Penetrating type anchor cable for two-way constraint on two sides of small coal pillar and construction method

Abstract

The invention relates to the technical field of coal mine tunnel supporting, in particular to a penetrating type anchor cable with two-way constraint on the two sides of a small coal pillar and a construction method.The penetrating type anchor cable comprises a steel strand, a lock and a connecting piece are arranged at the two ends of the steel strand respectively, a rubber ferrule is arranged between the lock and the connecting piece, and the steel strand is sleeved with the rubber ferrule; the connecting piece comprises a conical core arranged on the steel strand in a sleeving mode, a round nut is arranged at the end, facing the lock, of the conical core, an anchor head is arranged at the end, away from the round nut, of the conical core, a connecting ring is arranged at the end, facing the round nut, of the conical core, a plurality of anchor pieces are arranged at the end, facing the anchor head, of the connecting ring, and a spring is arranged between the connecting ring and the round nut. According to the invention, the construction of the two-way opposite anchor cable can be effectively completed on one side of the small coal pillar, and the anchor rod supporting speed and the roadway advancing speed are effectively improved; harmful gases such as gas in a working face goaf of the upper section can be effectively prevented from entering the gob-side entry driving of the section through gaps, and potential safety hazards are eliminated.

Description

Technical Field

[0001] The invention relates to the technical field of coal mine tunnel support, in particular to a penetrating anchor cable with bidirectional constraints on both sides of a small coal pillar and a construction method. Background Art

[0002] At present, small coal pillars have become the main form of normal continuation of working faces in most mining areas. After the upper section working face is mined, a stress reduction zone appears due to the influence of support pressure. In the stress reduction zone, tunnels are dug along the goaf. Although the surrounding rock is in the stress reduction zone, secondary cracks in the coal body are developed and the strength is severely damaged. The edges on both sides of the small coal pillars are prone to loosening and breaking. In the tunneling process, it is necessary to explore the coal pillar posture stability control method of bidirectional anchoring in combination with the fragmentation characteristics of the coal body on the side of the coal pillar.

[0003] The existing side support forms of narrow coal pillars in small coal pillars along goaf roadways are mainly concentrated in support forms such as high-strength threaded steel anchor rods and long anchor cable reinforcement support; the above-mentioned support forms are all unidirectional constrained support, which can provide greater support resistance to the coal pillars in goaf roadways with small coal pillars where the degree of development of coal body cracks is low and the movement and deformation on both sides of the small coal pillars are low, thereby maintaining the integrity of the small coal pillars and better controlling the deformation and instability of the coal pillars. However, after the mining of the upper section working face is completed, the coal wall is withdrawn and the edges of the small coal pillars on both sides are prone to loosening and breaking. The above-mentioned support form cannot control the posture of the coal pillar well, which may easily lead to large deformation and instability on the side of the coal pillar when excavating along the goaf. As a result, some existing two-way tension anchor devices have the following main problems: the construction of the tension anchor cannot be completed on one side of the coal pillar, and the operation is difficult; it cannot prevent harmful gases such as gas in the goaf of the upper section working face from entering the goaf along the goaf in this section through the gap between the anchor and the drill hole, which poses a safety hazard; the anchor head device is generally detachable from the rod body, which greatly reduces the overall strength of the tension anchor device.

[0004] Therefore, there is an urgent need for a penetrating anchor cable and construction method with bidirectional constraints on both sides of a small coal pillar, which can not only effectively complete the construction of bidirectional anchor cables on one side of the small coal pillar, but is also easy to operate, can greatly increase the anchor support speed, and effectively increase the advancement speed of the tunnel; it can also effectively prevent harmful gases such as gas in the goaf of the upper section working face from entering the goaf-side excavation tunnel in this section through the gap between the anchor rod (cable) and the drill hole, effectively eliminating safety hazards. Summary of the invention

[0005] The purpose of the present invention is to provide a penetrating anchor cable with bidirectional constraints on both sides of a small coal pillar and a construction method to solve the problems existing in the above-mentioned prior art.

[0006] To achieve the above-mentioned purpose, the present invention provides the following scheme: a penetrating anchor cable with bidirectional constraints on both sides of a small coal pillar, comprising a steel strand, wherein two ends of the steel strand are respectively provided with a lock and a connector, a rubber ring is provided between the lock and the connector, and the rubber ring is sleeved on the steel strand; the connector comprises a conical core sleeved on the steel strand, a round nut is provided at one end of the conical core facing the lock, an anchor head is provided at one end of the conical core away from the round nut, a connecting ring is provided at one end of the conical core facing the round nut, a plurality of anchor plates are provided on one end of the connecting ring facing the anchor head, and a spring is provided between the connecting ring and the round nut.

[0007] Preferably, a tray is provided at one end of the lock facing the round nut.

[0008] Preferably, the outer surface of the rubber ring is in the shape of a triangular thread.

[0009] Preferably, one end of the conical core facing the lock is fixedly connected with a cylinder, the round nut is installed on an end of the cylinder away from the conical core, and the spring is sleeved on the cylinder.

[0010] Preferably, an anchor head hole is formed on the anchor head, and a central through hole is formed on the conical core and the cylinder, the diameters of the anchor head hole and the central through hole are larger than the diameter of the steel strand, and the diameter of the central through hole is larger than the diameter of the anchor head hole.

[0011] Preferably, a plurality of conical ribs are fixedly connected to the conical core in the circumferential direction, and a groove is slidably connected to the conical rib, and the groove is formed on the anchor plate.

[0012] Preferably, a plurality of single-ear seats are fixedly connected to the connecting ring, the single-ear seats are rotatably connected to double-ear seats, and the double-ear seats are fixedly connected to the anchor plate.

[0013] Preferably, a plurality of barbs are fixedly connected to a side of the anchor sheet facing away from the groove.

[0014] A method for constructing a penetrating anchor cable with bidirectional constraints on both sides of a small coal pillar comprises the following steps:

[0015] S1. Drill holes at small coal pillars in the tunnel;

[0016] S2. Pushing the connecting member into the drill hole;

[0017] S3. Pulling back the steel strand;

[0018] S4. When the steel strand cannot be pulled out by pulling back, the anchor sheet extends out of the drill hole;

[0019] S5. Continue to pull back the steel strand, and when the steel strand cannot be pulled back, install the rubber ring;

[0020] S6. Install the lock.

[0021] Preferably, in step S2, in order to make the anchor plates be in a contracted state before entering the drill hole, a plurality of the anchor plates are tied to the conical core by means of rubber bands.

[0022] The present invention discloses the following technical effects:

[0023] 1. The bidirectional anchor cable of the present invention can realize the construction of the bidirectional anchor cable on one side of the small coal pillar, is easy to operate, can greatly improve the anchor support speed, and thus improve the advancement speed of the tunnel.

[0024] 2. The present invention can prevent harmful gases such as gas in the goaf of the upper section working face from entering the goaf-side tunneling of this section through the gaps through the rubber ring, thereby eliminating safety hazards.

[0025] 3. The length of the steel strand of the present invention can be flexibly adjusted according to the width of the small coal pillars in the actual engineering geological conditions, and can meet the requirements of the complex on-site environment.

[0026] The present invention can not only effectively complete the construction of two-way anchor cables on one side of the small coal pillar, is easy to operate, can greatly improve the anchor support speed, and effectively improve the advancement speed of the tunnel; it can also effectively prevent harmful gases such as gas in the goaf of the upper section working face from entering the goaf-side excavation tunnel in this section through the gap between the anchor (cable) and the drill hole, effectively eliminating safety hazards. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0028] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0029] Figure 2 It is a schematic diagram of the anchor head structure of the present invention;

[0030] Figure 3 It is a schematic diagram of the conical core structure of the present invention;

[0031] Figure 4 It is a schematic diagram of the barb structure of the present invention;

[0032] Figure 5 It is a schematic diagram of the slot structure of the present invention;

[0033] Figure 6 This is a schematic diagram of the connecting ring structure of the present invention;

[0034] Figure 7 It is a schematic diagram of the spring structure of the present invention;

[0035] Figure 8 It is a schematic diagram of the overall structure of the bidirectional anchor cable after construction of the present invention;

[0036] Fig. 9 It is a schematic diagram of the cross-sectional structure of the bidirectional anchor cable after construction of the present invention;

[0037] Among them, 1. Steel strand; 2. Anchor head; 3. Conical core; 4. Anchor plate; 5. Connecting ring; 6. Lock; 7. Tray; 8. Small coal pillar; 9. Drill hole; 10. Round nut; 11. Rubber ring; 12. Spring; 21. Anchor head hole; 31. Cylinder; 32. Conical rib; 33. Center through hole; 41. Barb; 42. Groove; 43. Hinge hole; 44. Double-ear seat; 51. Single-ear seat. DETAILED DESCRIPTION

[0038] The possible implementation schemes found in the art are:

[0039] The patent publication number CN112963186A discloses a method for reinforcing and supporting narrow coal pillars along goaf-digged lanes, comprising the following steps: S1: First, in the mining lane, a tunnel drill or an anchor drill is used to drill horizontal boreholes and symmetrical top and bottom plate inclined boreholes into the narrow coal pillars in the section, and the horizontal boreholes and the top and bottom plate inclined boreholes are arranged in sequence along the length direction of the narrow coal pillars at intervals, and the holes are cleaned after the drilling is completed; S2: In the inclined boreholes of the top and bottom plates of the narrow coal pillars on the side of the mining lane of the section, inclined anchor rods are respectively installed, and inclined anchor rod anchor heads are installed on the ends of the inclined anchor rods exposed from the top and bottom plates to form a single-sided oblique anchoring system; S3: In the mining lane, the exposed section of the installed inclined anchor rod at the coal wall of the narrow coal pillar is passed through the oblique borehole of the tie rod nut, and the tie rod nut is fixed to the coal wall with a nut, and the nut is tightened to apply a certain pre-tightening force; at the same time, the inclined anchor rod installed on the bottom plate is fixed to the inclined anchor rod at the bottom plate. The exposed section of the narrow coal pillar coal wall passes through the oblique drilled hole of the "U" groove reinforcement piece, and the "U" groove reinforcement piece is fixed to the coal wall with a nut, and the nut is tightened to apply a certain pre-tightening force; S4: In the mining tunnel, the bent section of the "U"-shaped reinforcement rod is clamped in the U-shaped groove of the "U" groove reinforcement piece, and the two ends of the "U"-shaped reinforcement rod pass through the reinforcement through holes of the reinforcement nut piece above the "U" groove reinforcement piece, and the reinforcement nuts are tightened at the threads at both ends, and a certain pre-stress is applied to form a longitudinal truss reinforcement structure, forming a single-side transverse limit reinforcement device; S5: The anchor cable is installed in the horizontal borehole and a certain exposed length is retained; S6: A small diameter grouting pipe is inserted into the horizontal borehole, and then the reinforcement material is injected into the horizontal borehole where the anchor cable is installed through the grouting pipe; S7: After the reinforcement material in the horizontal borehole solidifies, the tray and the lock are installed in sequence at the exposed end of the anchor cable, and then a certain pre-tightening force is applied to the anchor cable.

[0040] In step S6 and step S7: the reinforcing material is a Boline reinforcing material or a Marisan reinforcing material.

[0041] The patented method for reinforcing and supporting narrow coal pillars along goaf roadways mainly solves the instability of narrow coal pillars caused by stress concentration during goaf roadway excavation. By strengthening the support for narrow coal pillars, the overall stability of goaf roadways is improved, and the purpose of improving the recovery rate of coal resources is finally achieved. The inclined anchor system composed of inclined anchor rods and longitudinal truss devices prevents the coal wall from spalling. At the same time, grouting through horizontal drilling re-consolidates the loose circle around the anchor cable into an anchor body with a certain bearing capacity, thereby improving the bearing capacity of the coal pillar itself. After the anchor material is consolidated, a certain pre-tightening force is applied to the anchor cable to achieve a better support effect. Compared with other similar solutions, the advantage of this patent is that it reduces the support density while achieving a balance between support cost and support effect.

[0042] Patent publication number CN118933909A discloses a narrow coal pillar reinforcement structure based on double-pull anchor cables, based on a narrow coal pillar located between tunnel A and tunnel B, the wall surface of the narrow coal pillar located on the side of tunnel A is wall surface A, and the wall surface located on the side of tunnel B is wall surface B; the reinforcement structure is specifically as follows: a steel wire mesh is arranged on the wall surface of tunnel A and tunnel B, and a plurality of U-shaped shed supports are evenly and spacedly arranged on the wall surface of tunnel A and tunnel B and on the steel wire mesh; on the rock mass of the narrow coal pillar, avoiding the position of the U-shaped shed support Multiple through holes are evenly arranged horizontally and vertically, and the through holes are mounting holes for anchor cables; an anchor cable is arranged through each mounting hole, and the two ends of each anchor cable extend to the outside of wall surface A and wall surface B respectively; auxiliary tools, each tensioning auxiliary tool is a tray and a lock sequentially mounted on the end of the anchor cable, the tray is fixed on wall surface A or wall surface B, the lock is used to lock the anchor cable, and the bottom of the lock is in contact with the tray; among them, the tensioning auxiliary tool is used to cooperate with the tensioner to tension and pre-tighten the two ends of the anchor cable; the pre-tightened anchor cable is used to achieve bidirectional reinforcement support for narrow coal pillars.

[0043] At least two hoops are arranged at intervals in the middle section of each anchor cable.

[0044] The spacing distance between the multiple mounting holes in the horizontal direction is 400 mm, and the spacing distance in the vertical direction is 800 mm.

[0045] The end of each anchor cable extends out of wall A or wall B by at least 0.5m.

[0046] The second technical solution adopted by the patent is a method for installing a narrow coal pillar reinforcement structure based on double-pull anchor cables, which is based on a narrow coal pillar reinforcement structure based on double-pull anchor cables and a prefabricated anchor cable. The prefabricated anchor cable is a casing sleeved on one end of the anchor cable, and the casing is fixed with a hoop; the installation method comprises the following steps: S1. When excavating tunnel A, a through hole is drilled from one side of tunnel A to the rock body of the narrow coal pillar, which is the installation hole of the prefabricated anchor cable, and the installation holes are evenly arranged. The prefabricated anchor cable is inserted into each installation hole; and both ends of the prefabricated anchor cable pass through both sides of the narrow coal pillar; and one end of the prefabricated anchor cable provided with the casing extends to one side of tunnel B; each installation hole is pre-sealed with a foaming agent, and then each prefabricated anchor cable and its location are grouting pipes. Grouting reinforcement is performed in the gap of the installation hole; after the grouting is completed, the tray and the lock are successively inserted into the end of the anchor cable on the side of tunnel A and fixed; after the slurry is quickly solidified, the tensioning device is used to apply a pre-tightening force to realize the pre-tightening reinforcement of the anchor cable on the side of the narrow coal pillar on the tunnel A; S2, when excavating to tunnel B, after the end of the prefabricated anchor cable is exposed, the excess length of the anchor cable is cut off while ensuring that the end of the prefabricated anchor cable exceeds the wall of the narrow coal pillar, the anti-static sleeve is removed, and the tray and the lock are successively installed on the end of the anchor cable on the side of the tunnel B; according to this method, each prefabricated anchor cable on the side of tunnel B is cut and the tensioning auxiliary tools are installed; finally, each anchor cable on the side of tunnel B is tensioned and pre-tightened, that is, the two-way reinforcement support of the narrow coal pillar is realized. In S1, before the anchor cable is installed into the installation hole, a grouting pipe is first fixed in parallel to the anchor cable, and a grouting plug is mounted on the anchor cable and adjacent to the outer walls of both sides of the narrow coal pillar.

[0047] This patent sets a wire mesh and a U-shaped shed support on the narrow coal pillar, and evenly arranges multiple anchor cables horizontally and vertically on the rock mass of the narrow coal pillar, avoiding the position of the U-shaped shed support, and then installs trays and locks on both sides of the anchor cables, and pre-tightens both ends of the anchor cables through tensioning tools, thereby achieving two-way reinforcement support, improving the support strength of the narrow coal pillar, solving the problem of tight mining continuity in the mine, and avoiding the formation of isolated island surfaces in the mining area due to skipping mining.

[0048] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0049] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0050] Reference Figure 1-Figure 9The present invention provides a penetrating anchor cable with bidirectional constraints on both sides of a small coal pillar, comprising a steel strand 1, wherein a lock 6 and a connector are respectively arranged at both ends of the steel strand 1, a rubber ring 11 is arranged between the lock 6 and the connector, and the rubber ring 11 is sleeved on the steel strand 1; the connector comprises a conical core 3 sleeved on the steel strand 1, a round nut 10 is arranged at one end of the conical core 3 facing the lock 6, an anchor head 2 is arranged at one end of the conical core 3 away from the round nut 10, a connecting ring 5 is arranged at one end of the conical core 3 facing the round nut 10, a plurality of anchor sheets 4 are arranged on one end of the connecting ring 5 facing the anchor head 2, and a spring 12 is arranged between the connecting ring 5 and the round nut 10.

[0051] The bidirectional anchor cable of the present invention can realize the construction of the bidirectional anchor cable on one side of the small coal pillar 8, is easy to operate, can greatly improve the anchor support speed, and further improve the advancement speed of the tunnel.

[0052] The rubber sleeve 11 of the present invention can prevent harmful gases such as gas in the goaf of the upper section working face from entering the goaf-side tunneling of this section through the gap, thereby eliminating potential safety hazards.

[0053] The length of the steel strand 1 of the present invention can be flexibly adjusted according to the width of the small coal pillar 8 in actual engineering geological conditions, and can meet the requirements of complex on-site environments.

[0054] The present invention can not only effectively complete the construction of two-way anchor cables on one side of the small coal pillar 8, is easy to operate, can greatly improve the anchor support speed, and effectively improve the advancement speed of the tunnel; it can also effectively prevent harmful gases such as gas in the goaf of the upper section working face from entering the goaf-side excavation tunnel in this section through the gap between the anchor (cable) and the drill hole, effectively eliminating safety hazards.

[0055] In a further optimized solution, a tray 7 is provided at one end of the lock 6 facing the round nut 10. Through the tray 7, the lock 6 can effectively tension and pre-tighten the steel strand 1.

[0056] In a further optimized solution, the outer surface of the rubber sleeve 11 is triangular threaded, so that the rubber sleeve 11 can be effectively drilled into the hole 9.

[0057] The rubber ferrule 11 is pre-installed in the middle of the steel strand 1. The length of the rubber ferrule 11 is 100-400mm, and the outer diameter of the rubber ferrule 11 is 2-10mm. The total diameter of the steel strand 1 after the rubber ferrule 11 is put on is equal to the diameter of the borehole 9. The function of the rubber ferrule 11 is to prevent the gas and other toxic gases in the goaf of the upper section from entering the goaf-side tunnel in this section through the gap between the steel strand 1 and the borehole 9 after the construction of the tension anchor cable is completed. The outer surface of the rubber ferrule 11 is a triangular thread shape, which is also for the convenience of being inserted into the borehole.

[0058] In a further optimized solution, the end of the conical core 3 facing the lock 6 is fixedly connected with a cylinder 31, the round nut 10 is installed at the end of the cylinder 31 away from the conical core 3, and the spring 12 is sleeved on the cylinder 31. The conical core 3 and the cylinder 31 are integrally formed, which effectively improves the overall strength.

[0059] The spring 12 is sleeved on the cylinder 31, and the spring 12 has a rectangular cross section. The inner diameter of the spring 12 is 1-3 mm larger than the outer diameter of the cylinder 31, and the free length of the spring 12 is 100-150 mm. The upper and lower bottoms of the spring 12 are ground flat. When the anchor plate 4 extends out of the drill hole 9, the spring 12 pushes the connecting ring 5, causing the anchor plate 4 to open immediately.

[0060] According to a further optimization scheme, an anchor head hole 21 is provided on the anchor head 2, and a central through hole 33 is provided on the conical core 3 and the cylinder 31, the diameters of the anchor head hole 21 and the central through hole 33 are larger than the diameter of the steel strand 1, and the diameter of the central through hole 33 is larger than the diameter of the anchor head hole 21.

[0061] The total length of the anchor head 2 is 100-150 mm, and the diameter of the anchor head hole 21 is 1-3 mm larger than the diameter of the steel strand; the anchor head 2 and the steel strand 1 are fixed together by buckling.

[0062] The diameter of the central through hole 33 is 3-5 mm larger than the diameter of the steel strand 1 .

[0063] In a further optimized solution, a plurality of conical ribs 32 are fixedly connected to the circumference of the conical core 3, and a groove 42 is slidably connected to the conical rib 32, and the groove 42 is provided on the anchor sheet 4. The groove 42 moves along the conical rib 32, so that the plurality of anchor sheets 4 can be effectively tilted, so that the anchor sheets 4 are fully opened and stuck on the coal wall.

[0064] By sliding the groove 42 in the anchor sheet 4 on the conical rib 32 on the conical core 3 , the anchor sheet 4 can be well fitted and opened with the conical core 3 , thereby improving the anchoring effect of the anchor sheet 4 .

[0065] In a further optimized solution, a plurality of single-ear seats 51 are fixedly connected to the connecting ring 5, and the single-ear seats 51 are rotatably connected to the double-ear seats 44, and the double-ear seats 44 are fixedly connected to the anchor plate 4. The single-ear seats 51 and the double-ear seats 44 are respectively provided with hinge holes 43, and the hinge holes 43 are penetrated by a rotating shaft, so that the anchor plate 4 can rotate.

[0066] In a further optimized solution, a plurality of barbs 41 are fixedly connected to one side of the anchor plate 4 away from the groove 42. The barbs 41 on the anchor plate 4 are clamped on the coal wall on the other side of the borehole 9, which effectively increases the friction between the anchor plate 4 and the coal wall of the borehole 9 and improves the overall anchoring effect.

[0067] A method for constructing a penetrating anchor cable with bidirectional constraints on both sides of a small coal pillar comprises the following steps:

[0068] S1. Construct a borehole 9 at the small coal pillar 8 in the tunnel; during the tunnel excavation process along the small coal pillar, construct an anchor cable borehole 9 on the side of the small coal pillar 8 in the tunnel, the diameter of the borehole 9 is 2-10mm larger than the diameter of the tension anchor cable (when the anchor plate is in a contracted state), the length of the borehole 9 is equal to the width of the small coal pillar 8, and the length of the tension anchor cable is 200-400mm larger than the width of the small coal pillar 8.

[0069] S2. Push the connector into the borehole 9; construct a tension anchor cable at the position of the constructed borehole 9 on the side of the small coal pillar 8.

[0070] S3. Pull back the steel strand 1; wait until the tension anchor cable is extended into the borehole 9 to a certain position, pull back the steel strand 1, if it can be pulled out, it proves that the anchor piece 4 has not extended from the end of the borehole 9 to the other side of the small coal pillar 8, then continue to extend the tension anchor cable.

[0071] S4. When the steel strand 1 cannot be pulled out, the anchor piece 4 extends out of the drill hole 9; until the steel strand 1 cannot be pulled out when it is pulled back, it proves that the anchor piece 4 has extended out of the end of the drill hole 9.

[0072] S5. Continue to pull back the steel strand 1. When the steel strand 1 cannot be pulled back, install the rubber ring 11; continue to pull back the steel strand 1 until the anchor piece is fully opened and stuck on the coal wall.

[0073] S6. Install the lock 6; install the tray 7 and the lock 6 at the end of the tension anchor cable, and tension and pre-tighten it to form a two-way anchor on both sides of the small coal pillar 8.

[0074] According to a further optimization scheme, in step S2, in order to make the anchor pieces 4 in a contracted state before entering the borehole 9, a plurality of anchor pieces 4 are tied to the conical core 3 by means of rubber bands.

[0075] Working process:

[0076] During the process of excavating a roadway along the small coal pillar, an anchor cable drill hole 9 is constructed on the side of the small coal pillar 8 in the roadway. The diameter of the drill hole 9 is 2-10 mm larger than the diameter of the tension anchor cable (when the anchor plate 4 is in a contracted state). The length of the drill hole 9 is equal to the width of the small coal pillar 8, and the length of the tension anchor cable is 200-400 mm larger than the width of the small coal pillar 8.

[0077] At the position of the drill hole 9 that has been constructed on the side of the small coal pillar 8, a tension anchor cable is constructed. In order to ensure that the anchor plate 4 is in a contracted state before entering the drill hole 9, the anchor plate 4 is tied to the conical core 3 with a rubber band. The rubber band is pulled or cut off after the anchor plate 4 enters the drill hole 9 for 5-10 mm, that is, when the anchor plate 4 enters the drill hole 9, the rubber band is removed, and the tension anchor cable is extended into the drill hole 9 to a certain position. If the steel strand 1 can be pulled out when it is pulled back, it proves that the anchor plate 4 has not extended out of the end of the drill hole 9 to the other side of the small coal pillar 8, then the tension anchor cable is continued to be extended until the steel strand 1 cannot be pulled out when it is pulled back, which proves that the anchor plate 4 has extended out of the end of the drill hole 9, and the barb 41 will be stuck on the coal wall at the end of the drill hole 9 during the process of pulling the tension anchor cable back, and the steel strand 1 is continued to be pulled back until the anchor plate 4 is fully opened and stuck on the coal wall.

[0078] A tray 7 and a lock 6 are installed at the end of the tension anchor cable, and are tensioned and pre-tightened to form bidirectional anchors on both sides of the small coal pillar 8.

[0079] In the description of the present invention, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0080] The embodiments described above are only descriptions of the preferred modes of the present invention, and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should all fall within the protection scope determined by the claims of the present invention.

Claims

1. A penetrating anchor cable with bidirectional constraints on both sides of a small coal pillar, characterized in that: It comprises a steel strand (1), wherein two ends of the steel strand (1) are respectively provided with a lock (6) and a connector, a rubber ring (11) is provided between the lock (6) and the connector, and the rubber ring (11) is sleeved on the steel strand (1); The connecting member comprises a conical core (3) sleeved on the steel strand (1); a round nut (10) is arranged at one end of the conical core (3) facing the lock (6); an anchor head (2) is arranged at one end of the conical core (3) away from the round nut (10); a connecting ring (5) is arranged at one end of the conical core (3) facing the round nut (10); a plurality of anchor plates (4) are arranged on one end of the connecting ring (5) facing the anchor head (2); and a spring (12) is arranged between the connecting ring (5) and the round nut (10).

2. The penetrating anchor cable with bidirectional constraints on both sides of the small coal pillar according to claim 1 is characterized in that: A tray (7) is provided at one end of the lock (6) facing the round nut (10).

3. The penetrating anchor cable with bidirectional constraints on both sides of the small coal pillar according to claim 1 is characterized in that: The outer surface of the rubber ring (11) is in the shape of a triangular thread.

4. The penetrating anchor cable with bidirectional constraints on both sides of the small coal pillar according to claim 1 is characterized in that: The conical core (3) is fixedly connected to one end of the lock (6) with a cylinder (31), the round nut (10) is mounted on one end of the cylinder (31) away from the conical core (3), and the spring (12) is sleeved on the cylinder (31).

5. The penetrating anchor cable with bidirectional constraints on both sides of the small coal pillar according to claim 4 is characterized in that: The anchor head (2) is provided with an anchor head hole (21), and the conical core (3) and the cylinder (31) are both provided with a central through hole (33). The diameters of the anchor head hole (21) and the central through hole (33) are larger than the diameter of the steel strand (1), and the diameter of the central through hole (33) is larger than the diameter of the anchor head hole (21).

6. The penetrating anchor cable with bidirectional constraints on both sides of the small coal pillar according to claim 1 is characterized in that: A plurality of conical ribs (32) are fixedly connected to the conical core (3) in the circumferential direction, and a groove (42) is slidably connected to the conical rib (32), and the groove (42) is formed on the anchor plate (4).

7. The penetrating anchor cable with bidirectional constraints on both sides of the small coal pillar according to claim 1 is characterized in that: A plurality of single-ear seats (51) are fixedly connected to the connecting ring (5), and the single-ear seats (51) are rotatably connected to double-ear seats (44), and the double-ear seats (44) are fixedly connected to the anchor plate (4).

8. The penetrating anchor cable with bidirectional constraints on both sides of the small coal pillar according to claim 6 is characterized in that: A plurality of barbs (41) are fixedly connected to the side of the anchor plate (4) facing away from the groove (42).

9. A construction method of a penetrating anchor cable with two-way constraints on both sides of a small coal pillar, based on the penetrating anchor cable with two-way constraints on both sides of a small coal pillar according to any one of claims 1 to 8, characterized in that: The following steps are involved: S1. Drilling (9) at the small coal pillar (8) in the roadway; S2. Pushing the connecting member into the borehole (9); S3. Pulling back the steel strand (1); S4. When the steel strand (1) cannot be pulled out by pulling back, the anchor sheet (4) extends out of the drill hole (9); S5. Continue to pull back the steel strand (1), when the steel strand (1) cannot be pulled back, install the rubber ring (11); S6. Install the lock (6).

10. The method for constructing a penetrating anchor cable with bidirectional constraints on both sides of a small coal pillar according to claim 9, characterized in that: In step S2, in order to make the anchor sheet (4) in a contracted state before entering the drill hole (9), a plurality of the anchor sheets (4) are tied to the conical core (3) by means of rubber bands.

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