport roadway and auxiliary transport roadway parallel to the return air roadway are excavated. The first ends of the return air roadway, the transport roadway and the auxiliary transport roadway are connected through the opening of the working face, and the second ends are connected through the withdrawal channel to form the mining working face channel. Mining equipment is arranged to form the second working face. Before mining the second working face, reinforced support devices are arranged in advance from back to front at intervals in the goaf retainer at a predetermined distance in front of the working face opening to form a reinforced support zone. S7. As the second working face is being mined, reinforcement support devices are continuously added at intervals in front of the foremost reinforcement support device in step S6. At the same time, the reinforcement support devices in front of the second working face are retrieved one by one, so that the reinforcement support area in front of the second working face is kept within a preset distance, forming dynamic reinforcement support. S8, when the second working face enters the stop line, the mining stops. After the mining ends, the reinforcement support device in the reinforcement support section in front of the stop line is stopped. After the mining equipment of the second working face is withdrawn, the reinforcement support device is retrieved from front to back in sequence to complete the reinforcement support of the surrounding rock of the goaf-stayed roadway during the mining of the first and second working faces. S9. Following steps S6-S8, support the next working face and leave the roadway until the current coal seam is mined out.

2. The method for reinforced support of a working face with a double-roadway layout in thin coal seams according to claim 1, characterized in that, The return airway, as well as the transport roadway and auxiliary transport roadway, all have rectangular cross-sections and are excavated along the roof of the coal seam.

3. The method for reinforced support of working faces with double roadways in thin coal seams according to claim 1, characterized in that, The spacing of the reinforced support devices is a multiple of the spacing of the roadway anchor bolts and cable supports, and the reinforced support devices do not come into contact with the roadway anchor bolts and cable supports.

4. The method for reinforced support of a working face with a double-roadway layout in thin coal seams according to claim 1 or 3, characterized in that, The reinforced support device includes a crossbeam, an elastic buffer mechanism, a hydraulic cylinder, and a bottom-jointing mechanism connected sequentially from top to bottom.

5. The method for reinforced support of a working face with a double-roadway layout in thin coal seams according to claim 4, characterized in that, The crossbeam is a rectangular beam, including the main beam and telescopic beams that are slidably set at both ends of the main beam; Each reinforced support device is equipped with four sets of elastic buffer mechanisms and four hydraulic cylinders; Four sets of elastic buffer mechanisms are located at the four corners of the main beam, with their ends connected to the bottom surface of the main beam and the top of the hydraulic cylinder, respectively.

6. The method for reinforced support of roadway retention in a double-roadway layout working face of a thin coal seam according to claim 5, characterized in that, The hydraulic cylinder is a double telescopic cylinder.

7. The method for reinforced support of a working face with a double-roadway layout in thin coal seams according to claim 6, characterized in that, The bottom-connecting mechanism is a rectangular plate structure with a connector on the top surface for connecting to the bottom end of the hydraulic cylinder, and grooves spaced apart on the bottom surface.

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