Roof fall filling structure for high-gas area of coal mine

Abstract

The utility model provides a coal mine high-gas area roof caving filling structure, which belongs to the technical field of coal mine support, and adopts a guniting layer, a steel beam layer and a wood plate layer as the support of the top-caving area filler, flexible mold bags seal the two ends of the top-caving area, and after the top-caving area filler fills the top-caving area, a gas accumulation area is eliminated, and the gas accumulation area is prevented from being blocked. The top plate supporting strength of the top-caving area can completely reach the anchor net supporting strength, and the top plate safety of the top-caving area is ensured.

Description

Technical Field

[0001] The utility model belongs to the technical field of coal mine support, and particularly discloses a roof-fall filling structure for a high-gas area in a coal mine. Background Art

[0002] When tunnels pass through fault zones, they can experience excessive height and caving due to factors such as coal seam misalignment, undercover excavation, and coal fragmentation, creating high-risk areas. These areas present hidden dangers such as gas accumulation and roof collapse, seriously threatening the safe operation of the tunnels and must be addressed. Utility Model Content

[0003] The utility model provides a roof-fall filling structure for a high-gas area in a coal mine, which can fill the high-gas area and strengthen support to prevent gas accumulation and roof-fall threats in the high-gas area.

[0004] The above-mentioned coal mine high gas area roof filling structure includes a shotcrete layer, a steel beam layer, a wooden board layer, a duct cloth, a flexible mold bag, a grouting pipe and filling materials in the high gas area; the steel beam layer is arranged below the high gas area, and the height of the steel beam layer is the same as the normal height of the tunnel. The steel beam layer includes multiple rows of hanging steel beams hung at equal intervals along the tunnel direction, the length direction of the hanging steel beams is perpendicular to the tunnel direction, and the two ends of the hanging steel beams are close to the coal seam; the wooden board layer includes multiple rows of wooden boards connected in sequence, and the wooden boards are fixedly laid on the hanging steel beams and perpendicular to the hanging steel beams; the duct cloth is fixedly laid on the wooden board layer, and the duct The edge of the cloth is fixedly connected to the coal seam; the shotcrete layer is arranged below the steel beam layer and the wooden board layer, and the edge of the shotcrete layer is connected to the roof of the normal area of the tunnel; the soft mold bags are arranged at both ends of the high-risk area along the tunnel direction, above the air duct cloth, and the soft mold bags are filled with soft mold bag fillers to connect the surface of the soft mold bags with the roof of the high-risk area; multiple groups of grouting pipes pass through the shotcrete layer, steel beam layer, wooden board layer, and air duct cloth and are inserted into the space between the roof of the high-risk area and the soft mold bags; the fillers in the high-risk area are filled into the space enclosed by the air duct cloth, the roof of the high-risk area and the soft mold bags through the grouting pipes.

[0005] In the above-mentioned coal mine high-gas area roof-burst filling structure, each row of hanging steel beams includes two π-shaped steels, on which hanging points are welded, and the two ends of the π-shaped steels are fixed to the coal seam by iron wire.

[0006] In the above-mentioned coal mine high-gas area roof filling structure, the wooden boards and π-shaped steel are fixed by compacting and bundling with steel bars, and a metal mesh is laid above the wooden boards. The metal mesh is tightly attached to the steel bars and tied with wire.

[0007] In the roof-fall filling structure in the high-gas area of the above-mentioned coal mine, the air duct cloth is fixedly connected to the coal wall by iron wire.

[0008] In the above-mentioned coal mine high-gas area roof-fall filling structure, two cuffs are provided on the flexible mold bag, and the two cuffs are respectively connected to the air duct and the filling pipe.

[0009] In the above-mentioned coal mine high-gas area roof-fall filling structure, each group of grouting pipes includes a main grouting pipe and a spare grouting pipe.

[0010] In the above-mentioned roof-fall filling structure in the high-gas area of the coal mine, a mesh is laid between the π-shaped steel and the shotcrete layer.

[0011] In the roof-fall filling structure in the high-gas area of the above-mentioned coal mine, the material of the shotcrete layer is a mixture of cement, stone powder and yellow sand. The volume ratio of cement, stone powder and yellow sand is 1:2:2, and the cement strength is C20.

[0012] In the above-mentioned coal mine high-gas area roof fall filling structure, the filling material in the high-gas area is inorganic foaming material.

[0013] Compared with the prior art, the beneficial effects of the present invention are:

[0014] The roof filling structure in the high-gas area of the above-mentioned coal mine adopts a shotcrete layer, a steel beam layer, and a wooden board layer as the support for the filling material in the high-gas area. The flexible mold bag seals the two ends of the high-gas area. After the high-gas area filling material fills the high-gas area, the gas accumulation area is eliminated. The roof support strength of the high-gas area can fully reach the anchor net support strength, ensuring the safety of the roof in the high-gas area. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the specific implementation methods or the description of the prior art. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0016] Figure 1 This is a structural diagram of the roof-fall filling structure in a high-gas area of a coal mine;

[0017] Figure 2 This is the layout diagram of the flexible mold bag;

[0018] Figure 3 A drawing showing the measured data of the high-risk area in Lane 53041.

[0019] In the figure: 1- shotcrete layer; 2- steel beam layer; 3- wood board layer; 4- air duct cloth; 5- flexible mold bag; 5.1- cuff; 6- grouting pipe; 7- high-risk area filling;

[0020] 101-Roof of normal tunnel area; 102-Roof of high-risk area; 103-Flood floor of tunnel. DETAILED DESCRIPTION

[0021] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings of the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the described 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. Unless otherwise defined, the technical terms or scientific terms used herein should be the common meanings understood by people with ordinary skills in the field to which the present invention belongs.

[0022] The words "first", "second" and similar terms used in the specification and claims of this utility model patent application do not indicate any order, quantity or importance, but are only used to distinguish different components. Words such as "include" or "comprises" mean that the elements or objects appearing before the word include the elements or objects listed after the word and their equivalents, without excluding other elements or objects.

[0023] Example 1

[0024] This embodiment provides a roof-burst filling structure for high-gas areas in coal mines, comprising a shotcrete layer 1, a steel beam layer 2, a wood board layer 3, a wind tube cloth 4, a flexible mold bag 5, a grouting pipe 6 and a high-gas area filling material 7.

[0025] The steel beam layer 2 is arranged below the high-risk area. The height of the steel beam layer 2 is the same as the normal height of the tunnel. The steel beam layer 2 includes multiple rows of hanging steel beams hung at equal intervals along the tunnel direction. The length direction of the hanging steel beams is perpendicular to the tunnel direction, and the two ends of the hanging steel beams are close to the coal seam; specifically, each row of hanging steel beams includes two π-shaped steels, and the π-shaped steels are welded with hanging points. The two ends of the π-shaped steels are fixed to the coal seam by iron wire.

[0026] The wooden board layer 3 includes multiple rows of wooden boards connected in sequence, which are fixedly laid on the hanging steel beams and perpendicular to the hanging steel beams; specifically, the wooden boards and the π-shaped steel are fixed by compacting and bundling with steel bars, and a metal mesh is laid above the wooden boards, which is tightly attached to the steel bars and tied with wire.

[0027] The air duct cloth 4 is fixedly laid on the wooden board layer 3, and the edge of the air duct cloth 4 is fixedly connected to the coal seam; specifically, the air duct cloth 4 is fixedly connected to the coal seam through iron wire.

[0028] The shotcrete layer 1 is placed beneath the steel beam layer 2 and the wood plank layer 3, with its edge contacting the normal tunnel roof 101. To facilitate adhesion of the shotcrete layer 1, a mesh layer can be laid beneath the π-shaped beams before the shotcrete is applied. The shotcrete layer 1 is made from a mixture of cement, stone powder, and sand, with a volume ratio of 1:2:2. The cement strength is C20.

[0029] The flexible mold bag 5 is arranged at both ends of the high-risk area along the tunnel direction, located above the air duct cloth 4. The flexible mold bag 5 is filled with flexible mold bag filler to connect the surface of the flexible mold bag 5 with the top plate 102 of the high-risk area; two cuffs 5.1 are provided on the flexible mold bag 5, one cuff 5.1 is inserted into the air duct to blow air to inflate the flexible mold bag 5, and the other cuff 5.1 is inserted into the filling tube to inject the flexible mold bag filler.

[0030] Multiple groups of grouting pipes 6 pass through the spraying layer 1, the steel beam layer 2, the wooden board layer 3, and the air duct cloth 4 and are inserted into the space between the top plate 102 and the flexible mold bag 5 in the high-risk area; each group of grouting pipes 6 includes a main grouting pipe and a spare grouting pipe.

[0031] The high-risk area filler 7 is filled into the space enclosed by the air duct cloth 4, the high-risk area top plate 102 and the flexible mold bag 5 through the grouting pipe 6. The high-risk area filler 7 is an inorganic foaming material.

[0032] Example 2

[0033] This example uses the high-gas-burst area of Lane 53041 in a coal mine owned by the applicant as an example to illustrate the construction process of a roof-burst filling structure in a high-gas-burst area. The construction process primarily involves "sealing the bottom of an artificial false roof followed by filling the middle of the high-gas-burst area with pipes." The artificial false roof utilizes π-shaped beams, wooden boards, metal mesh, and air duct cloth, which are then gradually filled and sealed in sections. Filling the middle of the high-gas-burst area with pipes is then performed, and the filling material is poured and foamed to form the roof.

[0034] 1. Site Overview

[0035] The height of the high-risk area is measured every 3m (1 belt rack number) on site, and a schematic diagram is drawn as follows: Figure 3 The measurement parameters of each position are shown in Table 1.

[0036] Table 1: Plotting of measured data of high-risk areas in Lane 53041

[0037] serial number Location Width / m Total height of tunnel / m Falling height / m 1 100# belt rack 6.0 3.5 0 2 101# belt rack 6.0 5.3 1.5 3 102# belt rack 5.5 9.7 5.9 4 103# belt rack 6.3 10.4 6.6 5 104# belt rack 6.3 9.4 5.6 6 105# belt rack 6.9 8.4 4.6 7 106# belt rack 6.9 8.0 4.2 8 107# belt rack 7.3 8.4 4.6 9 108# belt rack 7.3 7.9 4.1 10 109# belt rack 6.6 7.7 3.9 11 110# belt rack 6.6 8.5 4.7 12 111# belt rack 6.4 7.2 3.4 13 112# belt rack 6.4 7.2 3.4 14 113# belt rack 6.3 3.7 0

[0038] The high-fall area is about 39m long and 6m wide, with a fall height ranging from 0 to 6.6m. The preliminary estimated space is 1000m 3 .

[0039] 2. The high-risk area is generally -12° downslope, with the top being the coal roof; an 800mm belt, 377# gas extraction pipeline and a wind duct are arranged on the east side of the tunnel, and wind and water pipelines and small lines are arranged on the west side. The pipelines are all below 4000mm in height, with a space of more than 1000mm on the non-pedestrian side, and no facilities on the pedestrian side.

[0040] 3. On-site technical conditions and equipment: QBY-40 pneumatic diaphragm pump and QB260 pneumatic mixing barrel are used for filling.

[0041] 2. Construction technical requirements:

[0042] 1) Artificial ceiling requirements and technical features

[0043] ① Due to the terrain, 4-inch steel pipes and large chains are first used as construction platforms from the inside to the outside in high-risk areas (two-layer platforms are set up in the super-high section) to meet the conditions for hanging π-shaped beams from the tunnel roof. 40T three-ring buckles and locks are used to hang wire ropes under the original support anchor cables, and matching rope clips, π-shaped beams, and wooden boards are used to build a false roof. At the same time, the height below the artificial false roof must be ensured to be no less than 4000-5500mm to meet the normal operation requirements in the tunnel. The height of the hanging steel beam should be flat (smooth) and stable according to the direction of the tunnel and the normal height of the tunnel. After a group of artificial false roofs are erected, the manual operation platform moves forward as the operation progresses.

[0044] The π-shaped beams are suspended vertically in the roadway (each row of suspension beams consists of two π-shaped steels, with both ends of the π-shaped steels close to the coal seam and fixed with 8# wire). The row spacing is 1000mm, and the π-shaped steel beams are suspended side by side (the π-shaped beams should be prepared in advance to the appropriate length according to the roadway width). Six suspension points are evenly arranged in each row of suspension beams (suspending points: a three-ring buckle / a lock / a steel wire rope of appropriate length / two rope clips at the end and end of the rope). When the on-site π-shaped steel beams need to be overlapped to meet the requirements of side-to-side suspension, the overlap length should be no less than 300mm (no less than two suspension points at the π-shaped steel overlap). At the same time, they should be firmly tied with wire or directly tied with steel wire ropes at the suspension points. To ensure the safety and reliability of the artificial false roof according to the actual situation at the work site, various parameters can be adjusted appropriately, and no cutting corners are allowed.

[0045] Note: When suspending the hanging beams with a row of six anchor cables at the top of the roadway, if some of the top anchor cables become stuck and cannot be lifted, the nearest anchor cable can be used to suspend them, ensuring that each row of hanging beams has six lifting points. To speed up the project, the first row of hanging beams during the shift can be suspended at three points to ensure balance and safety, while preparing for the next row. Before leaving the shift, ensure that all hanging beams suspended during the shift have six lifting points. Continue in this manner.

[0046] When loading materials on site, use safety ropes or hemp ropes to lift materials such as π-shaped steel after confirming safety. There is no need to set up a loading wood stack platform, and it is strictly prohibited to stand at the lifting site.

[0047] ② Laying wooden boards and air duct cloth

[0048] On top of the pre-constructed steel beam layer 2, lay wooden planks sequentially along the roadway. Ensure the planks are tightly stacked (and cut where necessary to ensure overlap) to ensure uniform force during filling. The planks and π-shaped steel are compacted and secured with rebar. Metal mesh can then be laid over the planks, tightly attached to the lower rebar with wire and tied together to prevent movement.

[0049] After the artificial ceiling is uniformly fabricated, two layers of wind tube cloth 4 are laid. As one of the main leak prevention measures, the wind tube cloth 4 must be laid tightly against the artificial ceiling, especially at the edges of high-risk areas. The height of the cloth must not be less than 0.5m. The wind tube cloth 4 is fixed to the coal seam with wire or other means. The overlap width of the wind tube cloth 4 is not less than 100mm.

[0050] ③Bottom spray sealing

[0051] Wooden boards and wind tube cloths cannot completely seal the top of the high-risk area. Once the filling in the high-risk area leaks, it is very difficult to deal with. Therefore, the bottom should be further sealed with spray grout. The thickness is recommended to be no less than 50mm. The thickness at the junction of the formwork and the lane wall is recommended to be thickened to 100mm.

[0052] Before spraying, a layer of mesh can be laid under the π-shaped beam to facilitate the adhesion of the sprayed layer 1. The sprayed material is a mixture of cement, stone powder, and yellow sand. The volume ratio of cement, stone powder, and yellow sand is 1:2:2, and the cement strength is C20.

[0053] In addition to ①②③, some anchor rods can also be arranged in the tunnels of the high-risk area, with a certain length exposed, as the skeleton of the high-risk area, which is more conducive to the stability of the filling material 7 in the high-risk area.

[0054] 2) Blocking requirements at both ends of high-risk areas

[0055] If you are worried about the difficulty of constructing the templates at both ends, you can adopt the hanging flexible mold bag filling method, which greatly reduces the template requirements.

[0056] Four flexible mold bags 5 are rectangular in shape, 5 meters long, 4 meters wide, and 3 meters high. Two are placed side by side, with the 5-meter-long bag running along the laneway's length and the 4-meter-wide bag running the width of the laneway. They are placed directly on the air duct cloth 4 without the need for hanging. Each flexible mold bag 5 has two cuffs 5.1 on the top, facing the open side. During use, one cuff 5.1 is inserted into the air duct to blow air, inflating the flexible mold bag 5. The other cuff is inserted into the filling tube to inject the flexible mold bag's filling material.

[0057] 3) Requirements for filling the central cannula in high-risk areas

[0058] After the two ends and the bottom are sealed, the middle can be filled. The cannula work can be pre-buried in advance when constructing the artificial false roof to ensure that the grouting pipe 6 is unobstructed. Pay attention to protecting the grouting port to prevent it from being blocked during spraying. At the same time, it can be used as an exhaust outlet for the enclosed space in the later stage.

[0059] Grouting pipe 6 uses a 6-point iron pipe. According to the slurry flow characteristics, a group of grouting pipes are inserted every 5m. The length of the grouting pipe should reach the top of the high-risk area. The insertion length of each group of pipes should be recorded. When filling in the future, fill from the lower part of the high-risk area first and then move to the higher part to prevent slurry from flowing.

[0060] Each set of grouting pipes uses two trips, with the same length and layout, one for backup and one for use. The backup grouting pipe also serves to vent and return grout to check whether the high-risk area is full.

[0061] High-risk area filling equipment and technology

[0062] 2.1 Filling system

[0063] The grouting system consists of two QB260 pneumatic mixing barrels and two slurry storage barrels (which can be made of iron barrels). The slurry stirred in the mixing barrels is placed in the slurry storage barrels. The two mixing barrels alternately prepare slurry to achieve continuous slurry supply. The grouting pumps used are two QBY-40 pneumatic diaphragm pumps, one for backup and one for use.

[0064] QBY-40 pneumatic diaphragm pump, maximum flow rate 8m 3 / h, maximum head 50m. QB260 pneumatic mixing drum, volume 260L.

[0065] 2.2 Filling process (grouting process): safety check → preparation → start grouting → pause grouting → end grouting → clean the pump and grouting pipeline.

[0066] 2.2.1 Preparation: Prepare filling materials, filling equipment, binding wires, etc. in advance. ① Transport the pump and accessories (including high-pressure hose for grouting, tools, grouting pipes, U-shaped clamps, connectors for connecting grouting pipes, etc.), filling materials, etc. to the construction site, and prepare a bucket of clean water (about 30L) for pre-construction testing and post-construction pump cleaning. ② Before connecting the pump to the air duct, open the air duct stop valve and blow away any residual water in the air duct. Then connect the suction pipe, grouting hose, pump, and pneumatic mixer. Connect the pump to the compressed air pipeline, check whether the amount of lubricating oil in the pump meets the requirements, and start the pump to check whether it can operate normally.

[0067] 2.2.2 Start grouting: If everything is in good condition, start mixing and filling. Work from the inside out, section by section. After connecting the grouting pipeline, open the output valve and pay attention to the grouting situation on site. Each group has two grouting pipes, one for grouting and the other as a spare grouting pipe, which also serves as an observation pipe. When liquid flows out of the other grouting pipe, the grouting effect is considered to be achieved (the filling liquid will solidify after 5 minutes), and the grouting is stopped. The next cycle is carried out until the grouting is completed. (After grouting, remember to turn off the diaphragm pump but not the stirring pump to prevent the liquid from solidifying).

[0068] The high-risk area filling material used this time is an EX-I inorganic foam material, which is non-corrosive, single-component, pure inorganic powder, completely flame retardant and antistatic. It is stirred with water during use, with a water-cement ratio of 2:1. It loses fluidity in about 6 minutes, solidifies in about 1 to 2 hours, expands by about 4 to 5 times, and has a filling density of 0.4g / cm 3 , the strength is about 1MPa, the reaction temperature does not exceed 40℃ (the on-site ventilation conditions are good, if the temperature at the operation site is higher than 34°, stop the operation immediately and take measures to strengthen ventilation), which meets all the requirements for high-risk area management.

[0069] The filling material in the high-risk area has the characteristics of foaming and expansion, which produces a certain extrusion force on the surrounding rock in the high-risk area. The surrounding rock in the high-risk area produces anti-fall friction on the filling body, which is more conducive to the stability of the filling body.

[0070] Use EX-I inorganic foam material for continuous filling. After the artificial false ceiling is erected, fill the high-risk area from the inside out and from bottom to top.

[0071] For simple high-risk area treatment, the filling material should be based on the main principles of light filling body, fast curing, high expansion multiple, small material consumption, and complete flame retardancy, so as to achieve the purpose of full filling and avoid gas accumulation.

[0072] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A roof-fall filling structure in a high-gas area of a coal mine, characterized in that: Including spraying layer, steel beam layer, wood board layer, air duct cloth, soft mold bag, grouting pipe and high-risk area filling; The steel beam layer is arranged below the high-risk area, and the height of the steel beam layer is the same as the normal height of the roadway. The steel beam layer includes multiple rows of hanging steel beams hung at equal intervals along the roadway direction, the length direction of the hanging steel beams is perpendicular to the roadway direction, and the two ends of the hanging steel beams are close to the coal seam; The wooden board layer includes multiple rows of wooden boards connected in sequence, and the wooden boards are fixedly laid on the hanging steel beams and are perpendicular to the hanging steel beams; The air duct cloth is fixedly laid on the wooden board layer, and the edge of the air duct cloth is fixedly connected to the coal seam; The shotcrete layer is arranged below the steel beam layer and the wood board layer, and the edge of the shotcrete layer is connected to the top plate of the normal area of the tunnel; The flexible mold bags are arranged at both ends of the high-risk area along the tunnel direction, above the wind tube cloth, and the flexible mold bags are filled with flexible mold bag fillings to connect the surface of the flexible mold bags with the top plate of the high-risk area; Multiple sets of grouting pipes pass through the spraying layer, steel beam layer, wooden board layer, and air duct cloth and are inserted into the space between the top plate and the flexible mold bag in the high-risk area; The high-risk area filler is filled into the space enclosed by the air duct cloth, the high-risk area top plate and the flexible mold bag through the grouting pipe.

2. The coal mine high gas area roof collapse filling structure according to claim 1, characterized in that: Each row of hanging steel beams includes two π-shaped steels with hanging points welded on them. The two ends of the π-shaped steels are fixed to the coal seam by iron wire.

3. The coal mine high gas area roof collapse filling structure according to claim 2, characterized in that: The wooden board and the π-shaped steel are compacted and tied together with steel bars, and a metal mesh is laid on top of the wooden board. The metal mesh is tightly attached to the steel bars and tied together with wire.

4. The coal mine high gas area roof collapse filling structure according to claim 1, characterized in that: The air duct cloth is fixedly connected to the coal seam by iron wire.

5. The coal mine high gas area roof collapse filling structure according to claim 1, characterized in that: The flexible mold bag is provided with two cuffs, which are respectively connected with the air duct and the filling tube.

6. The coal mine high gas area roof collapse filling structure according to claim 1, characterized in that: Each set of grouting pipes includes a main grouting pipe and a spare grouting pipe.

7. The coal mine high gas area roof collapse filling structure according to claim 2, characterized in that: A mesh is laid between the π-shaped steel and the shotcrete layer.

8. The coal mine high gas area roof collapse filling structure according to claim 7, characterized in that: The material of the shotcrete layer is a mixture of cement, stone powder and yellow sand. The volume ratio of cement, stone powder and yellow sand is 1:2:2, and the cement strength is C20.

9. The coal mine high gas area roof collapse filling structure according to claim 1, characterized in that: The filling material in the high-risk area is inorganic foam material.

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