A filling bag, a simultaneous mining and filling diaphragm wall and a construction method

Abstract

This invention provides a filling bag, comprising a first isolation section and a second isolation section connected adjacent to each other. A first grouting space and a second grouting space are respectively provided within the first isolation section and are interconnected. The rock strata of the overlying rock in the stope are defined as m, and n layers deform synchronously from bottom to top, where n ≤ m, and the elastic modulus of each rock stratum is E. i Thickness h i The volume force is r i Where q1 is the self-weight load directly bearing the entire rock strata; I i Let be the moment of inertia of the i-th rock layer; B is the cross-sectional width of the beam, i.e., the width of the filling bag, which can be regarded as the width of the filling bag; E i Let h be the elastic modulus of the i-th rock layer. i Let be the thickness of the i-th rock layer.

Description

Technical Field

[0001] This invention belongs to the field of mine backfilling, specifically relating to a backfilling bag, a backfilling isolation wall that is filled during mining, and a construction method thereof. Background Technology

[0002] The intensive mining of metallic and non-metallic minerals and coal resources has led to the emergence of large-scale goaf areas, resulting in problems such as surface subsidence, aquifer damage, soil erosion, waste rock dumping, gas disasters, and large-scale roof collapses and hurricane-induced damage, thus causing regional ecological disorder. To address these ecological problems arising from mining, mine backfilling technology has emerged. With increasing mining intensity and the need for resource recovery, backfilling technology has rapidly advanced. Currently, backfilling technologies include solid backfilling, (ultra) high-water backfilling, and paste backfilling. (Ultra) high-water and paste backfilling technologies are increasingly favored in mining operations due to their high strength and stability.

[0003] However, in high-water and paste-filled mining, due to the longer setting time, lower initial bleeding, and poorer strength of the slurry compared to solid filling, it is necessary to construct isolation walls to separate the goaf from the mining area and prevent slurry from flowing into the mining area. Therefore, isolation walls play a crucial role in backfilling mining. Currently, the main construction forms of isolation walls include brick structures, wooden structures, concrete structures, and steel structures. Among them, brick and wooden structures are usually used for small-section roadways, while concrete and steel structures can be applied to the construction of retaining walls for large-section roadways.

[0004] Existing infill retaining walls have the following disadvantages:

[0005] On the one hand, the filling slurry has a slow bleeding rate and a long setting time, and the filling slurry remains in a liquid state in the goaf for a long time. Therefore, during the filling process, it is necessary to construct an isolation wall to prevent the slurry from spreading and overflowing. Usually, the filling hydraulic support is used to isolate the filling slurry, which takes up a long production time of the hydraulic support and results in low overall production capacity of the mining area.

[0006] Secondly, if the goaf cannot be filled in time during the mining process, it will cause the roof of the goaf to collapse, the roadway to be damaged, the aquifer to be destroyed, gas to emerge and explode, etc., which will bring major safety hazards to underground mining production. Therefore, hydraulic supports are needed.

[0007] Thirdly, the existing bag-filled retaining wall technology is complex due to the large number of retaining walls, their dispersed locations, and the high strength requirements of the retaining walls. It requires a lot of manpower and material resources, and the filling efficiency is not high. Summary of the Invention

[0008] In view of the shortcomings of the existing technology, the purpose of this invention is to provide a filling bag, a filling isolation wall that is filled as it is mined, and a construction method thereof, thereby solving the problems existing in the prior art.

[0009] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0010] A filling bag includes a first isolation section and a second isolation section connected adjacent to each other, wherein a first grouting space and a second grouting space are respectively provided in the first isolation section and the second isolation section, and the first grouting space and the second grouting space are connected.

[0011] Let the overlying rock strata in the mining area be m, and let n layers deform synchronously from bottom to top, where n ≤ m, and let the elastic modulus of each rock stratum be E. i Thickness h i The volume force is r i ;

[0012]

[0013]

[0014]

[0015]

[0016] Where q1 is the self-weight load directly bearing all the rock strata; I i Let be the moment of inertia of the i-th rock layer; B is the cross-sectional width of the beam, i.e., the width of the filling bag, which can be regarded as the width of the filling bag; E i Let h be the elastic modulus of the i-th rock layer. i Let r be the thickness of the i-th rock layer. i Let be the volumetric force of the i-th rock layer, where i = 1, 2, 3, ..., m; R represents the strength of the infill material with width B and height h; where q1 is equal to R, R c denoted as uniaxial compressive strength of the rock strata, i.e., the compressive strength of the retaining wall material; F is the pressure exerted on the filling bag; b is the width of the mining area; h is the height of the mining area; and θ is the angle between the two sides of the filling bag embedded in the goaf.

[0017] Preferably, the first isolation wall includes a first plate (101) and a second plate (102) arranged opposite to each other to form a first grouting space. Air outlets (3) are respectively provided on the side of the first plate (101) and the second plate (102) away from the second isolation wall. Injection holes (2) are provided on the first plate (101) or the second plate (102). The side of the first plate (101) and the second plate (102) away from the second isolation wall is connected by a first connector.

[0018] The second isolation wall includes a third plate (103), a fourth plate (104) and a fifth plate (105). One end of the third plate (103) and the fourth plate (104) are respectively located at both ends of the fifth plate (105) and connected to it, and the other end is respectively connected to the first plate (101) and the second plate (102). The third plate (103), the fourth plate (104) and the fifth plate (105) enclose a second grouting space.

[0019] Preferably, the first plate (101) and the second plate (102) are respectively provided with fixing holes (4) on the side away from the second isolation wall, and the two ends of the first connector are respectively provided in the corresponding fixing holes (4). The first connector is a steel wire rope, iron wire or bandage.

[0020] Preferably, the included angle between the third plate, the fourth plate and the fifth plate is 30° to 60°.

[0021] A filling isolation wall that is filled as it is extracted includes multiple filling bags (1) as described above, and each filling bag (1) is arranged adjacent to each other along its length and connected by a second connector (5).

[0022] Preferably, the second connector (5) is a high-strength adhesive cloth, which includes a first adhesive part and a second adhesive part. The first adhesive part is disposed on the first plate or the second plate of two adjacent filling bags, and the second adhesive part is bonded to the first adhesive part.

[0023] A method for constructing a filling isolation wall during mining, wherein the method uses the filling bag (1) or the filling isolation wall during mining as described above.

[0024] Preferably, the method includes:

[0025] Step 1: In the mining area, the number of overlying rock layers is m, and the elastic modulus of each layer is E. i Thickness h i The volume force is r i Moment of inertia I of the rock strata i Formula 1 is used to determine the self-weight load of all rock strata on the direct roof of the coal seam as q1. When the self-weight load is equal to the strength R of the filling body, Formula 2 is used to determine the width B of the filling bag. Formula 3 is then used to determine the pressure on the filling bag. During the selection of the filling bag, the corresponding filling bag material is determined by comparing it with the pressure borne by the materials used in different filling bags. According to the width of the goaf in the mine, the filling bag of the corresponding size is selected. The filling bags are placed adjacent to each other in a direction perpendicular to the working face to form an isolation wall. Behind the hydraulic support, the filling bag 1 is suspended on the anchor bolt or anchor cable of the roadway roof by passing through the fixing hole 4 with steel wire rope, iron wire or bandage. High-strength adhesive cloth 5 is pasted on each filling bag.

[0026] Step 2: Use the surface slurry preparation system to transport the slurry to the well. Inject (ultra) high water or paste slurry into the injection hole 2 of the first filling bag 1 through the underground slurry delivery pipeline. Fill the lower part first and then fill the upper part.

[0027] Step 3: Use FLAC finite difference software to numerically simulate the roof failure law of the coal mining face, thereby determining the filling step distance. Repeat steps 1 and 2 within a certain filling step distance, and inject slurry into each filling bag in sequence.

[0028] Step 4: After the filling isolation wall has solidified, use a small drilling rig to drill observation holes at different heights on the isolation wall. The diameter of the observation holes is about 10mm. The height of the slurry level is determined through the observation holes. When the slurry level exceeds the observation hole, use cement columns of the same size to block the observation hole in sequence. After the isolation wall has solidified, the hydraulic support can be removed. The direct top plate between the filling bag isolation walls collapses, and the pre-cut casing of horizontal well 8 is exposed, providing a conveying channel for slurry filling. Use the top plate horizontal well 8 to convey slurry and fill the space between the filling bag isolation walls.

[0029] Step 5: Advance along the direction of coal face 7, such as... Figure 3 and 4 Repeat steps one through four within the goaf area to complete the filling of the goaf.

[0030] 9. The method for constructing an isolation wall by filling as described in claim 8, characterized in that, in step two, during the filling process, in order to ensure the formation and uniform top connection of the filling body, every 200-300mm of filling, the filling bag 1 is checked for sagging or tilting. At the same time, during the filling process, the air in the filling bag is discharged outside the bag through the air outlet 3. After the filling is completed, the injection hole 2 is tied tightly with a rope to prevent the slurry from overflowing.

[0031] Compared with the prior art, the present invention has the following technical effects:

[0032] (I) During mining operations, an isolation wall is constructed behind the hydraulic supports. Firstly, the isolation wall supports the roof of the roadway, preventing roof collapse and potential safety hazards. Secondly, the construction of the isolation wall prevents the diffusion and leakage of slurry during filling. Thirdly, the use of filling bags to construct the isolation wall greatly improves construction efficiency. During construction, filling bags are fixed sequentially along the width of the working face, and filling can begin immediately without the need for other support devices, simplifying the construction process. Fourthly, the slurry inside the filling bags is directly injected through the underground pipeline system to form the retaining wall, facilitating the release of the hydraulic supports and thus improving mining efficiency. Fifthly, the bottom-large, top-small structure of the filling bags contributes to the self-supporting stability of the retaining wall, eliminating the need for other support devices and enhancing its anti-overturning performance, meeting the filling needs of large-scale, high-intensity mining areas. Sixthly, the filling bags can be designed in different sizes to meet the needs of different coal mining faces.

[0033] (II) This invention uses formulas 1-4 to quantitatively determine the final setting strength of the slurry, the width of the filling bag, and the pressure that the filling bag bears during the filling process, based on the different mining needs of different filling areas and different slurry properties. This provides a quantitative calculation method for the selection of filling bag materials, thereby laying a certain foundation for the accurate selection of filling bags for different working conditions. At the same time, the formation of the retaining wall helps to release the hydraulic support for mining, thereby greatly improving the efficiency of mining. Attached Figure Description

[0034] Figure 1 This is an overall schematic diagram of the filling bag of the present invention;

[0035] Figure 2 This is an overall schematic diagram of the filling bag of the present invention;

[0036] Figure 3 This is a perspective view of the isolation wall structure of the present invention;

[0037] Figure 4 This is a top view of the filling operation;

[0038] Figure 5 This is a cross-sectional view of the filling operation.

[0039] The meanings of the labels in the diagram are as follows:

[0040] 1. Filling bag, 2. Injection hole, 3. Vent hole, 4. Fixing element, 5. High-strength adhesive, 6. Filling body, 7. Coal seam, 8. Horizontal well, 1-1. First plate, 1-2. Second plate, 1-3. Third plate, 1-4. Fourth plate, 1-5. Fifth plate, 101-First plate, 102-Second plate, 103-Third plate, 104-Fourth plate, 105-Fifth plate.

[0041] The specific content of the present invention will be further explained in detail below with reference to the embodiments. Detailed Implementation

[0042] The following are specific embodiments of the present invention. It should be noted that the present invention is not limited to the following specific embodiments. All equivalent modifications made based on the technical solutions of this application fall within the protection scope of the present invention.

[0043] Example 1:

[0044] A type of filling bag, such as Figure 1-2 As shown, the overburden rock strata in the mining area are defined as m, and the elastic modulus of each stratum is E. i Thickness h i The volume force is r i Calculate the width B of the filling bag and the pressure F exerted on the filling bag using the following formulas:

[0045]

[0046]

[0047]

[0048]

[0049] Where q1 is the self-weight load directly bearing the entire rock strata; I i Let be the moment of inertia of the i-th rock layer; B is the cross-sectional width of the beam, i.e., the width of the filling bag, which can be regarded as the width of the filling bag; E i Let h be the elastic modulus of the i-th rock layer. i Let r be the thickness of the i-th rock layer. i Let be the volumetric force of the i-th rock layer, where i = 1, 2, 3, ..., m; R represents the strength of the infill material with width B and height h; where q1 is equal to R, R c denoted as uniaxial compressive strength of the rock strata, i.e., the compressive strength of the retaining wall material; F is the pressure exerted on the filling bag; b is the width of the mining area; h is the height of the mining area; and θ is the angle between the two sides of the filling bag embedded in the goaf.

[0050] When the strength R of the filling material c When the self-weight load q1 of all rock strata is equal, under certain working conditions, the final setting strength of the slurry, the width of the filling bag, and the pressure on the filling bag during the filling process can be determined according to formulas 1, 2, 3 and 4, thus providing a basis for the selection of filling bag materials.

[0051] This filling bag, based on the different filling area requirements and slurry properties, uses formulas 1-4 to quantitatively determine the final setting strength of the slurry, the width of the filling bag, and the pressure the filling bag bears during filling. This provides a quantitative calculation method for the selection of filling bag materials, thus laying a foundation for the accurate selection of filling bags for different working conditions. At the same time, the formation of the retaining wall helps to release the hydraulic support for mining, thereby greatly improving the efficiency of mining.

[0052] Example 2:

[0053] like Figure 1 and Figure 2 As shown, this embodiment of the invention provides a filling bag, a filling isolation wall that is filled during mining, and a construction method. The filling bag includes a filling bag 1, an injection hole 2, an air outlet 3, a fixing hole 4, and a high-strength adhesive cloth 5 for sealing between the bags. The filling bag 1 has a shape that is wider at the bottom than at the top, which is beneficial to the stability of the isolation wall. Simultaneously, the filling bag has a certain degree of water permeability, which helps the slurry to seep water, thereby accelerating the solidification of the slurry. The injection hole 2 provides a filling channel for the slurry, and the size of the injection hole is matched according to the size of the filling pipe. The air outlet 3 is used to expel air from inside the filling bag 1 during the slurry filling process. Multiple fixing holes 4 are distributed on the upper part of the filling bag 1. The filling bag 1 is fixed to the anchor bolts or anchor cables on the roadway roof by passing high-strength bandages, wires, or steel cables through the fixing holes 4, thus opening the filling bag 1. The high-strength adhesive cloth 5 is used to seal the gaps between the filling bags 1.

[0054] In this embodiment, the included angle between the third plate, the fourth plate and the fifth plate is 45°, which ensures that the second isolation section has stronger stability under test.

[0055] Example 3:

[0056] This invention also provides a method for constructing and filling a mining-as-you-go isolation wall, comprising the following steps:

[0057] Taking a coal seam in the Northwest region with high-intensity mining as an example, the coal seam is buried at a depth of 300-500m, with a thickness of about 3m, a working face width of about 200-300m, and a working face length of 2000-3000m. It contains 13 rock strata from the top of the coal seam to the surface. The roof failure law of the coal mining face was numerically simulated using FLAC finite difference software, and the filling step distance was determined to be about 5m.

[0058] Step 1: As Figure 3 and Figure 4As shown, based on the width of the goaf in the mine, a 6m wide filling bag 1 is selected and arranged in sequence perpendicular to the direction of the working face. Behind the hydraulic support, the filling bag 1 is suspended from the anchor bolt or anchor cable on the roof of the roadway by passing through the fixing hole 4 with a steel wire rope, iron wire or bandage. High-strength adhesive cloth 5 is pasted between the bags to prevent the grout from running out and leaking during the filling process between the isolation walls later.

[0059] Step 2: Use the surface slurry preparation system to transport the slurry to the well. Inject (ultra) high water or paste slurry into the injection hole 2 of the first filling bag 1 through the underground slurry delivery pipeline. Fill the lower part first and then the upper part. During the filling process, in order to ensure the formation and uniform connection of the filling body, check whether the filling bag 1 has sagged or tilted every 200-300mm of filling. At the same time, during the filling process, the air in the filling bag is discharged from the bag through the air outlet 3. After filling is completed, tie the injection hole 2 tightly with a rope to prevent the slurry from overflowing.

[0060] Step 3: Repeat steps 1 and 2 within a certain filling interval, and inject slurry into each filling bag in sequence;

[0061] Step 4: After the filling isolation wall has solidified, use a small drilling rig to drill observation holes at different heights on the isolation wall. The diameter of the observation holes is about 10mm. The height of the slurry level is determined through the observation holes. When the slurry level exceeds the observation hole, use cement columns of the same size to block the observation holes one by one. After the isolation wall has solidified, the hydraulic support can be removed, and the direct top plate between the filling bag isolation walls collapses. The pre-cut casing of horizontal well 8 is exposed, providing a conveying channel for slurry filling. The slurry is conveyed through horizontal well 8 on the top plate to fill the space between the filling bag isolation walls.

[0062] Step 5: Advance along the direction of the coal mining face 7, such as... Figure 3 and 4 Repeat steps 1 to 4 within the goaf to complete the filling of the goaf.

Claims

1. A filling bag, characterized in that, It includes a first isolation section and a second isolation section that are adjacent to each other. A first grouting space and a second grouting space are respectively set in the first isolation section and the second isolation section. The first grouting space and the second grouting space are connected. Let the overlying rock strata in the mining area be m, and let n layers deform synchronously from bottom to top, where n ≤ m, and the elastic modulus of each rock layer be... Thickness is The volume force is Calculate the width of the filling bag using the following formula. B The pressure on the filling bag F : (Equation 1) (Equation 2) (Equation 3) (Equation 4) in, To directly bear the self-weight load of the entire rock strata; Let be the moment of inertia of the i-th rock layer; The width of the beam's cross-section can be considered as the width of the filling bag; Let be the elastic modulus of the i-th rock layer. Let be the thickness of the i-th rock layer. Let be the volume force of the i-th rock layer, where i = 1, 2, 3, ..., m; Indicates width is Height is The strength of the filling material; among which, and equal, This refers to the uniaxial compressive strength of the rock strata, which is also the compressive strength of the retaining wall material. The pressure exerted on the filling bag, The width of the mining area, The height of the mining area, The filling bag is embedded at the included angle between the two sides of the goaf; The first isolation section includes a first plate (101) and a second plate (102) arranged opposite to each other to form a first grouting space. Air outlets (3) are respectively provided on the side of the first plate (101) and the second plate (102) away from the second isolation section. Injection holes (2) are provided on the first plate (101) or the second plate (102). The side of the first plate (101) and the second plate (102) away from the second isolation section is connected by a first connector. The second isolation section includes a third plate (103), a fourth plate (104) and a fifth plate (105). One end of the third plate (103) and the fourth plate (104) are respectively located at both ends of the fifth plate (105) and connected to it, and the other end is respectively connected to the first plate (101) and the second plate (102). The third plate (103), the fourth plate (104) and the fifth plate (105) enclose and form a second grouting space.

2. The filling bag as described in claim 1, characterized in that, The first plate (101) and the second plate (102) are respectively provided with fixing holes (4) on the side away from the second isolation section. The two ends of the first connector are respectively provided in the corresponding fixing holes (4). The first connector is a steel wire rope, iron wire or bandage.

3. The filling bag as described in claim 1, characterized in that, The included angle between the third, fourth and fifth plates is 30° to 60°.

4. A filling isolation wall that is filled as needed, comprising a plurality of filling bags (1) as described in claim 1 or 2, wherein each filling bag (1) is arranged adjacent to each other along its length and connected by a second connector (5).

5. The infill isolation wall as described in claim 4, characterized in that, The second connector (5) is a high-strength adhesive cloth, which includes a first adhesive part and a second adhesive part. The first adhesive part is disposed on the first plate or the second plate of two adjacent filling bags, and the second adhesive part is bonded to the first adhesive part.

6. A method for constructing a mining-and-filling isolation wall, characterized in that, The method uses the filling bag (1) as described in claim 2 or the filling isolation wall as described in claim 5.

7. The method for constructing a mining-and-filling isolation wall as described in claim 6, characterized in that, The method includes: Step 1: In the mining area, the number of overlying rock layers is m, and the elastic modulus of each layer is... Thickness is The volume force is Moment of inertia of rock strata Therefore, Formula 1 is used to determine the total self-weight load of all rock strata on the immediate roof of the coal seam. When the self-weight load and the strength of the filling material When they are equal, use Formula 2 to determine the width of the filling bag. Then, the pressure on the filling bag is determined by formula 3. During the selection of the filling bag, the corresponding filling bag material is determined by comparing it with the pressure borne by the materials used in different filling bags. According to the width of the goaf in the mine, the filling bag of the corresponding size is selected. The filling bags are placed adjacent to each other in the direction perpendicular to the working face to form an isolation wall. The filling bag 1 is suspended on the anchor rod or anchor cable of the roadway roof by passing through the fixing hole (4) with steel wire rope, iron wire or bandage behind the hydraulic support. High-strength adhesive cloth is pasted on each filling bag (5). Step 2: Use the ground slurry preparation system to transport it to the well. Inject high water material, ultra-high water material or paste slurry into the injection hole (2) of the first filling bag (1) through the underground slurry delivery pipeline. Fill the lower part first and then fill the upper part. Step 3: Use FLAC finite difference software to numerically simulate the roof failure law of the coal mining face, thereby determining the filling step distance. Repeat steps 1 and 2 within a certain filling step distance, and inject slurry into each filling bag in sequence. Step 4: After the filling isolation wall has solidified, use a small drilling machine to drill observation holes at different heights on the isolation wall. The diameter of the observation holes is about 10mm. The height of the slurry level is determined through the observation holes. When the slurry level exceeds the observation hole, use cement columns of the same size to block the observation holes in sequence. After the isolation wall has solidified, the hydraulic support can be removed. The direct top plate between the filling bag isolation walls collapses, and the pre-cut casing of the horizontal well (8) is exposed, providing a conveying channel for slurry filling. The slurry is conveyed through the top plate horizontal well (8) to fill the space between the filling bag isolation walls. Step 5: Along the direction of the advance of the coal mining face (7), repeat steps 1 to 4 in the goaf area to complete the filling of the goaf area.

8. The method for constructing a mining-and-filling isolation wall as described in claim 7, characterized in that, In step two, during the filling process, in order to ensure the formation and uniform top of the filling body, check whether the filling bag (1) has fallen or tilted every 200~300mm of filling. At the same time, during the filling process, the air in the filling bag is discharged out of the bag through the air outlet (3). After the filling is completed, the injection hole (2) is tied tightly with a rope to prevent the slurry from overflowing.

Images