A rapid construction method for cutting holes in large-angle coal seams

Abstract

The present invention relates to the technical field of coal mining, and specifically to a method for rapid construction of eyelet cutting in a steeply inclined coal seam, including one-time excavation and secondary expansion and brushing. The high-level tunnel of the working face is first located in the low-level tunnel. One-time excavation includes constructing an eyelet cutting guide tunnel from the high-level tunnel from top to bottom until the low-level tunnel is in place, and then constructing the eyelet cutting guide tunnel from the low-level tunnel from bottom to top until it is through; and secondary expansion and brushing is to expand and brush along the side of the eyelet cutting guide tunnel to the full width of the eyelet. This construction method organizes the eyelet cutting construction of the steeply inclined coal seam matching face using two head-on alternating excavations, batch construction, and overall expansion and brushing, and provides support technology and safety measures, creatively proposes a steeply inclined conveyor to transport gangue from bottom to top and relay transportation technology; a buffering technology for steeply inclined gangue transportation from top to bottom, which can effectively shorten the construction period of eyelet cutting in steeply inclined coal seams, and the construction process is safe and reliable.

Description

Technical Field

[0001] This invention relates to the field of coal mining technology, specifically to a rapid construction method for face cutting in steeply inclined coal seams. Background Technology

[0002] Steeply inclined coal seams are one of the main types of coal resources in my country, and mining of this type of coal seam is involved in various regions. The central and western regions have abundant reserves, high output, and a high degree of production concentration. Compared with the construction of near-horizontal and gently inclined coal seams, the construction of steeply inclined coal seams is particularly difficult. This is because the vertical drop in steeply inclined coal seams is very high, requiring direct upward excavation along the dip direction. This necessitates addressing issues such as single-hole ventilation, reducing the labor intensity of workers, preventing large amounts of coal from falling from heights during excavation and roadway widening, causing injuries from flying debris, spalling, and other significant safety risks. This results in a long construction period; typically, a 150m long seam takes 2.5-3 months to complete. However, when the seam length is even longer, the existing steeply inclined coal seam construction methods result in an excessively long construction period, delaying face preparation and affecting long-term continuity. Summary of the Invention

[0003] To address the technical problem that using existing methods for cutting long faces in steeply inclined coal seams can delay face preparation time and affect long-term continuity, this invention provides a rapid construction method for face preparation cuts in steeply inclined coal seams. This method employs alternating tunneling to achieve cross-cutting, phased construction followed by widening and sizing, and advance material preparation for centralized drying, effectively shortening the construction cycle for cutting long faces in steeply inclined coal seams.

[0004] A rapid construction method for face cutting in steeply inclined coal seams includes a primary excavation and a secondary widening. The high-level roadway of the working face first reaches the low-level roadway. The primary excavation includes constructing a guide tunnel from the high-level roadway downwards until the low-level roadway is in place, and then constructing a guide tunnel from the low-level roadway upwards until it is connected. The secondary widening involves widening the tunnel to the full width of the cut.

[0005] Furthermore, high-level tunnels are track tunnels, and low-level tunnels are transport tunnels.

[0006] Furthermore, the cut-in guide tunnel was constructed with a width of 3.6m and a height of 2.5m, resulting in a total width of 7.6m for the cut-in.

[0007] Furthermore, a single tunneling operation specifically includes:

[0008] (1) Construction proceeds from top to bottom, tunneling along the roof of the coal seam, using laser orientation, blasting to drop coal, manual loading, using a scraper conveyor to lift and transport it to the track roadway, and then using a belt conveyor in the track roadway to transport the coal; using a forward-exploring beam for temporary support;

[0009] (2) Construction proceeds from bottom to top. Coal is blasted at the face and falls through plastic chutes to the outlet below the cut. It is then discharged by the tunneling machine to the rear belt conveyor and then transferred to the scraper conveyor in the transport roadway. After being crushed by the crusher, the coal and gangue are buffered in the shuttle car. The shuttle car unloads the coal and gangue to the second belt according to the belt operation. Temporary support is provided by the front probe beam.

[0010] Further expansion and digging include expansion and digging along the east side of the cut-out guide tunnel, blasting coal, manual coal shoveling, plastic chutes for self-flowing, and coal transportation using transport roadways, tunneling machines, and belt conveyors.

[0011] Furthermore, the support method for a single tunneling operation is as follows: permanent support is provided using anchored mesh; the roof support material is 600# high-strength threaded steel resin anchor bolts used in conjunction with W-shaped steel strips, with an anchor bolt spacing of 800×800mm; the sidewalls are supported by φ335# high-strength threaded steel resin anchor bolts used in conjunction with W-shaped protective plates, with anchor bolt spacings of 800×800mm and 800×1600mm respectively; 6300mm anchor cable reinforcement support is provided, with an anchor cable spacing of 1600×1600mm, and the anchor cable reinforcement support is no more than 2m from the face; two single hydraulic props are installed in the cut-out in conjunction with U-shaped steel top beams as passive support, with a spacing of 1500×1600mm.

[0012] Furthermore, the support method for the second expansion and sizing is as follows: the cut-and-expand roadway adopts permanent anchor belt mesh support, the roof support material is 600# high-strength threaded steel resin anchor bolts with six-hole W steel strips, and the anchor bolt spacing is 800×800mm; the east side uses 335# high-strength threaded steel anchor bolts with W-plates, the anchor bolt spacing is 800×800mm, and the side anchor bolts trailing behind the face does not exceed 1100mm; φ22mm×6300mm anchor cables reinforce the support, the anchor cable spacing is 1600mm×1600mm; the maximum distance between the reinforced support anchor cables and the face does not exceed 5m; the steel strips are staggered and overlapped by no less than 200mm.

[0013] Furthermore, the cut-eye roller chamber uses anchor belt mesh as permanent support and anchor cable reinforcement support, and is supported simultaneously with the cut-eye widening roadway; two single hydraulic props with 4.5m U29 steel beams are installed in the cut-eye widening roadway as passive support, with an overlap of no less than 400mm with the top beam of the cut-eye guide tunnel support, and the spacing between the single hydraulic props is 1800mm×1600mm, and the passive support distance from the widening face is no more than 5m.

[0014] Furthermore, the safety measures for top-down construction are as follows:

[0015] (1) Separate the coal chute from the walkway. The walkway is set in the roadway between the west side of the roadway and the first row of single hydraulic props with a width of 1.0m. Every 40 meters, anti-slag nets are installed in the walkway, and every 20 meters, a transverse gangue barrier is installed. The transverse gangue barrier is composed of hydraulic props and diamond mesh. The diamond mesh is laid upright on the single hydraulic props, and the diamond mesh is laid from the bottom plate to the top plate. Anti-slag rolling board is installed at the end of the gangue barrier to the side of the walkway. Every 20m in the coal chute, an anti-flying gangue belt or a reverse coal flow barrier is installed.

[0016] (2) The chute frame is fixed with ground anchors. The ground anchors are anchored with Φ22mm×2000m anchor rods and arranged at the four corners of the chute frame. They are secured with 40T scraper machine anchor chains. After the chute components are installed, the frame is leveled and aligned, and ground anchors are installed for fixation.

[0017] (3) When the coal chutes inside the cut are connected, the following fixing method shall be adopted: two ground anchors shall be installed for every five sections of chutes using 335#φ22 threaded anchor rods. As the distance of the cut increases, a new scraper conveyor shall be added every 80m to continue transporting gangue;

[0018] (4) During the tunneling process, due to the steep slope of the roadway, in order to prevent coal and gangue from escaping or rolling down and injuring people, point pillars should be installed every 1.6m and old belts or diamond mesh should be laid to separate the coal chute from the pedestrian walkway, and a gangue net should be installed horizontally every 30m; when constructing on the pedestrian walkway side, a hemp rope should be tied to the roadway side for easy access for personnel to hold on to when going up and down.

[0019] Furthermore, the safety measures for bottom-up construction are as follows:

[0020] (1) No eaves are left at the face. After the support is in place, the face is sealed with a gangue net to prevent the gangue from sliding down and to provide safety cover for the face construction personnel. The gangue net is made of polyester fiber reinforced plastic net used in coal mines. The mesh size is no more than 100×100mm. The gangue net is connected to the support net by S-hooks made of φ6mm steel bars around the perimeter. Two steel pipes are added 500mm above the bottom plate as a skeleton. Waste chisels are inserted into both ends of the skeleton and the chisels are inserted into the drill holes on both sides of the roadway. T-shaped nails are inserted into the bottom plate through the mesh holes. The spacing between the S-hooks and T-shaped nails is no more than 500mm.

[0021] (2) After the roof and sidewalls are fully supported, the face rock retaining net is removed. When the face rock collapses and the retaining net cannot play a protective role, the face rock collapse prevention measures are strengthened. Three threaded anchor bolts with a length of not less than 2m are installed in each cycle. The anchor bolts are located not less than 0.3m below the roof of the roadway and not more than 1m away from the sidewalls. The face rock sealing anchor bolts are arranged alternately with the anchor bolts of the previous cycle. Each anchor bolt is used in conjunction with W-plates and wooden boards to seal the face. The face rock sealing anchor bolts and wooden boards are not removed during blasting. When the tunnel is 5 meters before breakthrough, advance exploratory holes are drilled at the face. The construction method of exploration and excavation is adopted, and the roof control is narrowed.

[0022] (3) When laying the chute, within 10m below the upper end of the chute, the chute shall be blocked with a rock block to prevent personnel from sliding down the rock; the accumulated loose rock at the chute laying location shall be removed, the chute shall be laid flat and fixed with double-strand No. 8 iron wire, and a set of ground anchors shall be installed every 10m of the chute and fixed with No. 8 iron wire; a set of rock block shall be installed every 20m on the sidewalk, and the rock block shall be made with the support pillars in the roadway and steel pipes or old anchor rods, and the processing height shall not be less than 0.4m;

[0023] (4) A set of buffer clips is installed every 40m in the coal chute. 10m above the buffer clips, a waste conveyor belt is used to hang the chute from the roof. The bottom of the chute is 0.1~0.2m higher than the roadway floor. The bottom of the chute is equipped with four U-shaped steels to install buffer clips. The two columns of the buffer clips are anchored with anchor rods. The angle between the bottom of the columns and the floor is greater than 50°. Finally, two U-shaped steels are laid horizontally. In the end, the buffer clips play a role in blocking the gangue and slowing down the flow of coal.

[0024] Furthermore, the safety measures for further refurbishment are as follows:

[0025] (1) Use old conveyor belts or biaxially stretched plastic nets to set up isolation nets to block the coal chute on both sides. Use small chains or double-strand No. 8 iron wire to fix the old conveyor belts or biaxially stretched plastic nets to the single support. The height of the isolation net is not less than 1.5m and the lower part of the isolation net must contact the hard bottom. Leave the coal shoveling channel in the isolation net of the shoveling face and below within 2m. The coal shoveling channel will not be blocked and will move down with the face. During blasting, the height of the isolation net on the sidewalk within 5m above and below the blasting point will be increased to the roof.

[0026] (2) The sidewalk is set in the roadway between the west side of the roadway and the first row of single hydraulic props. The sidewalk has a net width of 1.0m, is equipped with a staircase, and a hemp rope is laid along the single prop or the roadway anchor. The hemp rope is firmly fixed to the roadway anchor or the single prop with iron wire. The height of the hemp rope is in line with the height of the hand holding, so that it is convenient for people to go up and down to hold on.

[0027] (3) A set of lifting heads is set up every 20m in the coal chute, and a set of coal flow buffer barriers is set up directly below the lifting heads. Full-height protective nets are set up every 40m along the inclined direction in the sidewalk and the cutting and widening roadway. The two sets of full-height protective nets are arranged alternately. A transverse rock barrier is installed every 20m. The height of the transverse rock barrier is not less than 0.5m. The transverse rock barrier must be placed on a hard base. Both ends are fixed to the single support with small chains. The two sets of transverse rock barriers are arranged alternately. The full-height protective net is composed of hydraulic support and diamond mesh. The diamond mesh is laid upright on two or three single hydraulic support adjacent to the direction. The diamond mesh is laid from the bottom plate to the top plate and fixed at least three times on the single support. The support is supported by wooden blocks. The transverse rock barrier is made of 2-inch steel pipe or T-shaped steel and the surface is covered with 8# iron wire diamond mesh.

[0028] The beneficial effects of this invention are as follows:

[0029] This invention provides a rapid construction method for face cutting in steeply inclined coal seams. It summarizes the construction process for face cutting in steeply inclined coal seams, employing alternating excavation from two faces, phased construction, and overall widening. It also provides support techniques and safety measures, creatively proposing bottom-to-top coal and gangue transportation and relay transportation technologies for steeply inclined coal seams, and a buffering technology for top-to-bottom coal and gangue transportation to prevent coal and gangue from slipping and damaging the supports. This construction method can effectively shorten the construction cycle for face cutting in steeply inclined coal seams, and the construction process is safe and reliable. Attached Figure Description

[0030] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0031] Figure 1 This is a schematic diagram of the steeply inclined coal seam face cutting roadway structure in Embodiment 1 of this application.

[0032] Figure 2 This is a schematic diagram of the structure during top-to-bottom construction in Embodiment 1 of this application.

[0033] Figure 3 This is a schematic diagram of the structure during construction from bottom to top in Embodiment 1 of this application.

[0034] In the diagram, 1 is the track roadway, 2 is the transport roadway, 3-1 is the first section of the cut-in guide tunnel, 3-2 is the second section of the cut-in guide tunnel, 3-3 is the cut-in widening and shaving roadway, 4 is the scraper conveyor, 5 is the belt conveyor, 6 is the area to be constructed, 7 is the plastic chute, and 8 is the buffer card. Detailed Implementation

[0035] To enable those skilled in the art to better understand the technical solutions of this invention, the technical solutions of the embodiments of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of this invention.

[0036] Example 1

[0037] The span of the 11105 fully mechanized mining cutter at Huafeng Coal Mine is 7.6m, and its length is 250m. For example... Figure 1 As shown, track roadway 1 in working face 11105 is at level -450m, and transport roadway 2 is at level -608m. The total length of the cut is 260m, with an average dip angle of 32°. Track roadway 1 is located before transport roadway 2. If conventional construction is carried out from bottom to top, it will take two months, delaying the entire production sequence.

[0038] To avoid delaying the continuation of the project, this embodiment employs a rapid construction method for face cutting in steeply inclined coal seams, combined with... Figure 1-3 The details are as follows:

[0039] 1. Construction process

[0040] (1) One tunneling operation includes constructing the first section 3-1 of the pilot tunnel from top to bottom in the track roadway 1 until the transport roadway 2 is in place, and then constructing the second section 3-2 of the pilot tunnel from bottom to top in the transport roadway until it is completed. The pilot tunnel is constructed with a width of 3.6m and a height of 2.5m; specifically including:

[0041] A. Construction proceeds from top to bottom, tunneling along the roof of the coal seam, using laser orientation, blasting to drop coal, manual loading, and using scraper conveyor 4 to relay and transport it to track roadway 1, and then using belt conveyor 5 in track roadway 1 to transport it to the gangue bin at the -450m level; using forward-exploring beams for temporary support;

[0042] B. Construction proceeds from bottom to top, with coal being blasted at the face and discharged via plastic chute 7 to the outlet below the cut, then discharged by the EBZ-200L tunneling machine to the rear DTL120 / 100 / 2×125 belt conveyor, and then transferred to the SZZ-730 / 75 scraper conveyor in transport roadway 2; after being crushed by the crusher, the coal and gangue enter the shuttle car buffer, and the shuttle car unloads the coal and gangue to the second section of the belt according to the belt operation, using the front extension beam for temporary support.

[0043] (2) The second widening and shaving is carried out by a concentrated team to widen the cut to the full width of the cut. The cut widening and shaving roadway 3-3 is constructed according to the rough width of 4.2m and the rough height of 2.5m. Specifically, it includes: widening and shaving along the east side of the cut guide tunnel, blasting coal, manual coal shoveling, and self-flowing through plastic chutes 7. Coal is transported using a roadway tunneling machine and belt conveyor. After blasting, DW28-250 / 100 or DW25-250 / 100 single props are used in conjunction with six-hole steel belts or φ300mm×3500mm semi-circular timbers for temporary support, with one beam and two pillars.

[0044] 2. Support design:

[0045] (1) One-time excavation: The cut-in guide tunnel is excavated with a rough width of 3.6 meters and a rough height of 2.5 meters. Permanent support is adopted with anchor belt mesh. The roof support material is 600# high-strength threaded steel resin anchor bolts with a row spacing of 800×800mm. The two sides are supported by φ335# high-strength threaded steel resin anchor bolts, with row spacing of 800×800mm and 800×1600mm respectively. W steel strips are used for the roof of the cut-in, and W protective plates are used for the two sides with a row spacing of 800mm. 6300mm anchor cables are used for reinforcement support with a row spacing of 1600×1600mm. The anchor cable reinforcement support is no more than 2m away from the face. Two single hydraulic props are installed in the cut-in in conjunction with U-shaped steel roof beams as passive support with a row spacing of 1500×1600mm.

[0046] (2) Second expansion and sizing: The roadway for expansion and sizing is constructed with a rough width of 4.2m and a rough height of 2.5m. Permanent support is adopted using anchor belt mesh. The roof support material is 600# high-strength threaded steel resin anchor bolts with six-hole W steel strips, and the spacing between the anchor bolts is 800×800mm; the east side uses 335# high-strength threaded steel anchor bolts with W-plates, and the spacing between the anchor bolts is 800×800mm. The anchor bolts on the side are no more than 1100mm behind the face. φ22mm×6300mm anchor cables are used for reinforcement support, and the spacing between the anchor cables is 1600mm×1600mm. The maximum distance between the reinforced support anchor cables and the face is no more than 5m. The overlap between steel strips shall be no less than 200mm; the permanent support of the cut-eye roller chamber shall use anchor belt mesh as permanent support, reinforced by anchor cables, and supported simultaneously with the cut-eye widening roadway; two single hydraulic props with 4.5m U29 steel beams shall be installed in the cut-eye widening roadway as passive support, with an overlap of no less than 400mm with the top beam of the cut-eye guide tunnel support, and the spacing between the single hydraulic props shall be 1800mm×1600mm, and the maximum distance of the passive support from the widening face shall not exceed 5m.

[0047] 3. Safety Measures

[0048] (1) The safety measures for top-down construction are as follows:

[0049] The coal chute and the walkway are separated. The walkway is 1.0m wide and located in the roadway between the west side of the roadway and the first row of single hydraulic props. Every 40 meters, a rockfall prevention net is installed in the walkway, and every 20 meters, a transverse rockfall barrier is installed. The transverse rockfall barrier consists of hydraulic props and diamond mesh. The diamond mesh is laid upright on the single hydraulic props, and the diamond mesh is laid from the bottom plate to the top plate. At the end of the rockfall barrier, a rockfall prevention board is installed from the side of the walkway to prevent rockfall from rolling at the head. Every 20 meters in the coal chute, a rockfall prevention belt or a coal flow blocking plate is installed to prevent flying rock.

[0050] The conveyor frame is fixed with ground anchors. The ground anchors are anchored with Φ22mm×2000m anchor rods and arranged at the four corners of the conveyor frame. They are secured with 40T scraper conveyor anchor chains. After the large components of the conveyor are installed, the frame is leveled and aligned, and then ground anchors are installed for fixation.

[0051] When using overlapping coal chutes within the cut-off section, the following fixing method is adopted: two ground anchors are installed for every five chute sections using 335# φ22 threaded anchor bolts. As the distance between cut-off sections increases, a new scraper conveyor is added every 80m to continue transporting gangue.

[0052] During the tunneling process, due to the steep slope of the roadway, in order to prevent coal and gangue from escaping or rolling down and injuring people, anchor posts should be installed every 1.6m and old conveyor belts or diamond mesh should be laid to separate the coal chute from the pedestrian walkway, and a gangue retaining net should be installed horizontally every 30m; when constructing on the pedestrian walkway side, a hemp rope should be tied to the roadway side for easy access for personnel to hold onto when going up and down.

[0053] (2) The safety measures for bottom-up construction are as follows:

[0054] No eaves are left at the face. After the support is in place, a rockfall retaining net is used to seal the face to prevent rockfall from the face and to provide safety cover for the workers at the face. The rockfall retaining net is made of polyester fiber reinforced plastic net used in underground coal mines, with a mesh size of no more than 100×100mm. The perimeter of the rockfall retaining net is connected to the support net by S-hooks made of φ6mm steel bars. Two steel pipes are added 500mm above the bottom plate as a skeleton. Used chisels are inserted into both ends of the skeleton and inserted into the drill holes on both sides of the roadway. T-shaped nails are inserted into the bottom plate through the mesh holes. The spacing between the S-hooks and T-shaped nails is no more than 500mm.

[0055] After the roof and sidewalls are fully supported, the face rock retaining net is removed. If the face rock collapses and the retaining net cannot provide protection, strengthen the anti-collapse face rock measures. Install three threaded anchor bolts with a length of not less than 2m in each cycle. The anchor bolts should be evenly distributed at a position not less than 0.3m below the roof and not more than 1m away from the sidewalls. The face rock sealing anchor bolts are arranged alternately with the anchor bolts of the previous cycle. Each anchor bolt is used in conjunction with W-plates and wooden boards to seal the face. The face rock sealing anchor bolts and wooden boards are not removed during blasting. When the tunnel is 5 meters before breakthrough, advance exploratory holes are drilled at the face. The construction method of exploration and excavation is adopted, and the roof control is narrowed.

[0056] When laying the chute, the chute should be blocked with rock retainers within 10m below the top end to prevent personnel from slipping down the rock. The accumulated loose rock at the chute laying location should be cleared, and two people should work together to lay the chute flat and fix it with double-strand No. 8 iron wire. A set of ground anchors should be installed every 10m of the chute and fixed with No. 8 iron wire. A set of rock retainers should be installed every 20m on the sidewalk. The rock retainers should be installed with the help of the support pillars in the tunnel and steel pipes or old anchor rods, and the processing height should not be less than 0.4m.

[0057] A set of buffer blocks is installed every 40m in the coal chute. 10m above the buffer blocks, a discarded conveyor belt is used to suspend the chute from the roof. The lower end of the chute is 0.1~0.2m higher than the roadway floor. The lower end of the chute is equipped with four U-shaped steel buffer blocks. The upper ends of the two columns of the buffer blocks are anchored with anchor rods. The angle between the lower end of the columns and the floor is greater than 50°. Finally, two U-shaped steel bars are laid horizontally. In the end, the buffer blocks play a role in blocking and slowing down the coal.

[0058] (3) The safety measures for the second stencil expansion are as follows:

[0059] On both sides of the coal chute, old conveyor belts or biaxially stretched plastic nets are used to set up isolation nets to block the coal chute. The old conveyor belts or biaxially stretched plastic nets are fixed to the individual support pillars with small chains or double-strand No. 8 iron wire. The height of the isolation net is not less than 1.5m, and the lower part of the isolation net must contact the hard ground. The isolation net on the shovel side within 2m below the face is left for the coal shovel, and the coal shovel is no longer blocked and moves down with the face. During blasting, the isolation net on the side of the walkway within 5m above and below the blasting point is increased to the roof.

[0060] The pedestrian walkway is located in the tunnel between the west side of the tunnel and the first row of individual hydraulic supports. The walkway has a clear width of 1.0m and is equipped with a staircase. A hemp rope is laid along the individual support or the tunnel wall anchor. The hemp rope is firmly fixed to the tunnel wall anchor or the supported individual support with iron wire. The height of the hemp rope is suitable for people to hold on to, so that people can easily go up and down.

[0061] A set of lifting heads is installed every 20m in the coal chute, and a set of coal flow buffer barriers is installed directly below the lifting heads. Full-height protective nets are installed every 40m along the inclined direction in the walkway and the cut-and-sweep roadway, with adjacent sets of full-height protective nets staggered. A transverse rock-blocking barrier is installed every 20m, with a height of not less than 0.5m. The transverse rock-blocking barrier must be placed on a hard base and fixed to the individual support pillars at both ends with small chains. Adjacent sets of transverse rock-blocking barriers are staggered. The full-height protective net consists of hydraulic supports and diamond mesh. The diamond mesh is laid upright on two or three individual hydraulic supports adjacent to the direction of the rock flow. The diamond mesh is laid from the bottom plate to the top plate and fixed at no less than three times on each individual support pillar. The supports are supported by wooden blocks. The transverse rock-blocking barrier is made of 2-inch steel pipe or T-shaped steel and covered with 8# iron wire diamond mesh.

[0062] Using the above construction method, the construction period is shortened to 60 days, and the construction process is safe and reliable.

[0063] Although the present invention has been described in detail with reference to the accompanying drawings and preferred embodiments, the present invention is not limited thereto. Various equivalent modifications or substitutions can be made to the embodiments of the present invention by those skilled in the art without departing from the spirit and essence of the invention, and such modifications or substitutions should all be within the scope of the present invention. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should also be covered within the protection scope of the present invention.

Claims

1. A rapid construction method for cutting holes in a large-angle coal seam, characterized in that: It includes one excavation and another expansion. The high-level tunnel of the working face is first located in the low-level tunnel. One excavation includes constructing a cut-eye pilot tunnel from the high-level tunnel from top to bottom until the low-level tunnel is in place, and then constructing a cut-eye pilot tunnel from the low-level tunnel from bottom to top until it is through. The second expansion includes expanding along the side of the cut-eye pilot tunnel to the full width of the cut-eye. The high-level tunnel is a rail tunnel, and the low-level tunnel is a transport tunnel. A tunneling operation includes: The construction is carried out from top to bottom, along the roof of the coal seam, laser orientation is used, the blasted coal is manually loaded, and the scraper conveyor is used to relay the lifting and transportation to the track lane, and then the belt conveyor in the track lane is used to transport the coal; the front exploration beam is used for temporary support; Construction is carried out from bottom to top, with coal falling head-on and blasting. Plastic chutes are used to slide the coal to the lower exit of the cut hole, and then discharged to the rear belt conveyor by the tunneling machine, and then transferred to the scraper conveyor in the transport tunnel; the gangue is crushed by the crusher and then enters the shuttle car buffer. The shuttle car unloads the gangue to the second belt according to the belt operation situation; the front exploration beam is used for temporary support; Safety measures for bottom-up construction are as follows: (1) No umbrella eaves are left at the front, and the front is sealed with a rock blocking net after support; (2) When the primary support of the roof and two sides is completed, the head-on rock retaining net will be removed; when the head-on rock fragments fall and the rock retaining net cannot play a protective role, strengthen the head-on anti-fragmentation measures; when the first 5 meters of the breakthrough, drill an advance exploration hole in the head-on, adopt the construction method of exploration and excavation, and reduce the top control; (3) When laying the chute, use a rock blocking card to block the chute within 10m below the upper end of the chute; remove the accumulated floating rock at the chute laying position, lay the chute flat, and install a rock blocking card on the sidewalk; (4) Buffer cards are installed in the coal chute. The lower end of the chute is 0.1~0.2m higher than the tunnel floor. Buffer cards are installed at the lower end of the chute, and finally two U-shaped steels are laid horizontally.

2. A rapid construction method for cutting holes in a steeply inclined coal seam according to claim 1, characterized in that: The second expansion and brushing includes expanding and brushing along the side walls of the cut eye guide tunnel, manual coal shoveling by blasting coal, self-sliding coal in plastic chutes, and transporting coal using transport tunnel boring machines and belt conveyors.

3. A rapid construction method for cutting holes in a steeply inclined coal seam according to claim 1, characterized in that: The support method for the primary excavation is: permanent support with anchor belt net, the top plate support material is 600# equal-strength threaded steel resin anchor, and the anchor spacing is 800×800mm; the two sides are φ335# equal-strength threaded steel resin anchor, and the anchor spacing is 800×800mm and 800×1600mm respectively; W steel belt is used for the top plate of the cut eye, W guard plate is used for the two sides, and the anchor spacing is 800mm; 6300mm anchor cable is used for reinforced support, and the anchor cable spacing is 1600×1600mm; the maximum distance of anchor cable reinforced support is not more than 2m; two single hydraulic pillars are supported in the cut eye with U-shaped steel top beam as passive support, with a spacing of 1500×1600mm.

4. A rapid construction method for cutting holes in a steeply inclined coal seam according to claim 2, characterized in that: The support method for the second expansion is: permanent support with anchor belt net, the top plate support material is 600# equal-strength threaded steel resin anchor rod with six-hole W steel belt, and the spacing between anchor rods is 800×800mm; the east side is 335# equal-strength threaded steel anchor rod with W guard plate, the spacing between anchor rods is 800×800mm, and the side anchor rod is dragged back to the head by no more than 1100mm; φ22mm×6300mm anchor cable is used for reinforced support, and the spacing between anchor cables is 1600mm×1600mm; the maximum distance between the reinforced support anchor cable and the head is no more than 5m, and the overlap of the steel belt and the steel belt is not less than 200mm; the cut-eye drum chamber uses anchor belt net as permanent support, anchor cable reinforced support, and supports it at the same time as the cut-eye expansion tunnel; two single hydraulic pillars with 4.5m U29 steel beam is used for passive support, with overlap of not less than 400mm with the top beam of the cut-eye pilot tunnel support, the spacing between single hydraulic pillars is 1800mm×1600mm, and the maximum distance of passive support expansion is not more than 5m.

5. A rapid construction method for cutting holes in a steeply inclined coal seam according to claim 1, characterized in that: Safety measures for top-down construction are as follows: (1) Separate the coal chute from the sidewalk. The sidewalk is set in the tunnel between the west side of the tunnel and the first row of single hydraulic pillars with a width of 1.0m. Install a gangue prevention net in the sidewalk every 40m, and install a horizontal gangue barrier every 20m. The horizontal gangue barrier is composed of hydraulic pillars and diamond nets. The diamond nets are vertically laid on the single hydraulic pillars, and the diamond nets are laid from the bottom plate to the top plate. A gangue prevention board is set from the end of the gangue barrier to the sidewalk. An anti-flying gangue belt or a reverse coal flow blocking board is set every 20m in the coal chute. (2) The chute frame is fixed with ground anchors. The ground anchors are anchored with Φ22mm×2000m anchor rods and arranged at the four corners of the chute frame. They are fastened with 40T type scraper anchor chains. After the installation of the large parts of the chute frame is completed, the frame is leveled and aligned, and the ground anchors are driven to fix it; (3) The following fixing method is used when overlapping the coal chutes in the cut: two ground anchors are installed for every five sections of the chute using 335#φ22 threaded anchor rods; as the distance of the cut increases, a new scraper conveyor is added every 80m to transport the gangue; (4) Point pillars are set up every 1.6m to lay old belts or diamond nets to separate the coal chute from the sidewalk, and a gangue-blocking net is installed horizontally every 30m; when constructing the sidewalk side, a brown rope is tied to the side of the tunnel.

6. A rapid construction method for cutting holes in a steeply inclined coal seam according to claim 2, characterized in that: The safety measures for re-expansion are as follows: (1) Use old belts or two-way stretched plastic nets to set up isolation nets on both sides of the coal chute to block the coal chute. The old belts or two-way stretched plastic nets are fixed to the single pillars with small chains or double-strand 8# iron wires. The height of the isolation net is not less than 1.5m, and the lower part of the isolation net contacts the hard bottom; expand the side isolation net within the range of 2m above and below the head to leave the coal shoveling road. The coal shoveling road is no longer blocked and moves down with the head; during blasting, the side isolation net blocking height within 5m above and below the blasting site is increased to the top plate; (2) The sidewalk is set up in the lane between the west side of the lane and the first row of single hydraulic pillars. The net width of the sidewalk is 1.0m. A pedestrian ladder is set up, and a brown rope is laid along the single pillar or the anchor rod of the lane. The brown rope is firmly fixed to the anchor rod of the lane or the single pillar with iron wire. The height of the brown rope meets the handhold height of personnel; (3) A group of chute head lifts are set up at intervals of 20m in the coal chute, and a group of coal flow buffer blocks are set up directly below the chute head lifts. Full-height protective nets are set up at intervals of 40m along the inclined direction in the sidewalks and cut-eye expansion lanes, and two adjacent groups of full-height protective nets are arranged alternately; A horizontal rock-retaining fence is installed at intervals of 20m. The height of the horizontal rock-retaining fence is not less than 0.5m. The horizontal rock-retaining fence is placed on a hard bottom and fixed to the single pillars at both ends with small chains. Two adjacent groups of horizontal rock-retaining fences are arranged alternately. The full-height protective net is composed of hydraulic pillars and diamond nets. The diamond net is vertically laid on two or three adjacent single hydraulic pillars. The diamond net is laid from the bottom plate to the top plate and fixed on the single pillars at no less than three places. The pillars are connected to the top with wooden pads. The horizontal rock-retaining fence is made of 2-inch steel pipes or T-shaped steels, and 8# iron wire diamond nets are laid on the surface.

7. A rapid construction method for cutting holes in a steeply inclined coal seam according to claim 1, characterized in that: In step (1), the slag retaining net is a polyester fiber reinforced plastic net used in coal mines, the mesh size is not greater than 100×100 mm, the slag retaining net is connected to the support net by S hooks made of φ6 mm steel bars, two steel pipes are added 500 mm above the bottom plate as a skeleton, waste drills are inserted into the two ends of the skeleton, and the drills are inserted into the drill holes on both sides of the tunnel, and T-shaped nails are used at the bottom to pass through the mesh holes and insert into the bottom plate, and the spacing between the S hooks and the T-shaped nails is not greater than 500 mm; In step (2), the specific measures to prevent the head-on blast are: three threaded anchor rods with a length of not less than 2 m are installed in each cycle; the anchor rods are located not less than 0.3 m below the tunnel roof and are evenly arranged at a distance of not more than 1 m from the two sides; the head-on anchor rods are arranged alternately with the anchor rods in the previous cycle; each anchor rod is used in conjunction with a W guard plate and a wooden board to seal the head; the head-on anchor rods and wooden boards are not removed during blasting; In step (3), the laying method of the chute is as follows: a group of ground anchors is installed every 10 m of the chute, and the chute is fixed with 8# iron wire; the setting method of the rock blocking card is as follows: a group of rock blocking cards is installed every 20 m on the sidewalk side, and the rock blocking cards are supported by steel pipes or waste anchor rods with the help of pillars in the lane, and the processing height of the rock blocking cards is not less than 0.4 m; In step (4), the method for installing the buffer cards in the coal chute is as follows: a group of buffer cards is installed every 40 m, and a waste belt is used to hang the buffer cards 10 m above the top plate; four U-shaped steels are used to install the buffer cards at the lower end of the chute, and the upper ends of the two columns of the buffer cards are anchored with anchor rods, and the angle between the lower end of the column and the bottom plate is greater than 50°.

Images