Gob-side entry retaining method adopting gangue filling

Abstract

The invention provides a gob-side entry retaining method for gangue filling. The gob-side entry retaining method comprises the following steps: supporting in advance; the first area is filled with gangue with the large particle size to form a grouting cementing part, then the second area is filled with gangue with the small particle size to form a middle blocking part, then the third area is filled with gangue with the large particle size to form a bearing part, and the large particle size is larger than the small particle size; and finally, the filled gangue is tamped. A reinforcing step; an anti-seepage layer spraying step: spraying an anti-seepage material on the side, facing the gob-side entry retaining part, of the grouting cementing part and the side, facing the unfilled gob, of the grouting cementing part; and grouting is conducted, specifically, grouting reinforcement is conducted on the grouting cementation part through a grouting anchor rod. According to the method, efficient utilization of the gangue is achieved, and the surrounding rock stability of gob-side entry retaining is improved; the method solves the problems that in the prior art, a gob-side entry retaining filling method is complex in procedure, a large number of materials need to be input, and the cost is high, and is suitable for large-scale application and popularization.

Description

Technical Field

[0001] The invention relates to the technical field of mine gangue filling, and in particular to a gangue filling gob-side lane retaining method. Background Art

[0002] At present, coal resources, as the main energy source in my country, have an important impact on the country's economic development. In the process of coal resource exploitation, serious problems such as resource waste and environmental damage have occurred, mainly manifested in surface subsidence, destruction and pollution of water resources, accumulation of waste rock mountains, low recovery rate, and environmental damage in mining areas. Waste rock filling mining technology has significant technical advantages in improving mine recovery rate, weakening mine pressure manifestation, reducing tunnel surrounding rock stress and reducing mine gangue discharge. It is an important technical means to achieve green mining in mines. At the same time, the technology of retaining lanes along the goaf has outstanding advantages such as improving coal resource recovery rate, reducing tunnel excavation rate, and alleviating mining and excavation succession difficulties through the successive utilization of lanes. It can also reduce the probability of underground disasters caused by coal pillars.

[0003] In the prior art, the goaf-retaining tunnel is usually filled to isolate the goaf-retaining tunnel from the goaf so as to achieve stability control of the surrounding rock around the goaf-retaining tunnel. The existing method for filling the goaf-retaining tunnel is usually to fill the goaf-retaining tunnel beside the tunnel with conventional high-water materials, or to fill the goaf-retaining tunnel beside the tunnel with concrete materials. Both of the above methods have the problems of complex procedures, large amount of materials invested in constructing the tunnel-side filling body, and high cost. As a result, some mines with complex geological conditions and poor efficiency are often unwilling to use the above technology to fill the goaf-retaining tunnel, which makes it impossible to safely isolate the goaf-retaining tunnel from the goaf, which may lead to the occurrence of safety accidents. Summary of the invention

[0004] The invention provides a method for filling goaf-side tunneling with waste rock, so as to solve the problems in the prior art that the method for filling goaf-side tunneling with waste rock has complicated procedures, requires more materials and has high cost.

[0005] In order to solve the above problems, the present invention provides a method for retaining a goaf with gangue filling, comprising: an advance support step: a plurality of hydraulic pillars are arranged at intervals between the goaf retaining and the goaf along the extension direction of the goaf retaining to support the roadway roof, and then a shielding component is relatively fixed to the hydraulic pillar, the shielding component is used to seal the goaf and temporarily separate the goaf retaining and the goaf; a gangue filling step: a section of the goaf is divided into a first area, a second area and a third area which are arranged adjacent to each other in sequence, the first area, the second area and the third area all extend along the mining direction, and the extension direction is parallel to the extension direction of the goaf retaining; the first area is arranged close to the goaf retaining; the first area is filled with coarse-grained gangue to form a grouting cementing part, and then the second area is filled with fine-grained gangue to form a middle part. The barrier part is then filled with coarse-grained gangue to form a bearing part, with the coarse-grained gangue being larger than the fine-grained gangue; finally, the filled gangue is compacted; reinforcement step: drilling holes on the side of the grouting bonding part facing the goaf, and arranging grouting anchor rods or anchor cables in the drilled multiple holes one by one to reinforce and fix the grouting bonding part; anti-seepage layer spraying step: spraying anti-seepage material on the side of the grouting bonding part facing the goaf and the side of the grouting bonding part facing the unfilled goaf to form a slurry anti-seepage layer on the surface, and the slurry anti-seepage layer is used to prevent the grouting material in the grouting bonding part from seeping out of the surface; grouting step: using grouting anchor rods to grout and reinforce the grouting bonding part, and the middle barrier part prevents the grouting material from penetrating into the bearing part; after the grouting is completed, the isolation between the goaf and the goaf is completed.

[0006] Furthermore, the method for retaining a tunnel along the goaf with waste rock filling also includes a first subsequent processing step: after the grouting step is completed, multiple hydraulic supports are disassembled, and then a foamed concrete material is sprayed on a side of the grouting bonding part facing the tunnel along the goaf to form a concrete layer on the surface.

[0007] Furthermore, the method for retaining a tunnel along the goaf with waste rock filling also includes a second subsequent processing step: after the first subsequent processing step is completed, wait for the concrete layer to solidify and form, and then spray polyurethane material on the surface of the concrete layer to form an anti-weathering coating on the surface of the concrete layer.

[0008] Furthermore, the first subsequent processing step also includes: when the distance between the mining face and the grouting bonding part is within the range of 150m to 180m, dismantling multiple hydraulic supports; controlling the thickness of the concrete layer within the range of 40mm to 100mm; the foamed concrete material includes cement, sand, water and accelerator, wherein the mass ratio of cement to sand is one to two.

[0009] Furthermore, in the advance support step, the shielding assembly includes a gangue-blocking metal mesh and a polyester fiber cloth; the gangue-blocking metal mesh is detachably fixedly connected to the hydraulic support by fasteners, and is used to block gangue; the polyester fiber cloth is fixed to the surface of the gangue-blocking metal mesh by wire binding, and is used to seal the gangue-blocking metal mesh; wherein the gangue-blocking metal mesh and the polyester fiber cloth extend along the extension direction of the goaf-retained tunnel respectively; the grid of the gangue-blocking metal mesh is square, and the side length is less than or equal to 45 mm; and / or, in the advance support step, multiple hydraulic supports are arranged at equal intervals with a spacing of no more than 0.6 m.

[0010] Furthermore, in the gangue filling step, the thickness of the grouting bonding part is 1.5m~2.0m; the thickness of the middle barrier part is not less than 0.5m; the coarse particle size is 20mm~40mm; the fine particle size is 5mm~10mm; and / or, in the gangue filling step, the filling hydraulic support used to support the goaf during mining is moved along the mining direction to form a blank area to be filled in the goaf, and the blank area to be filled is divided into a first area, a second area and a third area; then the first area, the second area and the third area are filled with gangue in turn by a filling scraper conveyor; wherein, when the filling scraper conveyor is filling, after a certain amount of gangue is unloaded from the previous unloading hole on the filling scraper conveyor, the next unloading hole is opened for unloading, and the gangue unloaded from the previous unloading hole is immediately compacted.

[0011] Furthermore, the reinforcement step also includes: drilling holes at equal intervals of 3m to 5m on the side of the grouting bonding part facing the gob-side tunnel retention, and reinforcing and fixing the grouting bonding part using W-shaped steel belts and support beams in conjunction with anchor cables; wherein the W-shaped steel belts and support beams are cross-arranged, the W-shaped steel belts are vertically arranged, and the support beams are horizontally arranged; at the cross-intersection position, the anchor cables pass through the W-shaped steel belts and support beams, and extend into the bearing part for fixation; the grouting holes of the grouting anchor rods extend into the grouting bonding part.

[0012] Furthermore, in the reinforcement step: a plurality of grouting anchors are arranged horizontally in rows and vertically in columns to form an anchor matrix, in a row of the anchor matrix, the spacing between two adjacent grouting anchors is not greater than 750 mm, and in a column of the anchor matrix, the spacing between two adjacent grouting anchors is not greater than 550 mm; the inner diameter of the grouting anchor is greater than 20 mm, and the axial length is 1200 mm to 1800 mm; and / or, in the reinforcement step: a plurality of anchor cables are arranged horizontally in rows and vertically in columns to form an anchor cable matrix, in a row of the anchor cable matrix, the spacing between two adjacent anchor cables is not greater than 800 mm, and in a column of the anchor cable matrix, the spacing between two adjacent anchor cables is not greater than 600 mm; the outer diameter of the anchor cable is greater than 22 mm, and the axial length is 2400 mm to 3000 mm.

[0013] Furthermore, in the anti-seepage layer spraying step, the anti-seepage material includes cement, fly ash, silica fume, polypropylene fiber and composite inorganic chemical foaming agent.

[0014] Furthermore, in the grouting step, the grouting materials include water, silicate cement, grouting soil admixture and grouting curing agent; wherein the number of silicate cement is not less than 325.

[0015] Applying the technical solution of the present invention, the present invention provides a method for retaining a goaf with waste rock filling, comprising: an advance support step: arranging a plurality of hydraulic pillars at intervals between the goaf retaining and the goaf along the extension direction of the goaf retaining to support the roadway roof, and then fixing a shielding component to the hydraulic pillars relatively, the shielding component being used to seal the goaf and temporarily separate the goaf retaining and the goaf; a waste rock filling step: dividing a section of the goaf into a first area, a second area and a third area which are arranged adjacent to each other in sequence, the first area, the second area and the third area all extending along the mining direction, and the extension direction is parallel to the extension direction of the goaf retaining; the first area is arranged close to the goaf retaining; filling the first area with coarse-grained waste rock to form a grouting cementing part, and then filling the second area with fine-grained waste rock to form a medium-grained waste rock. The barrier part is then filled with coarse-grained gangue to form a bearing part, with the coarse-grained gangue being larger than the fine-grained gangue; finally, the filled gangue is compacted; reinforcement step: drilling holes on the side of the grouting bonding part facing the goaf-retained tunnel, and arranging grouting anchor rods or anchor cables in the drilled multiple holes one by one to reinforce and fix the grouting bonding part; anti-seepage layer spraying step: spraying anti-seepage material on the side of the grouting bonding part facing the goaf-retained tunnel and the side of the grouting bonding part facing the unfilled goaf to form a slurry anti-seepage layer on the surface, and the slurry anti-seepage layer is used to prevent the grouting material in the grouting bonding part from seeping out of the surface; grouting step: using grouting anchor rods to grout the grouting bonding part for grouting reinforcement, and the middle barrier part prevents the grouting material from penetrating into the bearing part; after the grouting is completed, the isolation between the goaf-retained tunnel and the goaf is completed.

[0016] The present invention realizes a temporary separation between the goaf and the goaf by arranging an advance support step, thereby ensuring the safety of subsequent gangue filling; in the gangue filling step, different areas are filled and compacted by using gangue of different particle sizes, thereby ensuring the reliable forming of the grouting bonding part, the middle barrier part and the bearing part, and the middle barrier part containing fine-grained gangue can reliably prevent the grouting material from penetrating into the bearing part, thereby avoiding the waste of grouting material and saving costs; in addition, the use of gangue for filling not only realizes waste utilization and gangue treatment, but also effectively saves costs; by arranging a reinforcement step, the reliability of the grouting bonding part is guaranteed, which can not only ensure the smooth grouting of the subsequent grouting bonding part, but also avoid the dumping accident of the grouting bonding part; by arranging a waterproof layer spraying step, a slurry waterproofing can be formed on the outer surface of the grouting bonding part layer, thereby preventing the grouting material from seeping out from the surface of the grouting bonding part, thereby further saving the grouting material and the material cost; the method of the present invention can fill the goaf and the goaf along the goaf with gangue and grouting and bonding, to construct a gangue bonding filling body including a grouting bonding part, a middle barrier part and a bearing part to isolate the goaf and the goaf along the goaf, thereby achieving efficient utilization of gangue and improving the surrounding rock stability of the goaf along the goaf; the method of the present invention simplifies the filling process of the goaf along the goaf, improves the filling efficiency of the goaf along the goaf, and at the same time uses gangue waste as the filling material of the goaf along the goaf, without the need to purchase other filling materials additionally, thereby reducing the filling cost and alleviating the workload of filling the goaf along the goaf; therefore, the present invention solves the problems of complex procedures, large amounts of materials and high costs in the prior art for filling the goaf along the goaf, and is suitable for large-scale promotion and use. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The drawings constituting a part of the present application are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0018] Figure 1 A method flow chart showing some steps of a method for retaining a goaf-side entry with gangue filling provided by an embodiment of the present invention;

[0019] Figure 2 A partial structural schematic diagram of a goaf-side entry retaining with gangue filling provided by an embodiment of the present invention is shown in a top-down view;

[0020] Figure 3 A partial structural schematic diagram of grouting performed at a top view angle provided by an embodiment of the present invention is shown;

[0021] Figure 4 A partial structural schematic diagram of the embodiment of the present invention when performing early support at a side view angle is shown;

[0022] Figure 5 A partial structural schematic diagram of grouting performed at a side view angle provided by an embodiment of the present invention is shown.

[0023] The above drawings include the following reference numerals:

[0024] 10. Leave lanes along the empty space;

[0025] 20. Goaf; 21. Grouting and bonding part; 22. Middle barrier part; 23. Bearing part;

[0026] 30. Hydraulic prop;

[0027] 40. Shielding assembly; 41. Metal mesh for blocking gangue; 42. Polyester fiber cloth; 43. W-shaped steel belt; 44. Support beam; 45. Steel pallet;

[0028] 50. Grouting anchor;

[0029] 60. Anchor cable;

[0030] 70. Slurry anti-seepage layer;

[0031] 80. Filling scraper conveyor;

[0032] 90. Fill the hydraulic support. DETAILED DESCRIPTION

[0033] 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, rather than all the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is by no means intended to limit the present invention and its application or use. 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.

[0034] like Figures 1 to 5As shown, an embodiment of the present invention provides a method for retaining a goaf with gangue filling, comprising: an advance support step: a plurality of hydraulic pillars 30 are arranged at intervals between the goaf retaining goaf 10 and the goaf 20 along the extension direction of the goaf retaining goaf 10 to support the roadway roof, and then a shielding assembly 40 is relatively fixed to the hydraulic pillar 30, the shielding assembly 40 is used to seal the goaf 20, and temporarily separate the goaf retaining goaf 10 from the goaf 20; a gangue filling step: a section of the goaf 20 is divided into a first area, a second area and a third area which are arranged adjacent to each other in sequence, the first area, the second area and the third area all extend along the mining direction, and the extension direction is parallel to the extension direction of the goaf retaining goaf 10; the first area is arranged close to the goaf retaining goaf 10; the first area is filled with coarse-grained gangue to form a grouting bonding part 21, and then the second area is filled with fine-grained gangue to form a middle barrier part 22, and then Then, the third area is filled with coarse-grained waste rock to form a bearing portion 23, wherein the coarse-grained waste rock is larger than the fine-grained waste rock; finally, the filled waste rock is compacted; reinforcement step: holes are drilled on one side of the grouting bonding portion 21 facing the gob-side tunnel 10, and grouting anchor rods 50 or anchor cables 60 are arranged one by one in the drilled multiple holes to reinforce and fix the grouting bonding portion 21; anti-seepage layer spraying step: the grouting bonding portion 21 is sprayed on one side of the grouting bonding portion 21 facing the gob-side tunnel 10 and the grouting bonding portion 21; The bonding part 21 is sprayed with anti-seepage material on one side facing the unfilled goaf 20 to form a slurry anti-seepage layer 70 on the surface, and the slurry anti-seepage layer 70 is used to prevent the grouting material in the grouting bonding part 21 from seeping out of the surface; grouting step: the grouting bonding part 21 is grouting reinforced by grouting anchor rods 50, and the middle barrier part 22 prevents the grouting material from penetrating into the bearing part 23; after the grouting is completed, the isolation between the goaf 20 and the goaf is completed.

[0035] The present invention realizes a temporary interval between the goaf-side tunnel 10 and the goaf 20 by arranging an advance support step, thereby ensuring the safety of subsequent gangue filling; in the gangue filling step, by using gangue of different particle sizes to fill different areas and compact them respectively, it not only ensures the reliable forming of the grouting bonding part 21, the middle barrier part 22 and the bearing part 23, but also makes the middle barrier part containing fine-grained gangue reliably prevent the grouting material from penetrating into the bearing part 23, thereby avoiding the waste of grouting material and saving costs; in addition, the use of gangue for filling not only realizes waste utilization and gangue treatment, but also effectively saves costs; by arranging a reinforcement step, the reliability of the grouting bonding part 21 is guaranteed, which can not only ensure the smooth grouting of the subsequent grouting bonding part 21, but also avoid the dumping accident of the grouting bonding part 21; by arranging an anti-seepage layer spraying step, a slurry anti-seepage layer 70 can be formed on the outer surface of the grouting bonding part 21. The method avoids the grouting material from seeping out from the surface of the grouting bonding part 21, thereby further saving the grouting material and the material cost. The method of the present invention can fill the goaf 20 and the goaf-side tunnel 10 with gangue and grouting and bonding, thereby constructing a gangue bonding filling body including a grouting bonding part 21, a middle barrier part 22 and a bearing part 23 to isolate the goaf 20 and the goaf-side tunnel 10, thereby achieving efficient utilization of gangue and improving the surrounding rock stability of the goaf-side tunnel 10. The method of the present invention simplifies the filling process of the goaf-side tunnel 10 and improves the filling efficiency of the goaf-side tunnel 10. At the same time, gangue waste is used as the filling material of the goaf-side tunnel 10, and there is no need to purchase other filling materials additionally, which reduces the filling cost and reduces the workload of filling the goaf-side tunnel 10. Therefore, the present invention solves the problems of complex procedures, large amounts of materials and high costs in the prior art for filling goaf-side tunnels, and is suitable for large-scale promotion and use.

[0036] Specifically, the method for retaining a tunnel along the goaf with waste rock filling also includes a first subsequent processing step: after the grouting step is completed, the plurality of hydraulic props 30 are disassembled, and then the foamed concrete material is sprayed on one side of the grouting bonding part 21 facing the tunnel along the goaf 10 to form a concrete layer on the surface.

[0037] By spraying the foamed concrete material on the side of the grouting bonding part 21 facing the gob retaining tunnel 10 , a concrete layer can be formed on the surface thereof, thereby ensuring the surface strength and sealing of the grouting bonding part 21 .

[0038] Specifically, the gangue filling gob-side tunnel retaining method also includes a second subsequent processing step: after the first subsequent processing step is completed, wait for the concrete layer to solidify and form, and then spray polyurethane material on the surface of the concrete layer to form an anti-weathering coating on the surface of the concrete layer.

[0039] By spraying polyurethane material on the surface of the concrete layer, an anti-weathering coating is formed on the surface of the concrete layer, thereby ensuring the weathering resistance and airtightness of the grouting bonding part 21.

[0040] Specifically, the first subsequent processing step also includes: when the distance between the mining face and the grouting bonding part 21 is within the range of 150m to 180m, dismantling multiple hydraulic supports 30; controlling the thickness of the concrete layer within the range of 40mm to 100mm; the foamed concrete material includes cement, sand, water and accelerator, wherein the mass ratio of cement to sand is one to two.

[0041] By dismantling multiple hydraulic supports 30 when the distance between the mining face and the grouting bonding part 21 is within the range of 150m to 180m, the surrounding rock has undergone a pressure release and adjustment process, and its self-stabilizing ability has been enhanced. At this time, the risk of withdrawing the hydraulic supports 30 is low, ensuring safety. At the same time, withdrawing the hydraulic supports 30 can release operating space; by setting the thickness of the concrete layer, the grouting bonding part 21 can be effectively closed and material waste can be avoided.

[0042] It should be noted that: in order to ensure the integrity of the foamed concrete material after spraying, the foamed concrete material contains an appropriate amount of accelerating setting agent, and the accelerating setting agent can be selected from aluminate powder; professional spraying equipment (for example: PZ-5 type spraying equipment) is used when spraying the foamed concrete material, the working pressure is 0.6MPa, and the inner diameter of the pipe for conveying the foamed concrete material is 50mm, so as to ensure the smoothness and reliability of the spraying.

[0043] like Figure 4 and Figure 5 As shown, in the advance support step, the shielding assembly 40 includes a gangue-blocking metal mesh 41 and a polyester fiber cloth 42; the gangue-blocking metal mesh 41 is detachably fixedly connected to the hydraulic support 30 by fasteners, and is used to block gangue; the polyester fiber cloth 42 is fixed to the surface of the gangue-blocking metal mesh 41 by wire binding, and is used to seal the gangue-blocking metal mesh 41; wherein the gangue-blocking metal mesh 41 and the polyester fiber cloth 42 extend along the extension direction of the gob-retained tunnel 10 respectively; the grid of the gangue-blocking metal mesh 41 is square, and the side length is less than or equal to 45 mm; and / or, in the advance support step, multiple hydraulic supports 30 are equidistantly arranged at a spacing of no more than 0.6 m.

[0044] The reason why the grid of the gangue retaining metal mesh 41 is set to be square and the side length is less than or equal to 45 mm is to take into account the size and looseness of the filling gangue, to ensure that the gangue retaining metal mesh 41 can effectively support and reinforce the surrounding rock, and to avoid local stress concentration at the same time; the reason why the hydraulic pillars 30 are arranged at equal intervals with a spacing of no more than 0.6m is to take into account the surrounding rock pressure distribution and economy. Such an interval setting can make the hydraulic pillars 30 evenly distribute the load, improve the stability and support effect of the tunnel, and at the same time, reduce construction costs.

[0045] like Figure 2 and Figure 3 As shown, in the gangue filling step, the thickness of the grouting bonding part 21 is 1.5m~2.0m; the thickness of the middle barrier part 22 is not less than 0.5m; the coarse particle size is 20mm~40mm; the fine particle size is 5mm~10mm; and / or, in the gangue filling step, the filling hydraulic support 90 used to support the goaf 20 during mining is moved along the mining direction to form a blank area to be filled in the goaf 20, and the blank area to be filled is divided into a first area, a second area and a third area; then the first area, the second area and the third area are filled with gangue in turn by the filling scraper conveyor 80; wherein, when the filling scraper conveyor 80 is filling, after a certain amount of gangue is discharged from the previous unloading hole of the filling scraper conveyor 80, the next unloading hole is opened for unloading, and the gangue discharged from the previous unloading hole is immediately compacted.

[0046] By setting a fine particle size, the barrier effect of the middle barrier 22 on the grouting material is ensured; by setting the working process of the filling scraper conveyor 80 and removing the filling hydraulic support 90, the overall working efficiency of the waste rock filling method along the goaf can be further improved.

[0047] like Figure 5 As shown, the reinforcement step also includes: drilling holes equidistantly at intervals of 3m to 5m on the side of the grouting and bonding part 21 facing the gob-side tunnel 10, and reinforcing and fixing the grouting and bonding part 21 by using a W-shaped steel belt 43 and a support beam 44 in cooperation with an anchor cable 60; wherein the W-shaped steel belt 43 and the support beam 44 are cross-arranged, the W-shaped steel belt 43 is vertically arranged, and the support beam 44 is horizontally arranged; at the cross-intersection position, the anchor cable 60 passes through the W-shaped steel belt 43 and the support beam 44, and extends into the bearing part 23 for fixation; the grouting hole of the grouting anchor rod 50 extends into the grouting and bonding part 21.

[0048] By setting the drilling spacing, the grouting effect and the anchor fixing effect are guaranteed; by using the W-shaped steel belt 43 and the support beam 44 in conjunction with the anchor 60 to reinforce and fix the grouting bonding part 21, the low-cost and easily available structure in the tunnel is used to achieve reliable fixation of the grouting bonding part 21, further reducing the cost.

[0049] like Figure 5 As shown, in the reinforcement step: a plurality of grouting anchor rods 50 are arranged horizontally in rows and vertically in columns to form an anchor rod matrix, in a row of the anchor rod matrix, the spacing between two adjacent grouting anchor rods 50 is not greater than 750 mm, and in a column of the anchor rod matrix, the spacing between two adjacent grouting anchor rods 50 is not greater than 550 mm; the inner diameter of the grouting anchor rod 50 is greater than 20 mm, and the axial length is 1200 mm to 1800 mm; and / or, in the reinforcement step: a plurality of anchor cables 60 are arranged horizontally in rows and vertically in columns to form an anchor cable matrix, in a row of the anchor cable matrix, the spacing between two adjacent anchor cables 60 is not greater than 800 mm, and in a column of the anchor cable matrix, the spacing between two adjacent anchor cables 60 is not greater than 600 mm; the outer diameter of the anchor cable 60 is greater than 22 mm, and the axial length is 2400 mm to 3000 mm.

[0050] By setting up the anchor rod matrix and the anchor cable matrix, the grouting effect and reinforcement effect are guaranteed.

[0051] In a specific embodiment of the present invention, each anchor cable 60 is lengthened and anchored by using two sections of Z2360 and one section of K2360 resin rolls to ensure that the anchor cable 60 can be driven into the bearing portion 23 .

[0052] like Figure 5 As shown, in another specific embodiment of the present invention, the shielding assembly 40 further includes a steel tray 45, which is connected to the W-shaped steel belt 43 and / or the support beam 44 to support the anchor cable 60 when the anchor cable 60 is installed.

[0053] Optionally, in the anti-seepage layer spraying step, the anti-seepage material includes cement, fly ash, silica fume, polypropylene fiber and a composite inorganic chemical foaming agent.

[0054] By setting the specific composition of the anti-seepage material, the reliable anti-seepage of the slurry anti-seepage layer 70 is ensured and the cost is effectively reduced.

[0055] Optionally, in the grouting step, the grouting materials include water, silicate cement, grouting soil admixture and grouting curing agent; wherein the number of silicate cement is not less than 325.

[0056] By setting the specific composition of the grouting material, the grouting reinforcement effect is ensured to be reliable and the cost is effectively reduced.

[0057] It should be noted that the cement number 325 is an existing method of indicating cement strength grade, which is usually used to describe cement performance; this number indicates the compressive strength of cement. Specifically, 325 means that after a 28-day curing period, the compressive strength of cement is 32.5 megapascals (MPa); cement has different strength grades, numbered 325, 425, 525, etc.; these numbers indicate the compressive strength of cement after a 28-day curing period, and the higher the strength grade, the greater the load-bearing capacity of the cement; therefore, the cement number is a comprehensive representation of cement type, strength grade, production process and other information, which helps users choose the right cement according to actual needs; when using cement, you should carefully check the cement number and related instructions to ensure that you choose the right cement product.

[0058] The specific working process and principle of a specific embodiment of the present invention are now described in detail as follows:

[0059] Step 1: closely following the coal mining working face, during the advancement of the working face, a hydraulic support 30 is set up on one side of the gob-side tunnel 10 close to the gob 20, and a gangue-blocking metal mesh 41 and a polyester fiber cloth 42 are hung in sequence to achieve temporary gangue blocking and seal the gob 20;

[0060] Step 2: The filling scraper conveyor 80 of the filling hydraulic support 90 is used to fill the gangue of different particle sizes from the tail to the head direction. First, the coarse-grained gangue is used to fill the first area to form the grouting bonding part 21. After filling to the set width, the fine-grained gangue is then used to fill the second area to form the middle barrier part 22; finally, the coarse-grained gangue is used to fill to form the bearing part 23;

[0061] Step 3: After the gangue filling is advanced a certain distance along the direction of the coal mining face, i.e., the mining direction, a borehole is drilled on the grouting bonding part 21 toward the goaf 20, a grouting anchor rod 50 is arranged, and a W-shaped steel belt 43 and a ladder beam (i.e., a support beam 44) are installed by using an anchor cable 60 for joint reinforcement support;

[0062] Step 4: Spray foamed concrete on the outer surface of the grouting bonding part 21 to form a slurry impermeable layer 70, and then use the grouting anchor rod 50 to grout the grouting bonding part 21 in the filling gangue to construct a gangue bonding roadside filling body;

[0063] Step 5: After the working face has advanced a certain distance ahead of the reserved lane section, the hydraulic support 30 is removed, and foamed concrete is sprayed on the surface of the gangue cemented lane side filling body in the lane. After the concrete solidifies, a polyurethane anti-weathering coating is sprayed on the outside of the foamed concrete spray layer.

[0064] In the first step, the hydraulic prop 30 is connected to the gangue retaining metal mesh 41 by fasteners, and the polyester fiber cloth 42 is tied to the inner side of the metal mesh by iron wire;

[0065] In the second step, the gangue-bonded roadside filling body is formed after grouting and bonding along the side of the gob-retained roadway 10, which is equivalent to the roadside wall of the gob-retained roadway 10. The width of the gangue-bonded roadside filling body is designed to be 1.5-2.0m to ensure the stability of the filling wall during long-term use; the middle barrier part 22 is formed by filling fine-grained gangue to a certain width to prevent the slurry from diffusing to the distant bearing part 23 during subsequent grouting. The width of the barrier part 22 is 0.5m, which ensures the barrier performance and economy at the same time; in the second step, the grouting bonding part 21 and the bearing part 23 are filled with large-diameter gangue, and the designed gangue particle size is 20-40mm to provide better mechanical strength and stability; the middle barrier part 22 is filled with small-diameter gangue, and the designed gangue particle size is 5-10mm to form a dense filling layer to effectively block the diffusion of slurry;

[0066] In the third step, the W-shaped steel strip 43 and the ladder beam are arranged crosswise outside the gangue retaining metal mesh 41 , and are connected at the intersection of the W-shaped steel strip 43 and the ladder beam by an anchor cable 60 . The anchor cable 60 is driven into the bearing portion 23 . The grouting anchor rod 50 is driven into the deep of the grouting bonding part 21 through the gangue retaining metal mesh 41; in the third step, the distance of the gangue in the goaf 20 after filling is compacted to 3 to 5 meters to avoid affecting the filling quality; the spacing between multiple grouting anchor rods 50 is 550mm×750mm, ensuring that the filling wall is fully supported and controlling the cost, and the specification is ∮20mm×1200~1800mm, ensuring that the grouting anchor rod 50 can be driven into the deep of the grouting bonding part 21; the spacing between multiple anchor cables 60 is 600mm×800mm, and the matching specification is ∮22mm×2400~3000mm to match the installation specifications of the W-shaped steel belt 43 and the ladder beam. Each anchor cable 60 is extended and anchored with 2 sections of Z2360 and 1 section of K2360 resin medicine rolls to ensure that the anchor cable 60 can be driven into the bearing part 23.

[0067] In summary, the present invention provides a method for retaining a goaf with gangue filling. The present invention realizes a temporary interval between the goaf retaining goaf 10 and the goaf 20 by setting an advance support step, thereby ensuring the safety of subsequent gangue filling; in the gangue filling step, by using gangue of different particle sizes to fill different areas and compact them, it not only ensures the reliable forming of the grouting bonding part 21, the middle barrier part 22 and the bearing part 23, but also makes the middle barrier part containing fine-grained gangue can be The grouting material is reliably prevented from penetrating into the bearing part 23, thereby avoiding the waste of grouting material and saving costs. In addition, the use of gangue for filling not only realizes waste utilization and gangue treatment, but also effectively saves costs. By setting the reinforcement step, the reliability of the grouting bonding part 21 is guaranteed, which can not only ensure the smooth grouting of the subsequent grouting bonding part 21, but also avoid the dumping accident of the grouting bonding part 21. By setting the anti-seepage layer spraying step, the outer surface of the grouting bonding part 21 is A slurry anti-seepage layer 70 can be formed, thereby preventing the grouting material from seeping out from the surface of the grouting bonding part 21, thereby further saving the grouting material and saving the material cost; the method of the present invention can fill the goaf 20 and the goaf-side tunnel 10 with gangue and grouting and bonding, thereby constructing a gangue bonding filling body including the grouting bonding part 21, the middle barrier part 22 and the bearing part 23 to isolate the goaf 20 and the goaf-side tunnel 10, thereby achieving efficient utilization of gangue and improving the goaf-side tunnel 10. The surrounding rock stability of the tunnel 10; the method of the present invention simplifies the filling process of the tunnel 10 along the goaf, improves the filling efficiency of the tunnel 10 along the goaf, and at the same time uses waste rock as the filling material of the tunnel 10 along the goaf, without the need to purchase other filling materials, thereby reducing the filling cost and alleviating the workload of filling the tunnel 10 along the goaf; therefore, the present invention solves the problems in the prior art of the method of filling the tunnel along the goaf that the process is complicated, more materials are required and the cost is high, and is suitable for large-scale promotion and use.

[0068] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0069] Unless otherwise specifically stated, the relative arrangement, numerical expressions and numerical values ​​of the parts and steps set forth in these embodiments do not limit the scope of the present invention. Meanwhile, it should be understood that, for ease of description, the sizes of the various parts shown in the accompanying drawings are not drawn according to the actual proportional relationship. The technology, method and equipment known to those of ordinary skill in the relevant art may not be discussed in detail, but in appropriate cases, the technology, method and equipment should be considered as a part of the specification. In all examples shown and discussed here, any specific value should be interpreted as being merely exemplary, rather than as a limitation. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters represent similar items in the following drawings, and therefore, once a certain item is defined in an accompanying drawing, it does not need to be further discussed in subsequent drawings.

[0070] In the description of the present invention, it is necessary to understand that the directions or positional relationships indicated by directional words such as "front, back, up, down, left, right", "lateral, vertical, perpendicular, horizontal" and "top, bottom" are usually based on the directions or positional relationships shown in the drawings. They are only for the convenience of describing the present invention and simplifying the description. Unless otherwise specified, these directional words do not indicate or imply that the devices or elements referred to must have a specific direction or be constructed and operated in a specific direction. Therefore, they cannot be understood as limiting the scope of protection of the present invention. The directional words "inside and outside" refer to the inside and outside relative to the contours of each component itself.

[0071] For ease of description, spatially relative terms such as "above", "above", "on the upper surface of", "above", etc. may be used here to describe the spatial positional relationship between a device or feature and other devices or features as shown in the figure. It should be understood that spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation described in the figure. For example, if the device in the accompanying drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "below other devices or structures". Thus, the exemplary term "above" can include both "above" and "below". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatially relative descriptions used here are interpreted accordingly.

[0072] In addition, it should be noted that the use of terms such as "first" and "second" to limit components is only for the convenience of distinguishing the corresponding components. If not otherwise stated, the above terms have no special meaning and therefore cannot be understood as limiting the scope of protection of the present invention.

[0073] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for retaining goaf-side entry with gangue filling, characterized in that: include: Advance support step: a plurality of hydraulic pillars (30) are arranged at intervals between the gob-side tunnel (10) and the goaf (20) along the extension direction of the gob-side tunnel (10) to support the tunnel roof, and then a shielding assembly (40) is fixed relatively to the hydraulic pillar (30), wherein the shielding assembly (40) is used to seal the goaf (20) and temporarily separate the gob-side tunnel (10) from the goaf (20); Gangue filling step: a section of the goaf (20) is divided into a first area, a second area and a third area which are arranged adjacent to each other in sequence, wherein the first area, the second area and the third area all extend in the mining direction, and the extension direction is parallel to the extension direction of the goaf-side tunnel (10); the first area is arranged close to the goaf-side tunnel (10); the first area is filled with gangue of coarse particle size to form a grouting bonding part (21), and then the second area is filled with gangue of fine particle size to form a middle barrier part (22), and then the third area is filled with gangue of coarse particle size to form a bearing part (23), wherein the coarse particle size is larger than the fine particle size; finally, the filled gangue is compacted; Reinforcement step: drilling holes on one side of the grouting bonding part (21) facing the gob-side tunnel retaining (10), and arranging grouting anchor rods (50) or anchor cables (60) one by one in the drilled holes to reinforce and fix the grouting bonding part (21); Anti-seepage layer spraying step: spraying anti-seepage material on one side of the grouting bonding part (21) facing the goaf-side tunneling (10) and one side of the grouting bonding part (21) facing the unfilled goaf (20) to form a slurry anti-seepage layer (70) on the surface, wherein the slurry anti-seepage layer (70) is used to prevent the grouting material in the grouting bonding part (21) from seeping out of the surface; Grouting step: using the grouting anchor rod (50) to perform grouting reinforcement on the grouting bonding part (21), and the middle barrier part (22) prevents the grouting material from penetrating into the bearing part (23); after the grouting is completed, the isolation between the goaf-side tunnel (10) and the goaf (20) is completed.

2. The method for retaining gob-side entry with gangue filling according to claim 1, characterized in that: The method for retaining a goaf with waste rock filling also includes a first subsequent processing step: after the grouting step is completed, the plurality of hydraulic props (30) are disassembled, and then a foamed concrete material is sprayed on a side of the grouting bonding portion (21) facing the goaf retaining goaf (10) to form a concrete layer on the surface.

3. The method for retaining gob-side entry with gangue filling according to claim 2, characterized in that: The gangue filling gob-side tunnel retaining method also includes a second subsequent processing step: after the first subsequent processing step is completed, waiting for the concrete layer to solidify and then spraying polyurethane material on the surface of the concrete layer to form an anti-weathering coating on the surface of the concrete layer.

4. The method for retaining gob-side entry with gangue filling according to claim 2, characterized in that: The first subsequent processing step also includes: when the distance between the mining face and the grouting bonding part (21) is within the range of 150m to 180m, dismantling the plurality of hydraulic supports (30); controlling the thickness of the concrete layer within the range of 40mm to 100mm; the foamed concrete material includes cement, sand, water and an accelerating setting agent, wherein the mass ratio of the cement to the sand is one to two.

5. The method for retaining gob-side entry with gangue filling according to claim 1, characterized in that: In the advance support step, the shielding assembly (40) comprises a gangue-blocking metal mesh (41) and a polyester fiber cloth (42); the gangue-blocking metal mesh (41) is detachably fixedly connected to the hydraulic support (30) by a fastener, and is used to block gangue; the polyester fiber cloth (42) is fixed to the surface of the gangue-blocking metal mesh (41) by iron wire binding, and is used to seal the gangue-blocking metal mesh (41); wherein the gangue-blocking metal mesh (41) and the polyester fiber cloth (42) extend respectively along the extension direction of the gob-retained tunnel (10); the mesh of the gangue-blocking metal mesh (41) is square, and the side length is less than or equal to 45 mm; And / or, in the advance support step, the plurality of hydraulic props (30) are arranged at equal intervals with a spacing of no more than 0.6 m.

6. The method for retaining gob-side entry with gangue filling according to claim 1, characterized in that: In the gangue filling step, the thickness of the grouting bonding part (21) is 1.5m-2.0m; the thickness of the middle barrier part (22) is not less than 0.5m; the coarse particle size is 20mm-40mm; the fine particle size is 5mm-10mm; and / or, in the gangue filling step, a filling hydraulic support (90) used for supporting the goaf (20) during mining is moved along the mining direction, so that the goaf (20) forms a blank area to be filled, and the blank area to be filled is divided into the first area, the second area and the third area; Then, the first area, the second area and the third area are filled with gangue in sequence by using a filling scraper conveyor (80); wherein, when the filling scraper conveyor (80) is filling, after a certain amount of gangue is discharged from the previous discharge hole of the filling scraper conveyor (80), the next discharge hole is opened for discharge, and the gangue discharged from the previous discharge hole is then compacted.

7. The method for retaining gob-side entry with gangue filling according to claim 1, characterized in that: The reinforcement step also includes: drilling holes at equal intervals of 3m to 5m on a side of the grouting and bonding part (21) facing the gob-side tunnel retaining (10), and reinforcing and fixing the grouting and bonding part (21) by using a W-shaped steel belt (43) and a support beam (44) in cooperation with the anchor cable (60); wherein the W-shaped steel belt (43) and the support beam (44) are arranged in a cross-shaped manner, the W-shaped steel belt (43) is arranged vertically, and the support beam (44) is arranged horizontally; at the cross-shaped position, the anchor cable (60) passes through the W-shaped steel belt (43) and the support beam (44), and extends into the bearing part (23) for fixation; and the grouting hole of the grouting anchor rod (50) extends into the grouting and bonding part (21).

8. The method for retaining gob-side entry with gangue filling according to claim 1, characterized in that: In the reinforcement step: a plurality of the grouting anchor rods (50) are arranged horizontally in rows and vertically in columns to form an anchor rod matrix; in a row of the anchor rod matrix, the distance between two adjacent grouting anchor rods (50) is no greater than 750 mm; in a column of the anchor rod matrix, the distance between two adjacent grouting anchor rods (50) is no greater than 550 mm; the inner diameter of the grouting anchor rod (50) is greater than 20 mm, and the axial length is 1200 mm to 1800 mm; And / or, in the reinforcement step: a plurality of the anchor cables (60) are arranged horizontally in rows and vertically in columns to form an anchor cable matrix, in a row of the anchor cable matrix, the distance between two adjacent anchor cables (60) is not greater than 800 mm, and in a column of the anchor cable matrix, the distance between two adjacent anchor cables (60) is not greater than 600 mm; the outer diameter of the anchor cable (60) is greater than 22 mm, and the axial length is 2400 mm to 3000 mm.

9. The method for retaining gob-side entry with waste rock filling according to claim 1, characterized in that: In the anti-seepage layer spraying step, the anti-seepage material includes cement, fly ash, silica fume, polypropylene fiber and composite inorganic chemical foaming agent.

10. The method for retaining gob-side entry with waste rock filling according to claim 1, characterized in that: In the grouting step, the grouting materials include water, silicate cement, grouting soil admixture and grouting curing agent; wherein the serial number of the silicate cement is not less than 325.

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