Gob-side entry protection gangue blocking and supporting facility for coal pillar-free mining and construction method of gob-side entry protection gangue blocking and supporting facility

Abstract

The invention relates to a gob-side entry-protecting gangue-blocking and supporting facility for coal-pillar-free mining and a construction method, and the gob-side entry-protecting gangue-blocking and supporting facility is used for supporting a lower exit of a machine roadway and a coal face; the top end of the fixed supporting column is inclined to a machine roadway. And the middle-upper parts of the fixed support columns are connected with the roadway roof through connecting rods. The connecting rod is supported from the middle upper part of the fixed strut to the roadway roof; the device is used for offsetting part of pressure applied to the machine roadway direction by gangue parallel to a coal face and part of vertically downward pressure of a machine roadway top plate. The construction method disclosed by the invention is used for constructing the waste rock blocking and supporting facility. According to the invention, the pressure borne by anchor cables, fixed struts and supporting facilities of the roof of the machine tunnel is reduced. And a better guarantee is provided for waste rock blocking of gob-side entry retaining and stable supporting of a roadway.

Description

Technical Field

[0001] The invention relates to a new technology for safe mining of coal mines, in particular to gob-side tunnel retaining and supporting facilities for non-coal pillar mining, and a construction method. Background Art

[0002] The no-coal-pillar gob protection refers to the machine gob of the previous mining area, leaving the wind gob of the next mining area, and there is no coal pillar support when leaving the gob, and all mining is done. This method is an advanced underground mining technology that is conducive to the rational development of coal resources, improving coal recovery rate, reducing tunnel excavation, and is beneficial to mine safety and improving the technical and economic benefits of mines. It is not only of practical significance to improve the coal recovery rate of production mines, ease the tension between mining and excavation, and extend the life of mines, but also one of the ways for coal enterprises to improve safety conditions and technical and economic indicators, increase production, increase profits and reduce losses. The gob protection technology has more technical and economic advantages than leaving coal pillars to excavate the gob, both in terms of the use of coal resources and in coal mining methods.

[0003] However, after the supporting coal pillars are removed, due to the influence of mining vibrations and the accumulation of gangue on the upper side of the tunnel after rolling down from the goaf, pressure is generated in the tunnel. Therefore, how to better support the space between the goaf and the machine tunnel becomes a guarantee for safe mining in coal mines.

[0004] During the mining of highly inclined coal, the gangue in the goaf slides downward along the steeply inclined floor of the goaf (toward the machine tunnel). The support facilities installed on the upper wall of the tunnel are used to block the sliding gangue, which causes the gangue to accumulate on the upper wall of the tunnel. The accumulated gangue acts on the support facilities, and the support facilities will be under great pressure, especially the fixed pillars supported between the top and bottom plates of the goaf, which are mainly responsible for bearing the impact of the sliding gangue. The fixed pillars are fixed with anchor cables at the top and bottom ends of the fixed pillars, and the anchor cables are also under great pressure. The tail end of the anchor cable is subjected to downward pulling force on the one hand and lateral shear force on the other hand. Therefore, the supporting structure of the existing support facilities is unevenly stressed, and some structures are under great pressure, which can easily cause gangue impact and deformation of the top and bottom plates, upper and lower walls of the machine tunnel. Summary of the invention

[0005] In order to solve the above technical problems, the present invention provides a kind of gob-side tunnel retaining and supporting facilities and construction method for non-pillar mining.

[0006] Among them, the gob-side protection tunnel and support facilities of the coal pillar-free mining of the present invention are arranged at the exit of the machine tunnel of the high-angle coal seam and the coal mining working face, and support this place; wherein the exit of the coal mining working face has a working face bottom plate inclined at 35° to 55° to the horizontal plane, and a working face top plate parallel to the working face bottom plate; the upper wall of the machine tunnel and the lower wall of the machine tunnel are arranged vertically, and the machine tunnel top plate and the working face top plate are in the same plane. Among them, it includes: A fixed support arranged between the bottom plate and the top plate of the working face, with the top end inclined toward the machine lane.

[0007] A connecting rod is provided to connect the middle and upper part of the fixed support with the machine tunnel top plate. The connecting rod has a first connecting rod end connected with the fixed support and a second connecting rod end connected with the machine tunnel top plate.

[0008] The connecting rod is supported by the upper and middle parts of the fixed pillars toward the machine tunnel roof; it is used to offset the partial pressure exerted by the gangue parallel to the coal mining working face toward the machine tunnel and the partial vertical downward pressure of the machine tunnel roof.

[0009] For example, the above-mentioned gob-side protection tunnel rock blocking and support facilities for non-pillar mining, wherein a hydraulic support is detachably provided between the machine tunnel floor and the machine tunnel roof, specifically, it is advancedly supported between the machine tunnel floor and the machine tunnel roof before the coal mining working face is advanced, and is removed after the coal mining working face is advanced; The invention comprises a hydraulic support supported below the second end of the connecting rod, and a wooden pad is arranged between the top end of the hydraulic support and the connecting rod.

[0010] As described above, the gob-side protection tunnel and support facilities for non-pillar mining, wherein the working face roof is provided with a first anchor cable, the front end of the first anchor cable is driven into the working face roof, the tail end passes downward through the fixed support, and is anchored to the connecting rod below the fixed support, specifically to the first end of the connecting rod; the first anchor cable is vertically arranged; A second anchor cable is arranged on the machine tunnel top plate, a front end of the second anchor cable is driven into the machine tunnel top plate, and a rear end is anchored to the second end of the connecting rod.

[0011] As mentioned above, in the gob-side protection tunnel gangue retaining and supporting facilities of the pillar-free coal mining, a column cap is provided at the connection between the connecting rod and the roof of the tunnel.

[0012] The column cap is a right-angled wedge protruding upward and is used for embedding into the top plate of the machine lane.

[0013] The lower part of the wedge is a right-angled wedge-shaped groove, and the upper part of the second end of the connecting rod intersects the end surface perpendicularly to form an end wedge, which is inserted into the wedge-shaped groove.

[0014] One of the faces constituting the right-angled wedge has an anchor hole through which the second anchor rod passes, and the tail end of the second anchor cable passes through the anchor hole and is anchored to the second end of the connecting rod.

[0015] Both sides of the right-angle wedge are provided with brims for fitting against the top plate of the machine lane.

[0016] As mentioned above, the gob-protecting and supporting facilities for the coal-pillar-free mining, wherein a T-shaped steel belt is arranged on the roof of the machine tunnel, starting from the second end of the connecting rod and attached to the roof of the machine tunnel to the lower wall of the tunnel.

[0017] Anchor nets are installed on the top plate of the machine tunnel, the upper wall of the tunnel and the lower wall of the tunnel, and are pressed against the rock wall by T-shaped steel belts.

[0018] As mentioned above, in the gob-side tunnel retaining and supporting facilities for pillar-free coal mining, the fixed pillars are I-beams, and long holes for the passage of anchor cables are provided on the webs at the upper two-thirds of the fixed pillars.

[0019] The connecting rod is an I-beam, and anchor holes for passing anchor cables are arranged on the webs at the first end and the second end of the connecting rod.

[0020] The distance between the outer sides of the two flanges of the I-beam of the connecting rod is smaller than the distance between the inner sides of the two flanges of the I-beam of the fixed support, so that the connecting rod is inserted into the two flanges of the fixed support.

[0021] As mentioned above, in the gob-side tunnel retaining and supporting facilities for pillar-free coal mining, the connecting rod is arranged horizontally; the first end of the connecting rod is connected to the fixed support at two-thirds from bottom to top.

[0022] The top of the fixed support is inclined toward the machine lane, so that the fixed support and the bottom plate of the working surface form an angle of 70°-80°; The third anchor cable is driven into the upper wall of the machine tunnel in a direction perpendicular to the upper wall of the machine tunnel to support the upper wall of the machine tunnel.

[0023] The construction method of the present invention is used to construct the gangue retaining and supporting facilities along the goaf of the above-mentioned non-coal pillar mining, including the construction in the leading stage and the construction in the lagging stage; The advanced stage construction includes the following steps: Before the coal mining working face is advanced, pillar gaps are constructed in the working face bottom plate, and column cap gaps suitable for the column caps are constructed in the machine tunnel top plate.

[0024] Drive anchor holes into the gaps in the column caps on the upper wall of the machine tunnel and the top plate of the machine tunnel;.

[0025] Install the second anchor cable, the third anchor cable and the column cap.

[0026] Insert the lower end of the fixed pillar into the pillar gap and connect the upper end to the top; connect the upper and middle part of the fixed pillar to the first end of the connecting rod, pass the second anchor cable through the column cap and tension and tighten it.

[0027] Support the hydraulic strut below the second end of the connecting rod.

[0028] Among them, the construction of the lag stage includes the following steps: Remove the hydraulic support; tension and tighten the free space at the tail end of the second anchor cable.

[0029] After the goaf is cut and the pressure is relieved, the free margin generated at the tail end of the second anchor cable is tensioned and tightened again.

[0030] The following steps are also included: Before the coal mining face is advanced, anchor holes are driven into the face roof and the first anchor cable is installed.

[0031] After passing the first anchor cable through the upper middle part of the fixed support, it is connected to the end of the connecting rod and tensioned and tightened.

[0032] The construction in the lagging stage also includes the following steps: tensioning and tightening the movable margin generated at the tail end of the first anchor cable, and then removing the hydraulic support.

[0033] The following steps are also included: Before the column cap, first install the anchor net, reserve a space on the anchor net for installing the column cap, and insert the right-angled wedge of the column cap through the space and into the notch of the column cap, with the brim of the cap pressing the anchor net.

[0034] After the second anchor cable passes through the column cap, it passes through the second end of the connecting rod and the T-shaped steel belt, and then the end of the second anchor cable is tensioned and tightened.

[0035] Beneficial technical effects: The present invention utilizes the function of the connecting rod to transfer part of the pressure exerted by the gangue on the fixed pillars toward the machine tunnel to the top plate of the machine tunnel, thereby offsetting the pressure of the top plate of the machine tunnel, reducing the pressure on the first anchor cable, the fixed pillars, and the supporting facilities of the top plate of the machine tunnel, and providing better protection for the gangue retaining along the goaf and the stable support of the tunnel. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 A schematic diagram of the force of the rock retaining and supporting facilities of the present invention; Figure 2 It is a schematic diagram of the structure of the rock retaining and supporting facilities of the present invention, mainly showing the structure of the rock retaining and supporting facilities in the advanced stage; Figure 3 It is a schematic diagram of the structure of the rock retaining and supporting facilities of the present invention, mainly showing the structure of the rock retaining and supporting facilities in the lagging stage; Figure 4 It is a schematic diagram of the connection relationship between the second end of the connecting rod and the column cap, anchor net, T-shaped steel belt, and hydraulic support.

[0037] Figure 5 It is a schematic diagram of the connection relationship between the first anchor cable, the fixed support and the first end of the connecting rod.

[0038] Figure 6 It is a schematic diagram of the column cap structure.

[0039] The accompanying drawings are marked as follows: working face top plate 1; working face bottom plate 2; fixed support 3; hydraulic support 4; transport belt 5; machine tunnel 6; connecting rod 7; goaf 8; third anchor cable 9; machine tunnel upper wall 10; machine tunnel lower wall 11; machine tunnel bottom plate 12; first anchor cable 13; second anchor cable 14; machine tunnel top plate 15; column cap 16; wooden pad 17; T-shaped steel belt 18; anchor net 19; long strip hole 20; flange 21; web 22; brim 23; column cap notch 24. DETAILED DESCRIPTION

[0040] The invention is applied to a large inclined coal seam with an inclination angle of 35° to 55°.

[0041] In the following examples, the directions of the components are indicated as follows: the direction of the goaf 8 (or coal mining face) is “back”, and the direction of the machine tunnel 6 is “front”; the coal mining face, goaf, and machine tunnel all have a roof and a bottom plate, with the direction of the top plate being “up” and the direction of the bottom plate being “down”.

[0042] In this example, the gob-protecting and supporting facilities for the pillarless mining are set up between the upper wall of the machine tunnel in the steeply inclined coal seam and the lower exit of the coal mining face, as well as inside the machine tunnel, and support is provided there.

[0043] The mined coal seam is inclined to the mined goaf, with an inclination angle of 35° to 55°; The lower exit of the coal mining working face has a working face bottom plate 2 inclined at 35° to 55° to the horizontal plane, and a working face top plate 1 parallel to the working face bottom plate; the machine tunnel top plate 15 is in the same plane as the working face top plate 1. The machine tunnel bottom plate is a horizontal plane; the machine tunnel upper wall 10 and the machine tunnel lower wall 11 are arranged vertically. The lower section of the machine tunnel upper wall is rock mass, and the upper section is coal seam (specifically, a support gap dug out on the coal seam, and fixed columns arranged in the support gap).

[0044] Machine lane 6 is a special-shaped section with a net width of 3300mm, a high wall of 3500mm and a low wall height of 1600mm.

[0045] The machine tunnel is equipped with transport belts 5, pedestrian walkways, drainage ditches, cable racks and other facilities.

[0046] Among them, after the goaf is cut off and the pressure is relieved, the gangue in goaf 8 slides down along the slope of 35°~55° (parallel to the coal mining working face) toward the machine tunnel and is blocked by fixed pillars. The pressure is applied to the fixed pillars. A row of fixed pillars are set on the upper wall of the machine tunnel. Behind the fixed supports are wooden boards. The wooden boards are set between the fixed pillars to prevent the gangue from sliding into the machine tunnel.

[0047] Example 1: The gob-side protection tunnel and support facilities of the non-pillar mining include conventional support facilities, such as a fixed support 3 disposed between the working face bottom plate 2 and the working face top plate 1, with the top inclined toward the tunnel. In particular, a connecting rod 7 is provided to connect the middle and upper part of the fixed support 3 with the tunnel top plate, and the connecting rod is supported by the middle and upper part of the fixed support toward the tunnel top plate 15; Figure 1 The connecting rod 7 is used to offset the partial pressure 01 exerted by the gangue parallel to the coal mining working face in the direction of the machine tunnel with the vertical downward partial pressure of the machine tunnel roof.

[0048] Among them, the upper end of the fixed pillar 3 is fixed by the anchoring tension provided by the first anchor cable 13, and the machine tunnel roof 1 is fixed by the roof support facilities (the advanced support is based on hydraulic pillars and anchor cables and anchor rods; the lagging support is based on anchor cables and anchor rods); therefore, the role of the connecting rod 7 reduces the pressure of the first anchor cable 13 and reduces the pressure of the support facilities of the machine tunnel roof 15.

[0049] refer to Figure 2 During advance support, a hydraulic support 4 is arranged between the machine tunnel bottom plate 12 and the machine tunnel top plate 15. Specifically, it is advanced supported between the machine tunnel bottom plate and the machine tunnel top plate before the coal mining working face is advanced, and is removed after the coal mining working face is advanced; in this example, at least two rows of hydraulic supports 4 are required, one of which is close to the upper wall 10 of the machine tunnel, and is supported by the junction of the upper wall 10 of the machine tunnel and the bottom plate 12 of the machine tunnel to the first end of the connecting rod of the machine tunnel top plate 15. The hydraulic support is inclined forward by 12° (forming an angle of 12° with the vertical direction), and a wooden pad 17 is arranged between the top of the hydraulic support and the connecting rod 7. The soft characteristics of the wooden pad are utilized to make the top of the hydraulic support adapt to the complex structural surface of the supported location.

[0050] In this example, the connecting rod 7 is an I-beam. The I-beam is composed of two flanges arranged in parallel, and a web is vertically arranged between the two flanges. The connecting rod is basically arranged horizontally.

[0051] The connection between the connecting rod and the fixed support is the first end of the connecting rod, and the connection between the connecting rod and the top plate of the machine tunnel is the second end of the connecting rod.

[0052] A second anchor cable 14 is arranged on the machine tunnel roof 15, the front end of the second anchor cable is driven into the machine tunnel roof, and the rear end is anchored to the second end of the connecting rod.

[0053] In order to better support the machine roadway roof, a tray is usually set at the tail end of the anchor cable. In this example, the second anchor cable cancels the tray, or improves the tray, and the tray is replaced by a column cap 16.

[0054] refer to Figure 4 , Figure 6The column cap 16 is arranged at the connection between the connecting rod 7 and the machine tunnel top plate 15. The column cap 16 is a right-angled wedge protruding upward, which is used to be embedded in the column cap notch of the machine tunnel top plate. The bottom of the wedge is a right-angled wedge-shaped groove. The end wedge formed by the upper surface of the second end of the connecting rod and the end surface perpendicularly intersecting is inserted into the wedge-shaped groove. One of the surfaces constituting the right-angled wedge has an anchor hole through which the second anchor rod passes. The tail end of the second anchor cable passes through the anchor hole and is anchored to the second end of the connecting rod. Both sides of the right-angled wedge have cap edges 23 for fitting the machine tunnel top plate.

[0055] Therefore, the column cap 16 of this example can be subjected to two directional forces at the same time, both of which are ultimately transferred to the machineway roof. One direction is the tension of the anchor cable on the column cap, and the other direction is the connecting rod support force perpendicular to the anchor cable tension. Ultimately, the combined force of the two directional forces is perpendicular to the direction of the machineway roof, supporting the machineway roof. The column cap 16 is made of a 10 mm thick steel plate.

[0056] The fixed pillar 3 is made of 11# I-steel and is arranged at a spacing of 500mm along the direction of the machine tunnel. It is driven at a position 500mm close to the upper wall of the tunnel from the bottom plate of the coal mining working face. Waste wood boards, rubber sheets and wire mesh are laid behind the fixed pillar to seal the entire section.

[0057] In this example, the fixed support and the connecting rod are both made of I-beams. The I-beams are composed of two flanges 21 and a web 22. The top of the fixed support 3 is inclined toward the machine lane, so that the fixed support and the bottom plate of the working surface form an angle of 70°-80°.

[0058] The distance between the outer sides of the two flanges of the I-beam of the connecting rod is smaller than the distance between the inner sides of the two flanges of the I-beam of the fixed support, so that the connecting rod is inserted into the two flanges of the fixed support.

[0059] The first end of the connecting rod is connected to the upper middle part of the fixed support, specifically connected to the upper two-thirds of the fixed support.

[0060] As for the way to fix the connecting rod on the fixed pillar, one example is: pin holes can be set on the two flanges of the I-beam at the upper two-thirds of the fixed pillar, and a pin hole can be set on the first end of the connecting rod. A connecting pin is used to pass through the pin hole of the fixed pillar and the pin hole of the first end of the connecting rod respectively, and the first end of the connecting rod is connected to the fixed pillar. The connecting pin transfers the force in two directions of the solid pillar and the machine tunnel top plate. This method has a simple structure, but the shear force on the connecting pin is large. The pin holes drilled on the two flanges of the fixed pillar affect the strength. During construction, it is difficult to ensure that the column cap gap constructed on the machine tunnel top plate and the distance from the upper and middle parts of the fixed pillar must be adapted to the length of the connecting rod, so the construction is slightly difficult.

[0061] Another example of how the connecting rod is fixed on the fixed pillar is: an auxiliary pillar is set, the height of the auxiliary pillar is two-thirds of the height of the fixed pillar, and the bottom end of the auxiliary pillar is supported on the upper wall of the machine lane; after the fixed pillar and the connecting rod are installed in place, the top end of the auxiliary pillar is supported on the first end of the connecting rod, so that the end of the first end of the connecting rod is pressed against the two flanges of the fixed pillar.

[0062] Another example of how the connecting rod is fixed to the fixed support is: Figure 2 , Figure 4 , Figure 5 A first anchor cable 13 is arranged on the top plate of the working face. The first anchor cable is arranged vertically, and the front end of the first anchor cable is driven into the top plate 1 of the working face. A long hole 20 for the anchor cable to pass through is arranged on the web at the upper two-thirds of the fixed pillar (when the I-beam is supported, it mainly relies on the two flanges to resist the bending moment, so the long hole on the web has little effect on the I-beam support); anchor holes are arranged on the webs at the first end and the second end of the connecting rod; the tail end of the first anchor cable is downward, passes through the long hole 20 of the fixed pillar, and is anchored to the first end of the connecting rod; in this way, the tail end of the anchor cable is exposed to a longer distance from the top plate of the working face, and the anchor rod is not subjected to lateral shear force, but only to downward tension. Part of the impact force of the gangue sliding on the fixed pillar is transferred by the connecting rod, and is not completely borne by the anchor cable, so the anchor rod is less stressed.

[0063] refer to Figure 2 , Figure 3 In order to prevent the upper wall of the machine tunnel from spalling (spalling refers to the side wall of the machine tunnel, which causes the coal wall or rock to deform, be damaged and fall off due to the action of mine pressure. This phenomenon usually occurs when there is suspension in the rock layer of the roof of the goaf. When the pressure is transferred to the upper wall of the machine tunnel, the pressure on the upper wall of the machine tunnel increases and it is crushed), a third anchor cable 9 is driven into the upper wall of the machine tunnel to support the upper wall 10 of the machine tunnel; during the specific implementation, it is also necessary to drive at least one row of anchor rods into the upper wall of the machine tunnel, and drive a row of anchor rods or anchor cables downward from the roof of the goaf to fix the upper wall of the machine tunnel.

[0064] refer to Figure 2 , Figure 3 At the same time, other rows of anchor cables and bolts are also required on the top and bottom of the machine tunnel. The top of the machine tunnel is supported by resin anchors, anchor cables and anchor nets, with the spacing between anchors and rows being 800mm, and the spacing between anchor cables and rows being 2400mm; the upper and lower walls of the machine tunnel are supported by resin anchors and anchor nets, with the spacing between anchors and rows being 800mm. The diameter of the anchor is 18mm and the length is 1800mm; the diameter of the anchor cable is 17.8mm and the length is 5200mm.

[0065] At the same time, another row of hydraulic pillars needs to be added between the roofs of the machine tunnel to support the middle position of the machine tunnel. The hydraulic pillars are inclined 12° forward (forming an angle of 12° with the vertical direction).

[0066] Anchor nets 19 are arranged on the machine tunnel roof 15, the tunnel upper wall 10 and the tunnel lower wall 11, and the anchor nets 19 are pressed against the rock wall by T-shaped steel belts 18. The T-shaped steel belts 18 are arranged from the second end of the connecting rod to the machine tunnel roof and the tunnel lower wall; the T-shaped steel belts are tightened by anchor cables and anchor rod trays and supported by the top of the hydraulic support.

[0067] Example 2: The method for constructing gob-side tunnel retaining and supporting facilities in non-coal pillar mining includes construction in an advanced stage and construction in a delayed stage.

[0068] Among them, the advanced stage construction should be carried out when the mining face working face advances no less than 50m. The advanced stage construction includes the following steps: Before the coal mining working face is advanced, pillar gaps are constructed on the working face bottom plate 2, and column cap gaps 24 adapted to column caps are constructed on the machine tunnel top plate 15.

[0069] Drive anchor holes into the upper wall 10 of the machine tunnel, the top plate 15 of the machine tunnel, and the notch 24 of the column cap; and drive the top plate 1 of the working surface into the anchor holes.

[0070] Then install the anchor net 19 and T-shaped steel belt 18, reserve space for installing the column cap on the anchor net, tighten the T-shaped steel belt through the trays of each anchor cable and anchor rod, and press the anchor net against the rock wall. When constructing the anchor rod, the MQT-130 anchor rod machine is used to drill the anchor rod eye. The diameter of the anchor rod eye construction is 28mm, and the depth of the anchor rod eye is 50-100mm shorter than the full length of the anchor rod body. The coal and rock powder in the drilled anchor hole must be cleaned, free of water and debris.

[0071] Install the resin anchor, use MSK-2350 resin medicine roll to stir continuously at a uniform speed for 8 to 15 seconds, then wait for 41 to 90 seconds until the gel is formed and then withdraw the anchor drill. After the waiting time of the anchor agent reaches 5 minutes, the anchor drill can be used to tighten the nut until the plastic pad is pushed out of the tail of the anchor, the tray is close to the wall, and the anchor is exposed 10mm to 50mm from the nut; the pre-tightening torque of the anchor nut shall not be less than 120N.m; and shall not be greater than 150N.m.

[0072] Install the column cap 16 and the connecting rod 7. The right-angled wedge of the column cap passes through the space and is inserted into the column cap notch 24. The cap brim 23 presses the anchor net 19. The second anchor cable 14 passes through the column cap 16, the end of the second end of the connecting rod, and the T-shaped steel belt, and then the second anchor cable 14 is tensioned and clamped.

[0073] Insert the lower end of the fixed support 3 into the support gap, and connect the upper end to the top; after the first end of the connecting rod is supported to the upper middle position of the fixed support, pass the first anchor cable through the long hole 20 of the fixed support, and then insert it into the first end of the connecting rod, and then pull and tighten the first anchor cable 13. The fixed support must be driven on the solid bottom and ensure that it is strong against the mountain. At the same time, install the third anchor cable 9.

[0074] The hydraulic support 4 is installed. The initial support force of the hydraulic support shall not be less than 90KN. The hydraulic support must be tied with an anti-fall rope to prevent the support from unloading and injuring people. One hydraulic support is supported below the second end of the connecting rod; a wooden pad 17 is arranged between the top of the hydraulic support and the connecting rod. The soft properties of the wooden pad are used to make the top of the hydraulic support fit the complex structural surface of the supported part.

[0075] Among them, the construction of the lag stage includes the following steps: The tail end of the first anchor cable 13 is anchored again. Due to the impact of mining and the stress released by the anchor cable, a movable margin is generated. The generated movable margin is tensioned and tightened, and the hydraulic support 4 is removed; the tail end of the second anchor cable 14 is also anchored again.

[0076] After the goaf is cut and the pressure is relieved, the tail end of the second anchor cable 14 is anchored again.

[0077] During the anchor cable construction, the anchor cable should be installed as it is being driven (i.e., the anchor cable should be installed as soon as an anchor cable hole is drilled). After the anchor cable is driven, the T-shaped steel belt must be fixed first before the anchor cable tail end lock is installed, and the anchor cable tail end lock must be tensioned in time to prevent the T-shaped steel belt from sliding down and injuring people. Before tensioning the anchor cable, check whether the tensioning jack and the oil pump oil circuit joints are loose. If any looseness is found, tighten them in time. When tensioning the anchor cable, the tensioning cylinder and the anchor cable should be kept coaxial. After tensioning, the length of the anchor cable tail end exposed outside the lock is 150mm to 250mm.

[0078] The facilities and construction scheme of the present invention were used for experimental implementation. After implementation, a group of monitoring points for the movement of the top and bottom plates of the machine tunnel and the upper and lower walls were set every 30m in the machine tunnel, and a group of monitoring points for the separation of the top plate of the machine tunnel was set every 50m. The changes were observed once a week and recorded in the on-site ledger. At the end of each month, all monitoring point records were submitted to the production technology department for filing and as a basis for analysis. The following Table 1 was obtained: Table 1: Observation table of gob-side entry retention: Near-term monitoring table of top and bottom plates and two sides of the reserved lane section (monitored once a week) According to Table 1 above, it can be seen that the present invention has a good effect, the maximum movement of the roof is 78mm, the maximum convergence of the upper and lower walls of the tunnel is 138mm, and there are no safety accidents during the experimental implementation.

[0079] The above is an exemplary description of the present invention and does not represent the protection scope of the present invention.

Claims

1. The gob-side protection tunnel and support facilities of non-coal pillar mining are set at the exit of the machine tunnel and the coal mining face in the steeply inclined coal seam, and support is provided there; the exit of the coal mining face has a working face floor inclined at 35° to 55° to the horizontal plane, and a working face roof parallel to the working face floor; the upper wall and lower wall of the machine tunnel are arranged vertically, and the machine tunnel roof and the working face roof are in the same plane; It is characterized in that include: A fixed support arranged between the bottom plate and the top plate of the working face, with the top end inclined toward the machine lane; A connecting rod is provided to connect the upper and middle parts of the fixed support to the top plate of the machine tunnel, wherein the connecting rod has a first connecting rod end connected to the fixed support and a second connecting rod end connected to the top plate of the machine tunnel; The connecting rod is supported by the upper and middle parts of the fixed pillars toward the machine tunnel roof; it is used to offset the partial pressure exerted by the gangue parallel to the coal mining working face toward the machine tunnel and the partial vertical downward pressure of the machine tunnel roof.

2. The gob-side tunnel retaining and supporting facility for pillar-free coal mining according to claim 1, characterized in that: A hydraulic support is detachably provided between the machine tunnel floor and the machine tunnel roof, which is specifically provided as an advance support between the machine tunnel floor and the machine tunnel roof before the coal mining working face is advanced, and is removed after the coal mining working face is advanced; The invention comprises a hydraulic support supported below the second end of the connecting rod, and a wooden pad is arranged between the top end of the hydraulic support and the connecting rod.

3. The gob-side tunnel retaining and supporting facility for pillar-free coal mining according to claim 1, characterized in that: The top plate of the working surface is provided with a first anchor cable, the front end of the first anchor cable is driven into the top plate of the working surface, the tail end passes downward through the fixed support, and is anchored on the connecting rod below the fixed support, specifically, anchored on the first end of the connecting rod; the first anchor cable is vertically arranged; A second anchor cable is arranged on the machine tunnel top plate, a front end of the second anchor cable is driven into the machine tunnel top plate, and a rear end is anchored to the second end of the connecting rod.

4. The gob-side tunnel retaining and supporting facility for pillar-free coal mining as claimed in claim 3, characterized in that: A column cap is provided at the connection between the connecting rod and the machine lane roof; The column cap is a right-angled wedge protruding upward and used to be embedded in the top plate of the machine lane; The lower part of the wedge is a right-angled wedge-shaped groove, and the upper part of the second end of the connecting rod intersects the end surface perpendicularly to form an end wedge, which is inserted into the wedge-shaped groove; One of the faces constituting the right-angled wedge has an anchor hole through which the second anchor rod passes, and the tail end of the second anchor cable passes through the anchor hole and is anchored to the second end of the connecting rod; Both sides of the right-angle wedge are provided with brims for fitting against the top plate of the machine lane.

5. The gob-side tunnel retaining and supporting facility for pillar-free coal mining as claimed in claim 3, characterized in that: A T-shaped steel belt is arranged on the top plate of the machine lane, starting from the second end of the connecting rod and attached to the top plate of the machine lane to the lower wall of the lane; Anchor nets are installed on the top plate of the machine tunnel, the upper wall of the tunnel and the lower wall of the tunnel, and are pressed against the rock wall by T-shaped steel belts.

6. The gob-side tunnel retaining and supporting facility for pillar-free coal mining as claimed in claim 3, characterized in that: The fixed support is an I-beam, and a long hole for the anchor cable to pass through is provided on the web at the upper two-thirds of the fixed support; The connecting rod is an I-beam, and anchor holes for passing anchor cables are provided on the webs at the first end and the second end of the connecting rod; The distance between the outer sides of the two flanges of the I-beam of the connecting rod is smaller than the distance between the inner sides of the two flanges of the I-beam of the fixed support, so that the connecting rod is inserted into the two flanges of the fixed support.

7. The gob-side tunnel retaining and supporting facility for pillar-free coal mining as claimed in claim 3, characterized in that: The connecting rod is arranged horizontally; the first end of the connecting rod is connected to the fixed support at two-thirds from bottom to top; The top of the fixed support is inclined toward the machine lane, so that the fixed support and the bottom plate of the working surface form an angle of 70°-80°; The third anchor cable is driven into the upper wall of the machine tunnel in a direction perpendicular to the upper wall of the machine tunnel to support the upper wall of the machine tunnel.

8. A method for constructing gob-side tunnel retaining and supporting facilities for non-pillar mining, which is used to construct gob-side tunnel retaining and supporting facilities for non-pillar mining as claimed in any one of claims 1 to 7, and which is characterized in that it includes construction in the leading stage and construction in the lagging stage; in, The advanced stage construction includes the following steps: Before the coal mining face is advanced, the bottom plate of the working face is constructed with a pillar gap, and the top plate of the machine tunnel is constructed with a column cap gap that is suitable for the column cap. Drive anchor holes into the gaps in the upper wall and column caps of the machine tunnel roof; Install the second anchor cable, the third anchor cable, and the column cap; Insert the lower end of the fixed pillar into the pillar gap and connect the upper end to the top; connect the middle and upper part of the fixed pillar to the first end of the connecting rod, pass the second anchor cable through the column cap and tension and clamp it; Supporting the hydraulic strut below the second end of the connecting rod; Among them, the construction of the lag stage includes the following steps: Remove the hydraulic support; tension and tighten the free space generated at the tail end of the second anchor cable; After the goaf is cut and the pressure is relieved, the free margin generated at the tail end of the second anchor cable is tensioned and tightened again.

9. The construction method according to claim 8, further comprising the following steps: Before the coal mining face is advanced, the face roof is driven into anchor holes and the first anchor cable is installed; After passing the first anchor cable through the middle and upper part of the fixed support, it is connected to the end of the connecting rod for tensioning and tightening; in, The construction in the lagging stage also includes the following steps: tensioning and tightening the movable margin generated at the tail end of the first anchor cable, and then removing the hydraulic support.

10. The construction method according to claim 8, further comprising the following steps: Before the column cap, first install the anchor net, reserve a space on the anchor net for installing the column cap, and insert the right-angled wedge of the column cap through the space and into the notch of the column cap, with the cap edge pressing the anchor net; After the second anchor cable passes through the column cap, it passes through the second end of the connecting rod and the T-shaped steel belt, and then the end of the second anchor cable is tensioned and tightened.

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