Miner steel roadway gob-side support facility and roof cutting pressure relief gob-side entry protection method
By employing steel roadway support facilities and roof-cutting and pressure-relief blasting technology in the mining of thin and extremely thin coal seams, the problems of roadway deformation and air leakage have been solved, roadway stability and safety have been achieved, coal mining costs and labor intensity have been reduced, and the needs of efficient mining have been met.
Patent Information
- Application Number
- CN202511396668.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-09-28
- Publication Date
- 2025-11-18
AI Technical Summary
In the mining of thin and very thin coal seams, the roadways left along the goaf are prone to deformation and air leakage, which leads to increased maintenance, affects the mine's production capacity and economic benefits, and also results in high manual labor intensity.
The mine steel roadway adopts a combination of support structures including anchor bolts, anchor cables, anchor mesh, and I-beams, and combines them with roof cutting and pressure relief blasting technology to reinforce and delay support the roadway and ensure its stability.
It improves the protection of roadways, reduces coal mining costs and labor intensity, and meets the needs of efficient and safe mining.
Smart Images
Figure CN120968675A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to a construction method for a coal mining roadway support facility and a goaf protection system involving roof cutting and pressure relief. It belongs to the field of mining. Background Technology
[0002] In thin and very thin coal seam mining, gob-side roadway retention allows the roadways excavated from the previous mining face to be completely preserved and reused as the roadway for the next mining face. This technology offers rapid roadway formation, meeting the high-yield and high-efficiency requirements of mines. Currently, the unreasonable structural design and outdated construction techniques of gob-side roadway retention make the retained roadways prone to deformation and air leakage, increasing maintenance workload and significantly impacting succession work. This leads to tight mining succession schedules and severely restricts mine production capacity and economic benefits. To obtain advanced gob-side roadway protection technology, achieve better roadway protection effects, reduce coal mining costs and labor intensity, and meet the current needs of efficient and safe mining, it is necessary to design and apply new gob-side roadway protection technologies. Summary of the Invention
[0003] To address the aforementioned technical problems, this invention provides a goaf support facility for mining steel roadways and a method for goaf protection by cutting the roof and relieving pressure.
[0004] The mining steel roadway goaf support facilities are installed in the coal mining roadway, including anchor support structures installed on the roadway roof, upper side and lower side; and mining steel support structures installed on the upper side.
[0005] The aforementioned steel support structure for miners includes an I-beam installed between the roof and floor of the roadway, wherein the lower end of the I-beam is inserted into the roadway floor and positioned at the angle between the upper side and the roof of the roadway; the I-beam is inclined towards the lower side of the roadway; a crossbeam is fixed to the roadway roof via anchors and is installed along the roadway direction; the upper end of the I-beam is fixed to the crossbeam; and the waist of the I-beam is connected to the upper side of the roadway.
[0006] As mentioned above, the support facilities along the goaf of the steel mine roadway include the anchor support structure for the roadway roof and the roadway sidewall, which includes a combined support structure composed of anchor bolts, anchor cables, anchor mesh, and steel strip beams. Among them, three anchor cables are arranged in each row on the roof of the roadway, with a spacing of 1600mm and a row spacing of 1400mm; and seven anchor rods are arranged with a spacing of 800mm and a row spacing of 600mm; the anchor cables are arranged in the middle of the two rows of anchor rods; the anchor cables set on both sides of the roof of the roadway are at 15° to the vertical direction, and the anchor cables located on the central axis of the roadway are perpendicular to the roof of the roadway. Four anchor bolts are installed on the upper and lower sides of the roadway respectively; the anchor bolts near the top of the roadway are inclined upwards and form a 20° angle with the horizontal plane, while the anchor bolts near the bottom of the roadway are inclined downwards and form a 20° angle with the horizontal plane; all are spaced 800mm apart and arranged in rows of 800mm.
[0007] As described above in the goaf support facility for a miner's steel roadway, the connection of the web of the I-beam to the upper side of the roadway specifically involves driving anchors into the upper side of the roadway perpendicular to its direction and connecting them to the web of the I-beam; specifically: A buffer retaining column is installed to reduce the impact of gangue on the waist of the I-beam in the goaf; the lower end of the buffer retaining column is fixed to the upper side of the roadway by an anchor, and the upper end extends from above the upper side of the roadway to the gangue outlet, and is located between the gangue outlet and the I-beam; the upper end of the buffer retaining column is connected to the middle section of the I-beam.
[0008] As described above, in the goaf support facility of the mining steel roadway, the buffer rock-blocking column includes a fixed end at the lower end and a rock-blocking end at the upper end, with the fixed end and the rock-blocking end forming an angle greater than 145°, so that the rock-blocking end moves closer to the middle section of the I-beam; a reinforcing rib is provided in the angle. The upper end of the buffer retaining column is connected to the middle section of the I-beam by a clamp; the upper end of the buffer retaining column is equipped with an anti-slip clip to fix the clamp; The roadway has a first rock groove, adapted to the width of the buffer rock retaining column, for installing the buffer rock retaining column; and an anchor is driven into the roof in the first rock groove; the anchor passes through the buffer rock retaining column and is anchored to it.
[0009] As described above, in the goaf support facility for a steel mine roadway, the crossbeam is a channel steel with a downward slot and several holes are provided on the channel steel; a second rock groove adapted to the width of the channel steel is provided on the roadway roof for installing the channel steel, and anchors are driven into the roof in the second rock groove; the anchors are fixed to the channel steel through the holes. The top of the I-beam is inserted into the slot of the channel steel; The I-beams are inclined toward the lower side of the roadway, specifically at the angle between the upper side of the roadway and the roof, where they are misaligned with the second rock groove, causing the I-beams to incline 5°-10° toward the lower side of the roadway.
[0010] As mentioned above, the support facilities along the goaf of the steel roadway in the mine are provided, in which the I-beams are connected and fixed to each other by transverse connecting rods; A rock-blocking facility, including anchor mesh, scrap conveyor belts, and wire mesh, is installed on the goaf side of the I-beam.
[0011] The method for cutting off the roof and relieving pressure along the goaf provided by this invention includes: Before the coal mining face advances, the roadway is reinforced and supported on the basis of the anchor support structure of the roadway roof, upper sidewall, and lower sidewall. Deep-hole pre-splitting, roof cutting, and pressure relief blasting are carried out at a location more than 30m ahead of the coal mining face. After the coal mining face is advanced, the above-mentioned steel support structure for the upper side of the roadway is constructed. Based on the reinforced support structure, delayed reinforcement support is carried out on the roadway.
[0012] In the above-described method of roof cutting and pressure relief along the goaf, the roadway reinforcement and support specifically includes: This includes strengthening the support of the roadway roof. The first anchor cable is installed 1.5m away from the upper side of the roadway roof, and the second anchor cable is installed 1.8m away from the first anchor cable. Point anchors are used for support with a spacing of 1800mm and a row spacing of 1800mm. Including roadway lower side reinforcement support: Anchor cables with wire mesh and steel strip beams are used as a combination reinforcement support for the lower side of the roadway, with an anchor cable spacing of 800mm and a row spacing of 800mm; This includes the reinforcement and support of the roadway upper side: a combination of anchor cables, wire mesh, and steel strip beams is used for reinforcement and support, with an anchor cable spacing of 800mm and a row spacing of 800mm.
[0013] In the above-described method of roof cutting and pressure relief along the goaf, the deep-hole pre-splitting roof cutting and pressure relief blasting specifically refers to: At the shoulder joint where the roadway meets the roadway roof, a row of blasting holes is constructed with a spacing of 500mm and a depth of 7m. The blasting holes are inclined to the opposite side of the roadway and form an 85° angle with the horizontal plane. A shaped charge tube is installed in the blasting hole, and the cut direction of the shaped charge tube is aligned with the pre-splitting line parallel to the roadway direction. The blasting explosive is emulsion explosive, with a dosage of 2400g per blast hole. Millisecond delay electric detonators are used. The blasting progress is consistent with the advance of the coal mining face. The blasting is carried out in series with one initiation. The maximum number of blasting holes does not exceed 4.
[0014] In the above-described method of roof cutting and pressure relief along the goaf, the delayed reinforcement support of the roadway specifically refers to: In sections more than 100m behind the coal mining face, delayed reinforcement support is carried out on the roadway. include: The construction unit uses a single hydraulic prop with wooden cantilever planks for support. The spacing between the single hydraulic props is 1000mm and the row spacing is 1500mm. The props are perpendicular to the top and bottom plates. For newly exposed roof slabs and for failed supports in existing supports, delayed reinforcement should be provided.
[0015] This invention enables the goaf protection technology to achieve better goaf protection effect, while reducing coal mining costs and labor intensity, thus meeting the current needs for efficient and safe mining in mines. Attached Figure Description
[0016] Figure 1 This is a schematic diagram of the construction of each support structure of the roadway before the coal mining face advances according to the present invention; Figure 2 This is a schematic diagram of the construction of each support structure of the roadway after the coal mining face is advanced according to the present invention; Figure 3 This invention relates to the support arrangement of the upper side of the roadway during the advance of the coal mining face.
[0017] Figure 4 This is a top view showing the layout of the roadway and the coal mining face during the advance of the coal mining face in this invention.
[0018] Figure 5 This is the mounting structure for the I-beam of the present invention; Figure 6 This is a schematic diagram of the connection structure between the buffer rock-blocking column and the I-beam of the present invention.
[0019] Among them: 1. Coal mining face; 2. Goaf; 3. Miner's steel support structure; 4. Anchor bolt; 5. Channel steel; 6. I-beam; 7. Rockfill retaining facility; 8. Hoop; 9. Dense point pillar; 10. Hydraulic support; 11. Second rock trench; 12. Roadway roof; 13. Roadway floor; 14. Roadway upper side; 15. Roadway lower side; 16. Anchor cable; 17. Buffer rockfill retaining pillar; 18. Reinforcing rib plate. Detailed Implementation
[0020] Example 1: The environmental conditions under which this invention is used are as follows: Coal mining face 1 is a longwall mining type. The average dip length of coal mining face 1 is approximately 100m. The coal seam dip angle of coal mining face 1 is 15°–21°, belonging to a gently dipping coal seam, and the coal seam thickness is 1.76m–2.18m. The mining height is 2.01m to 2.23m, and the coal seam contains 1 to 2 layers of interbedded rock. The coal seam is stable.
[0021] The false roof of the coal seam is silty mudstone, approximately 0.10-0.40m thick. The immediate roof consists of alternating layers of dark gray sandy mudstone and silty mudstone, approximately 5.0m thick. The main roof is gray fine- to medium-grained sandstone, containing numerous black minerals and coal dust. Due to tectonic forces, the rock integrity is poor, with well-developed joints and fissures, approximately 15m thick. The main floor is gray siltstone and light gray to grayish-white fine- to medium-grained sandstone, with well-developed horizontal bedding and muscovite fragments between the bedding planes, approximately 47.0m thick. The immediate floor consists of black carbonaceous mudstone, gray mudstone, and siltstone, approximately 0.6m thick.
[0022] The tunnel is constructed by tunneling along the coal seam. It has an irregular cross-section, with a width of 4500mm, a lower sidewall height of 15 of 2700mm, and an upper sidewall height of 14 of 3800mm.
[0023] Example 2: The miner's steel roadway goaf support facility is installed in the coal mining roadway, including the anchor support structure installed on the roadway roof 12, the roadway upper side 14, and the roadway lower side 15; and the miner's steel support structure 3 installed on the roadway upper side 14.
[0024] (I) Anchor support structure.
[0025] Controlling the subsidence and rotation of the roadway roof 12 is crucial for ensuring the stability of the surrounding rock in gob-side retaining roadways. Unlike ordinary roadways, gob-side retaining roadways require a longer service life. During roadway excavation, the surrounding rock integrity is lower than in typical roadways due to the mining of the upper coal seam, and the roadway experiences the effects of two mining operations, resulting in more intense mine pressure manifestations and shorter pressure cycles. If the roof support strength is insufficient, roof delamination and displacement will occur, exacerbating the damage and deformation of the solid coal seam and the roadway side support. When designing the support for the roadway roof 12, the synergistic support effect of the roadway roof 12, the roadway side support, and the solid coal seam should be considered. Therefore, in this example, the anchor support structure of the roadway roof 12, the upper sidewall 14, and the lower sidewall 15 is used to anchor the shallow rock strata of the roof into a whole by installing anchors, and then use anchor cables 16 to connect the shallow rock strata of the roof with the deep rock strata to form a larger common bearing body, so as to limit the rotation and subsidence of the roadway roof.
[0026] The anchorage support structure includes a combined support structure consisting of anchor bolts 4, anchor cables 16, anchor mesh, and steel strip beams.
[0027] Specifically, three anchor cables 16 with a diameter of 17.8 mm and a length of 6200 mm are arranged in each row on the roof slab 12 of the roadway, with a spacing of 1600 mm and a row spacing of 1400 mm; and seven resin anchor rods 4 with a diameter of 20 mm and a length of 2000 mm are arranged with a spacing of 800 mm and a row spacing of 600 mm; the anchor cables 16 are arranged in the middle of the two rows of anchor rods 4; the anchor cables 16 set on both sides of the roof slab 12 are driven at a 15° angle to the vertical direction, and the anchor cables 16 located on the central axis of the roadway are driven perpendicular to the roof slab 12 of the roadway. Four resin anchor bolts 4 with a diameter of 18 mm and a length of 1800 mm are installed on the upper side 14 and lower side 15 of the tunnel respectively; the anchor bolts 4 near the tunnel roof 12 are inclined upward and driven at a 20° angle to the horizontal direction, while the resin anchor bolts 4 near the tunnel floor 13 are inclined downward and driven at a 20° angle to the horizontal direction; the spacing between them is 800 mm and the row spacing is 800 mm.
[0028] (II) Steel support structure for miners 3.
[0029] Before the miners install steel support, the workers need to set up an operating platform at the construction site, using a combination of scaffolding and fasteners.
[0030] The system includes an I-beam 6 positioned between the tunnel roof 12 and the tunnel floor 13, with the lower end of the I-beam inserted into the tunnel floor 13 and positioned at the angle between the tunnel upper side 14 and the tunnel roof 12; the I-beam is inclined toward the tunnel lower side 15; a crossbeam is fixed to the tunnel roof 12 by anchors and is positioned along the tunnel direction; the upper end of the I-beam is fixed to the crossbeam to increase the load-bearing area of the I-beam 6.
[0031] The waist of the I-beam 6 is connected to the upper side 14 of the roadway. Specifically, anchors are driven into the upper side 14 of the roadway and connected to the waist of the I-beam. A buffer retaining column 17 is installed to reduce the impact of gangue from the goaf 2 on the waist of the I-beam 6. The lower end of the buffer retaining column 17 is fixed to the upper side 14 of the roadway by anchors, and the upper end extends from above the upper side 14 to the gangue outlet, positioned between the gangue outlet and the I-beam 6; the upper end of the buffer retaining column 17 is connected to the middle section of the I-beam. The buffer retaining column 17 is also made of I-beam 6, with a height of 1.2 meters, and is bent along the flange direction to form a fixed end at the lower end and a retaining end at the upper end. The fixed end and the retaining end form an angle greater than 145°, so that the retaining end is closer to the middle section of the I-beam; a reinforcing rib plate 18 is installed in the angle. The upper end of the buffer rock-retaining column 17 is connected to the middle section (i.e., the waist) of the I-beam 6 by clamp 8; the upper end of the buffer rock-retaining column 17 is provided with an anti-slip slot for fixing the clamp 8. The upper sidewall 14 of the roadway is longitudinally provided with a first rock groove adapted to the width of the buffer rock-retaining column 17 for installation; and anchors are driven into the roof in the first rock groove; anchor holes are constructed at a position 1m away from the floor of the upper sidewall 14 of the roadway using a pneumatic hammer, and anchors are driven in, the anchors pass through the buffer rock-retaining column 17 and are anchored to it, specifically by using anchor cables 16 (3m long, φ21.6mm) to support and fix the buffer rock-retaining column 17. The buffer retaining pillar 17 extends upwards from the edge of the waste rock outlet on the upper side of the roadway 14, reaching the waist of the I-beam 6, and then connects with it. This effectively reduces the pressure on the waist of the I-beam 6 caused by the sliding of waste rock from the goaf 2. The middle of the I-beam bears the greatest pressure, and without support, it is prone to bending towards the roadway side. Therefore, the buffer retaining pillar 17 is fixed with anchors, and further connected to the middle section of the I-beam 6 by clamps 8; this distributes some of the pressure from the waist of the I-beam to the buffer retaining pillar 17, which is then secured by anchors. Simultaneously, some of the rolling waste rock behind it directly impacts the buffer retaining pillar 17, further relieving pressure on the I-beam. This design allows the pressure in the middle of the I-beam to be indirectly borne by the anchorage on the upper slab 14 of the tunnel. Even when there is a distance between the surface of the upper slab 14 and the I-beam, the anchorage does not need to extend from the rock mass to connect with the I-beam 6, which helps protect the anchorage and prevents it from being exposed and struck by rock fragments. The anchorage has strong tensile strength but weak shear strength. Furthermore, the installation angle of the I-beam 6 is not perpendicular to the anchorage, and considering the deformation direction of the I-beam 6, the anchorage directly mounted on the I-beam will be subjected to shear force.
[0032] When the buffer rock-blocking column 17 is subjected to force and bends and deforms in the direction of the coal mining roadway, the buffer rock-blocking column 17 will move closer to the I-beam. At this time, further tightening the screws on the clamp 8 can make the buffer rock-blocking column 17 continue to tighten the I-beam 6.
[0033] The crossbeam is a channel steel 5, with the channel steel 5 slotted downwards. An eyelet is provided at each end of the channel steel 5, with each eyelet 200mm from the end. A second rock groove 11, adapted to the width of the channel steel 5, is provided on the tunnel roof 12 for installing the channel steel 5. Anchor holes were drilled into the top slab within the second rock trench 11 for installing anchors. The anchor bolt holes 4 were constructed using a pneumatic anchor bolt drilling rig. Immediately after the holes were drilled, the anchor bolts 4 were inserted into the holes, with two strips of anchoring agent inserted into each anchor bolt 4 to ensure the stable installation of the channel steel 5. The anchors were fixed to the channel steel 5 through the holes; the anchors were supported using extended anchor bolts 4 (1.8m long, φ20mm).
[0034] After the channel steel 5 is fixed, the workers will move the I-beams to the roadway protection location and provide support. The bottom plate of the I-beam 6 must lie flat on the solid ground, close to the upper sidewall 14 of the roadway. The top of the I-beam should be inserted into the slot of the channel steel 5 and close to the crossbeam. The spacing between the I-beams 6 should be ≤500mm.
[0035] The I-beam is inclined toward the lower side 15 of the roadway. Specifically, at the angle between the upper side 14 of the roadway and the roof 12 of the roadway, it is misaligned with the second rock trough 11, causing the I-beam to be inclined toward the lower side 15 of the roadway by 5°-10°.
[0036] For each I-beam 6, anti-tipping measures should be taken, and the I-beams should be connected and fixed together with transverse connecting rods; another example is that the I-beams 6 are tied together with wire ropes to ensure that they are connected end to end, thereby enhancing the overall stability of the I-beam 6 support.
[0037] A rock-blocking facility 7, consisting of anchor mesh, scrap conveyor belts, and No. 14 wire mesh, is installed on both sides of the goaf area 2 of the H-beam 6. The support sequence for the rock-blocking facility 7 is as follows: first, lay the anchor mesh close to the H-beam, then lay the scrap conveyor belt inside the anchor mesh to ensure effective rock blocking and prevent rock spillage accidents that could injure workers in goaf area 2. Every 10 meters along the tail roadway of the advancing coal face 1, a "No Entry" warning sign must be installed to ensure the safety of workers.
[0038] Example 3: Methods for cutting the roof to relieve pressure and protecting the roadway along the goaf.
[0039] (i) Before advancing the coal mining face 1, reinforce the roadway with additional support on the basis of the anchor support structure of the completed roadway roof 12, roadway upper sidewall 14, and roadway lower sidewall 15.
[0040] 1. Roof reinforcement support for roadway 12. The first anchor cable 16 is installed 141.5m ahead of the coal face 1, at a distance of φ21.6mm and L7m from the upper sidewall of roadway 12. A second anchor cable 16 is installed 1.8m from the first anchor cable 16, using point anchoring for support, with a spacing of 1800mm and a row spacing of 1800mm. The anchor cable 16 uses 300mm×300mm steel block trays and is tensioned with locking devices. This method enhances the stability of the roof and prevents roof collapse during mining.
[0041] 2. Reinforcement support for the lower sidewall 15 of the roadway. Anchor cables 16 with wire mesh and "W"-shaped steel beams are used as a combined reinforcement support for the lower sidewall 15. The anchor cables 16 are 3180mm long and 21.6mm in diameter, with a spacing of 800mm between each cable and the row spacing of 800mm. The upper anchor bolts 4 of the lower sidewall 15 are no more than 150mm from the shoulder socket. The anchor mesh of the lower sidewall 15 must be connected to the anchor mesh of the roadway roof 12 to form an integrated support structure, effectively controlling the deformation of the surrounding rock in the lower sidewall.
[0042] 3. Reinforcement support for the upper sidewall 14 of the roadway. A combination of anchor cables 16, wire mesh, and "W"-shaped steel beams is used for reinforcement support. The anchor cables 16 are 3180mm long and 21.6mm in diameter, with a spacing of 800mm between each cable and each row. The upper anchor bolt 4 is located no more than 150mm from the shoulder socket. The anchor mesh of the upper sidewall 14 is connected to the anchor mesh of the roadway roof 12, improving the support strength of the upper sidewall 14 and ensuring the stability of the high sidewall during mining.
[0043] (ii) The blasting for roof cutting and pressure relief must be carried out 30m ahead of the coal face. This is because the pressure step distance of the coal face in the first cycle is about 20m. The roof will start to collapse within this range, and the gangue in the goaf can fill the area behind it, so the overall pressure on the wall is relatively small.
[0044] Deep-hole pre-splitting and roof-cutting pressure relief blasting is carried out at a depth of over 130m ahead of the coal face. Specifically, a row of blasting holes is constructed at the shoulder joint where the upper side 14 and the roof 12 of the roadway meet. The holes are arranged in a line with a spacing of 500mm and a depth of 7m. The holes are inclined at an 85° angle to the horizontal plane opposite to the roadway. This arrangement ensures the blasting effect, effectively cutting off the stress transmission of the roof and achieving the purpose of roof cutting and pressure relief. A shaped charge tube is installed inside the blasting hole, with the cut direction aligned with the pre-splitting line parallel to the roadway direction. The shaped charge tube is made of PVC pipe with a diameter of 40mm and a length of 2000mm. The diameter of the deep-hole pre-splitting blasting holes is determined based on the diameter of the emulsion explosive used in the mine (Φ32mm×330mm / roll), ensuring concentrated energy release of the explosive and improving the blasting effect. The shaped charge tube is loaded with explosives aligned with the pre-splitting line. The blasting explosives used are Class III coal mine permissible emulsion explosives, with a dosage of 2400g per borehole (adjustable on-site according to lithology), and a maximum charge of no more than 19.2kg. Yellow mud is used to seal the boreholes, with a total sealing length of no less than 1000mm to ensure the safety and stability of the blasting. Millisecond delay electric detonators are used, and all detonators are of the same type. The blasting progress is consistent with the advance of the coal face, using a series detonation method. The maximum number of blasting holes does not exceed 4, and the blasting length along the roadway is approximately 2m. Blasting parameters are strictly controlled to avoid excessive damage to the roadway and surrounding rock.
[0045] During the advancement of the coal mining face 1, the coal mining face 1 has hydraulic supports 10 to support the roof. At the same time, dense point pillars 9 should be installed in advance at the coal mining face 1 during the advancement of the coal mining face 1 to support the lower exit of the coal mining face 1.
[0046] (III) After the coal mining face 1 advances, the miners' steel support structure 3 is constructed on the upper side 14 of the construction roadway. The construction method is described in Part II of Example 2.
[0047] IV. Based on the reinforced support structure, delayed reinforcement support will be implemented for the roadway. Specifically, the delayed support area will be located more than 100m behind the coal face 1. Delayed reinforcement support will be implemented in this area because after the coal face 1 is mined, the concentrated roof pressure will act on the remaining roadway area, requiring reinforcement support. This includes: 1. Using individual hydraulic props with wooden planks for support. The spacing between individual hydraulic props is 1000mm and the row spacing is 1500mm. The props are perpendicular to the roof and floor, providing additional support. 2. After mining, each shift will reinforce newly exposed roof and the failed original roadway support. Reinforcement will use anchor cables 16 with steel strips and wire mesh, with a row spacing of 900×900mm. The anchor cables 16 have a diameter of 21.6mm and a length of 5.18m. Timely repair and reinforcement of roadway support will ensure the safe use of the roadway.
[0048] Example 4: Pressure monitoring along the goaf protection of coal mining roadways where this invention has been implemented: Surface displacement and deformation of roadways are among the main forms of deformation and failure of the surrounding rock, making effective monitoring crucial. When roof delamination and roadway deformation exceed a certain range, it indicates that the roof is in an unstable state. If support measures are not taken in time, serious roof falls and other catastrophic accidents are highly likely to occur. Because the failure of roofs supported by anchor mesh in coal roadways is highly concealed, roadway instability often occurs without obvious warning signs, and the failure is sudden, with large-scale collapses that can cause extremely serious hazards. Therefore, delamination monitoring and inspection are conducted on roadways supported by anchor bolts (4 bolts).
[0049] After reinforcement and support, roof delamination monitoring devices and roadway deformation observation points are installed every 50m on the roadway roof to monitor the roof condition in real time. Observations are conducted weekly, and detailed records are kept. If significant delamination or deformation occurs on the machine roadway roof, immediate measures must be taken to address the issue.
[0050] Observation Item: Roadway surface displacement monitoring. Measurement Point Installation and Observation Method: In roadways where this invention has been implemented, representative anchor bolt 4-plate locations are selected every 8 meters to install measurement points, which are then numbered sequentially. The installation method involves determining a point on the anchor bolt 4-plate, and then embedding wooden stakes vertically below it and horizontally on both sides. Bent measuring nails are installed at the ends of the wooden stakes on the roof and upper sides, while flat-headed measuring nails are installed at the ends of the wooden stakes on the floor and lower sides. The observation method involves using a measuring tape to determine the initial values, and then measuring every other day to determine the convergence of the roof and floor plates and the convergence of the two sides, until the observation point is no longer accessible in the tail section. A final observation is conducted after ventilation is restored, and simultaneously, a measuring tape is used to measure the distance from the monitoring section to the coal face at coal seam 1.
[0051] Preliminary conclusions from the observation of surrounding rock approach: The approach measurements of the two sides at the three measuring points were 150 mm, 210 mm, and 250 mm, respectively, showing significant differences. This is largely related to the specific locations of the measuring points on both sides and the characteristics of the surrounding rock. The approach measurements of the roof and floor at the three measuring points were 170 mm, 180 mm, and 120 mm, respectively, showing a relatively consistent trend and indicating that the roof and floor approach measurements were relatively stable. The roof and floor approach measurements include not only roof subsidence but also floor heave. From the field observation, the anchor bolts 4 and anchor mesh were relatively intact, indicating a good effect on goaf protection. Observation results: During the roadway reuse period, through strengthened support, the failure rate of anchor bolts 4 and anchor cables 16 was less than 0.5%, the goaf protection subsidence was controlled within 300 mm, and the roof separation monitoring at the roadway 12 showed little change, achieving the expected goaf protection effect and providing reliable roadway conditions for subsequent coal mining.
[0052] Surrounding Rock Observation Record Form: The above is an exemplary description of the present invention and does not represent the scope of protection of the present invention.
Claims
1. Mining steel roadway goaf support facilities, installed in coal mining roadways, including anchor support structures installed on the roadway roof, upper sidewall, and lower sidewall; and mining steel support structures installed on the upper sidewall. Its features are, The aforementioned steel support structure for miners includes an I-beam installed between the roof and floor of the roadway, wherein the lower end of the I-beam is inserted into the roadway floor and positioned at the angle between the upper side and the roof of the roadway; the I-beam is inclined towards the lower side of the roadway; a crossbeam is fixed to the roadway roof via anchors and is installed along the roadway direction; the upper end of the I-beam is fixed to the crossbeam; and the waist of the I-beam is connected to the upper side of the roadway.
2. The support facility along the goaf of a miner's steel roadway as described in claim 1, characterized in that, The anchorage support structure for the roadway roof and roadway sidewall includes a combined support structure consisting of anchor bolts, anchor cables, anchor mesh, and steel strip beams; Among them, three anchor cables are arranged in each row on the roof of the roadway, with a spacing of 1600mm and a row spacing of 1400mm; and seven anchor rods are arranged with a spacing of 800mm and a row spacing of 600mm; the anchor cables are arranged in the middle of the two rows of anchor rods; the anchor cables set on both sides of the roof of the roadway are at 15° to the vertical direction, and the anchor cables located on the central axis of the roadway are perpendicular to the roof of the roadway. Four anchor bolts are installed on the upper and lower sides of the roadway respectively; the anchor bolts near the top of the roadway are inclined upwards and form a 20° angle with the horizontal plane, while the anchor bolts near the bottom of the roadway are inclined downwards and form a 20° angle with the horizontal plane; all are spaced 800mm apart and arranged in rows of 800mm.
3. The support facility along the goaf in a miner's steel roadway as described in claim 2, characterized in that, The aforementioned method of connecting the web of the I-beam to the upper side of the roadway specifically involves driving anchors into the upper side of the roadway perpendicular to its direction and connecting them to the web of the I-beam; specifically: A buffer retaining column is installed to reduce the impact of gangue on the waist of the I-beam in the goaf; the lower end of the buffer retaining column is fixed to the upper side of the roadway by an anchor, and the upper end extends from above the upper side of the roadway to the gangue outlet, and is located between the gangue outlet and the I-beam; the upper end of the buffer retaining column is connected to the middle section of the I-beam.
4. The support facility along the goaf in a miner's steel roadway as described in claim 3, characterized in that, The buffer rock-blocking column includes a fixed end at the lower end and a rock-blocking end at the upper end. The fixed end and the rock-blocking end form an angle greater than 145°, so that the rock-blocking end moves closer to the middle section of the I-beam; a reinforcing rib is provided in the angle. The upper end of the buffer retaining column is connected to the middle section of the I-beam by a clamp; the upper end of the buffer retaining column is equipped with an anti-slip clip to fix the clamp; The roadway has a first rock groove, adapted to the width of the buffer rock retaining column, for installing the buffer rock retaining column; and an anchor is driven into the roof in the first rock groove; the anchor passes through the buffer rock retaining column and is anchored to it.
5. The support facility along the goaf in a miner's steel roadway as described in claim 1, characterized in that, The crossbeam is a channel steel with a downward slot and several holes. A second rock groove adapted to the width of the channel steel is set in the roof of the roadway for installing the channel steel, and anchors are driven into the roof in the second rock groove. The anchors are fixed to the channel steel through the holes. The top of the I-beam is inserted into the slot of the channel steel; The I-beams are inclined toward the lower side of the roadway, specifically at the angle between the upper side of the roadway and the roof, where they are misaligned with the second rock groove, causing the I-beams to incline 5°-10° toward the lower side of the roadway.
6. The support facility along the goaf in a miner's steel roadway as described in claim 1, characterized in that, The I-beams are connected and fixed together by transverse connecting rods; A rock-blocking facility, including anchor mesh, scrap conveyor belts, and wire mesh, is installed on the goaf side of the I-beam.
7. A method for roof cutting, pressure relief, and goaf protection along the roadway, characterized in that: include: Before the coal mining face advances, the roadway is reinforced and supported on the basis of the anchor support structure of the roadway roof, upper sidewall and lower sidewall as described in claim 1. Deep-hole pre-splitting, roof cutting, and pressure relief blasting are carried out at a location more than 30m ahead of the coal mining face. After the coal mining face is advanced, the miner's steel support structure for the upper side of the roadway as described in claim 1 is constructed. Based on the reinforced support structure, delayed reinforcement support is carried out on the roadway.
8. The method for cutting the roof and relieving pressure along the goaf as described in claim 7, characterized in that, The aforementioned roadway reinforcement and support specifically includes: This includes strengthening the support of the roadway roof. The first anchor cable is installed 1.5m away from the upper side of the roadway roof, and the second anchor cable is installed 1.8m away from the first anchor cable. Point anchors are used for support with a spacing of 1800mm and a row spacing of 1800mm. Including roadway lower side reinforcement support: Anchor cables with wire mesh and steel strip beams are used as a combination reinforcement support for the lower side of the roadway, with an anchor cable spacing of 800mm and a row spacing of 800mm; This includes the reinforcement and support of the roadway upper side: a combination of anchor cables, wire mesh, and steel strip beams is used for reinforcement and support, with an anchor cable spacing of 800mm and a row spacing of 800mm.
9. The method for cutting the roof and relieving pressure along the goaf as described in claim 7, characterized in that, The deep-hole pre-fracture cutting and pressure relief blasting specifically refers to: At the shoulder joint where the roadway meets the roadway roof, a row of blasting holes is constructed with a spacing of 500mm and a depth of 7m. The blasting holes are inclined to the opposite side of the roadway and form an 85° angle with the horizontal plane. A shaped charge tube is installed in the blasting hole, and the cut direction of the shaped charge tube is aligned with the pre-splitting line parallel to the roadway direction. The blasting explosive is emulsion explosive, with a dosage of 2400g per blast hole. Millisecond delay electric detonators are used. The blasting progress is consistent with the advance of the coal mining face. The blasting is carried out in series with one initiation. The maximum number of blasting holes does not exceed 4.
10. The method for cutting the roof and relieving pressure along the goaf as described in claim 7, characterized in that, The aforementioned delayed reinforcement support for the roadway specifically includes: In sections more than 100m behind the coal mining face, delayed reinforcement support is carried out on the roadway. include: The construction unit uses a single hydraulic prop with wooden cantilever planks for support. The spacing between the single hydraulic props is 1000mm and the row spacing is 1500mm. The props are perpendicular to the top and bottom plates. For newly exposed roof slabs and for failed supports in existing supports, delayed reinforcement should be provided.