Coal mine underground reservoir and its construction method

Abstract

The present application provides a coal mine underground water reservoir and its construction method, which relates to the field of coal mine technology. The coal mine underground water reservoir includes: a reservoir dam body, which is located on the periphery of the goaf after coal seam mining, and the reservoir dam body includes a coal pillar dam body formed around the goaf; a roof, which is located above the goaf; a bottom plate, which is located below the goaf, and the reservoir dam body, the roof, and the bottom plate together form a water storage area; a structure, which is arranged in the water storage area, and the structure includes a dam foundation, a dam body, and anchor rods, the bottom of the dam foundation is connected to the bottom plate, the dam body is arranged at the top of the dam foundation, and the anchor rods are passed through the dam foundation to connect the bottom plate and the dam body; wherein the dam body is a pyramid structure, the bottom surface of the pyramid structure is connected to the dam foundation, and the apex of the pyramid structure faces the roof. Therefore, the dam body of the pyramid structure can slow down the impact of the roof overburden collapse on the water, slow down the shearing effect of water on the coal pillar dam body, and is conducive to improving the stability and reliability of the coal pillar dam body.

Description

Technical Field

[0001] The present application relates to the field of coal mine technology, and in particular to a coal mine underground water reservoir and a construction method thereof. Background Art

[0002] The energy "Golden Triangle" region (Shanxi, Shaanxi, Inner Mongolia, Ningxia, and Gansu) is my country's primary coal production area. However, located in an arid and semi-arid climate zone, water shortages have long been a problem. Therefore, underground coal mine reservoirs are often used to address water supply issues in water-scarce mining areas. Underground coal mine reservoirs utilize the interstices between collapsed rock masses within coal mine goafs to store mine water. Using underground coal mine goafs as storage, purification, and recycling space effectively protects and utilizes mine water resources, promotes ecological restoration and green mining, and meets my country's requirements for green mining and sustainable development. However, the coal pillar dams surrounding the goafs, in addition to being subject to in-situ rock stress, may also be subject to shear impact loads from groundwater caused by roof rock collapse above the water storage area, posing a significant threat to the stability of the coal pillar dams. Summary of the Invention

[0003] The Summary of the Invention introduces a series of simplified concepts that will be further described in the Detailed Description of the Invention. This section of the invention is not intended to limit the key features and essential features of the claimed technical solution, nor is it intended to determine the scope of protection of the claimed technical solution.

[0004] An embodiment of the first aspect of the present application provides an underground water reservoir in a coal mine, comprising: a reservoir dam body, located on the periphery of the goaf after coal seam mining, the reservoir dam body including a coal pillar dam body formed around the goaf; a roof, located above the goaf; a bottom plate, located below the goaf, the reservoir dam body, the roof and the bottom plate together forming a water storage area; a structure, arranged in the water storage area, the structure including a dam foundation, a dam body and anchor rods, the bottom of the dam foundation is connected to the bottom plate, the dam body is arranged at the top of the dam foundation, and the anchor rods are passed through the dam foundation to connect the bottom plate and the dam body; wherein the dam body is a pyramidal structure, the bottom surface of the pyramidal structure is connected to the dam foundation, and the apex of the pyramidal structure faces the roof.

[0005] Exemplarily, the dam foundation includes an outer shell and a non-Newtonian fluid filling material filled in the outer shell, the outer shell and the dam body are cast with concrete, and / or the number of the anchor rod is at least one.

[0006] Exemplarily, the non-Newtonian fluid filling material includes a shear-thickening non-Newtonian fluid; and / or, the outer shell is a rectangular box structure, and the dam body is a regular quadrangular pyramid structure.

[0007] For example, a plurality of structures are arranged in rows in the goaf, and two adjacent rows of structures are arranged in a staggered manner.

[0008] For example, the distance between two adjacent structures in the same row is 13m to 17m; the distance between two adjacent rows of structures is 18m to 22m; the structures in the same row are spaced apart horizontally, and multiple rows of structures are spaced apart vertically, and the longitudinal direction is parallel to the advancing direction of the working face of coal seam mining.

[0009] Exemplarily, the top of the dam body is higher than the liquid level of the water storage area, and the height difference between the top of the dam body and the liquid level of the water storage area is greater than or equal to 0.2 m.

[0010] Exemplarily, the coal mine underground water reservoir also includes: a liquid conveying device, which is connected to the water storage area and is used to extract or recharge the liquid in the water storage area; and / or the reservoir dam body also includes an artificial dam body connected to the coal pillar dam body, and at least part of the artificial dam body is located on the side of the reservoir dam body adjacent to the working face.

[0011] Exemplarily, the coal mine underground water reservoir also includes multiple stress detection devices and sandbags. The multiple stress detection devices are arranged at intervals on the coal pillar dam. The stress detection devices are used to detect the stress of the coal pillar dam at relative positions. The sandbags are arranged in the protection area of the coal pillar dam. The protection area includes the area of the coal pillar dam corresponding to the stress detection device with abnormal detection value.

[0012] An embodiment of the second aspect of the present application provides a construction method for a coal mine underground water reservoir, which is used to construct a coal mine underground water reservoir of any of the aforementioned embodiments. The construction method of the coal mine underground water reservoir includes: performing pretreatment operations on the goaf formed after coal seam mining; performing structure construction, wherein the steps of performing structure construction include: constructing the outer shell of the dam foundation in the goaf after the pretreatment operation, passing the first end of the anchor rod through the outer shell and fixing it to the bottom plate below the goaf, pouring non-Newtonian fluid filling material into the outer shell, constructing the dam body, and fixing the second end of the anchor rod, the dam body is a pyramid structure, the bottom surface of the pyramid structure is connected to the dam foundation, and the apex of the pyramid structure faces the roof above the goaf; performing sandbag protection operations, wherein the steps of performing sandbag protection operations include: arranging stress detection devices at different positions of the coal pillar dam body, and arranging sandbags in the area of the coal pillar dam body corresponding to the stress detection device with abnormal detection value.

[0013] Exemplarily, the construction method of an underground water reservoir in a coal mine also includes: constructing an artificial dam body, at least part of which is located on the side of the reservoir dam body adjacent to the working face, and is configured to connect two adjacent goafs; wherein, before the step of constructing the artificial dam body, it also includes: using a liquid conveying device to extract the liquid in the goaf where the liquid is stored; and / or performing pretreatment operations on the goaf formed after coal seam mining, performing structure construction, and performing sandbag protection operations.

[0014] Illustratively, the step of performing pre-processing operations on the goaf formed after coal seam mining includes: cleaning the coal gangue in the goaf at a preset distance from the coal pillar dam, where the preset distance is 80m to 120m.

[0015] The coal mine underground water reservoir and its construction method provided in the embodiment of the present application include a reservoir dam body, a roof, a bottom plate and a structure. The structure is arranged in the water storage area. The bottom of the dam foundation of the structure is connected to the bottom plate, the dam body is arranged at the top of the dam foundation, the anchor rods are passed through the dam foundation, and the two ends of the anchor rods are respectively fixed to the bottom plate and the dam body. By setting the dam body as a pyramid structure, the bottom surface of the pyramid structure is connected to the dam foundation, the apex of the pyramid structure faces the roof, and an inclined side surface is connected between the apex and the bottom surface of the dam body. In this way, when the rock of the roof (such as overburden) collapses, the top of the dam body can support the collapsed roof, and the inclined side surfaces between the top and the bottom surface of the dam body can support the collapsed roof, so that the shear force can be distributed more evenly on the bottom surface, thereby reducing the phenomenon of local stress concentration. The inclined side surfaces provide good support and stability, further enhancing the shear resistance of the structure, thereby slowing down the impact of the collapse of the overburden on the water, slowing down the shear effect of water on the coal pillar dam body, and helping to improve the reliability of the coal pillar dam body.

[0016] Furthermore, the dam body of the structure is a regular tetrahedron structure, and the tip of the regular tetrahedron structure has a supporting effect on the collapsed roof. The shear-thickening non-Newtonian fluid filled in the inner cavity of the dam foundation of the structure can further buffer the vertical impact caused by the collapse of the roof. The staggered arrangement of several structures can achieve the purpose of gradually reducing the shear impact of groundwater. The above structure and structure arrangement method can effectively reduce the shear impact load of groundwater on the coal pillar dam body caused by the collapse of the roof above the water storage area. In addition, the present application sets a stress detection device at the coal pillar dam body to monitor the stress concentration area of the coal pillar dam body, and then reinforces the stress concentration area with sandbags. The above method can effectively improve the stability of the coal pillar dam body of the coal mine underground water reservoir.

[0017] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are specifically listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Various other advantages and benefits will become apparent to those skilled in the art upon reading the detailed description of the preferred embodiment below. The accompanying drawings are for illustration purposes only and are not to be considered as limiting the present invention. The same reference numerals are used throughout the accompanying drawings to denote the same components.

[0019] Figure 1 One of the structural schematic diagrams of a coal mine underground water reservoir in the related art is shown;

[0020] Figure 2 One of the schematic block diagrams showing a partial structure of a coal mine underground water reservoir provided by an embodiment of the present application;

[0021] Figure 3 One of the structural schematic diagrams of the structure provided in the embodiment of the present application is shown;

[0022] Figure 4 A second schematic diagram showing a partial structure of a coal mine underground water reservoir provided in an embodiment of the present application;

[0023] Figure 5 One of the flow charts of the construction method of the coal mine underground water reservoir provided in the embodiment of the present application is shown.

[0024] in, Figure 1 The corresponding relationship between the reference numerals and component names is as follows:

[0025] 100' coal mine underground water reservoir, 111' coal pillar dam, 1111' first coal pillar dam, 1112' second coal pillar dam, 112' artificial dam, 120' roof, 140' water storage area, 160' gangue.

[0026] in, Figures 2 to 4 The corresponding relationship between the reference numerals and component names is as follows:

[0027] 100 coal mine underground water reservoir, 101 goaf, 110 reservoir dam body, 111 coal pillar dam body, 1111 first coal pillar dam body, 1112 second coal pillar dam body, 112 artificial dam body, 113 strike protection coal pillar, 120 roof, 130 structure, 131 dam foundation, 1311 outer shell, 1312 non-Newtonian fluid filling material, 1313 side wall, 1314 bottom wall, 1315 top wall, 132 dam body, 1321 bottom surface, 1322 apex, 133 anchor rod, 140 water storage area, 150 bottom plate. DETAILED DESCRIPTION

[0028] In order to more clearly understand the above-mentioned objects, features and advantages of the present invention, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that the embodiments of the present invention and the features therein can be combined with each other without conflict.

[0029] In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein. Therefore, the scope of protection of the present invention is not limited to the specific embodiments disclosed below.

[0030] like Figure 1 As shown, a related art coal mine underground water reservoir 100' includes a coal pillar dam 111' and an artificial dam 112' surrounding the goaf after coal seam mining. Gangue 160' is located within the goaf, and water is stored in the gaps within the gangue 160'. When using coal mine underground water reservoir 100' for water storage, a sudden collapse of the overburden of the roof 120' above the water storage area 140' could create a dynamic impact on the water. This transfer of water would exert horizontal shear forces on coal pillar dam 111', seriously compromising its stability.

[0031] For this reason, Figure 2 and Figure 3 As shown, the embodiment of the first aspect of the present application provides a coal mine underground water reservoir 100, comprising: a reservoir dam body 110, located on the periphery of a goaf 101 after coal seam mining, the reservoir dam body 110 including a coal pillar dam body 111 formed around the goaf 101; a top plate 120, located above the goaf 101; a bottom plate 150, located below the goaf 101, the reservoir dam body 110, the top plate 120, and the bottom plate 150 together form a water storage area 140; a structure 130, arranged in the water storage area 140, The structure 130 includes a dam foundation 131, a dam body 132 and an anchor rod 133. The bottom of the dam foundation 131 is connected to the bottom plate 150, and the dam body 132 is arranged on the top of the dam foundation 131. The first end of the anchor rod 133 is passed through the inside of the dam foundation 131 and connected to the dam foundation 131 and the bottom plate 150. The second end of the anchor rod 133 is passed through the dam foundation 131 and connected to the dam body 132. The dam body 132 is a pyramid structure, the bottom surface 1321 of the pyramid structure is connected to the dam foundation 131, and the vertex 1322 of the pyramid structure faces the top plate 120.

[0032] The coal mine underground water reservoir 100 provided in the embodiment of the present application includes a reservoir dam body 110, a roof 120, a bottom plate 150 and a structure 130, wherein the roof 120 is located above the goaf 101 and may be a coal seam roof 120, and the bottom plate 150 is located below the goaf 101 and may be a coal seam bottom 150, and the reservoir dam body 110, the roof 120 and the bottom plate 150 together form a water storage area 140 for storing groundwater. Structure 130 is located within water storage area 140. The bottom of the dam foundation 131 of structure 130 is connected to the bottom plate 150, and the dam body 132 is located on the top of the dam foundation 131. Anchor rods 133 are inserted through the dam foundation 131, and the ends of the anchor rods 133 are fixed to the bottom plate 150 and the dam body 132, respectively. Dam body 132 is configured as a pyramidal structure, with the bottom surface 1321 of the pyramidal structure connected to the dam foundation 131 and the apex 1322 of the pyramidal structure facing the top plate 120. It can be understood that an inclined side surface connects the apex 1322 and bottom surface 1321 of dam body 132. The pyramidal bottom surface 1321 and the inclined side surfaces enable dam body 132 to better distribute and resist shear forces when bearing them, making the overall structure of the pyramidal dam body 132 more stable, reducing the possibility of shear deformation, and providing strong shear resistance. In this way, when the rock (such as overburden) of the roof 120 collapses, the apex 1322 of the dam body 132 supports the collapsed roof 120, and the inclined side surface between the apex 1322 and the bottom surface 1321 of the dam body 132 supports the collapsed roof 120, so that the shear force can be more evenly distributed on the bottom surface 1321, thereby reducing the phenomenon of local stress concentration. The inclined side surfaces of the pyramid structure provide good support and stability, further enhancing the shear resistance of the dam body 132, and thus can mitigate the impact of the collapse of the overburden on the water. Therefore, the apex 1322 of the dam body 132 of the pyramid structure and the inclined surface can mitigate the impact of the rock collapse on the water in the water storage area 140, thereby mitigating the shear effect of water on the coal pillar dam body 111, which is beneficial to improving the stability and reliability of the coal pillar dam body 111 and improving the reliability of the coal mine underground water reservoir 100.

[0033] Anchor rods 133 are installed through the dam foundation 131, with their ends fixed to the base plate 150 and the dam body 132, respectively. The provision of anchor rods 133 reliably secures the structure 130 to the base plate 150, improving the reliability and stability of the connection between the structure 130 and the base plate 150. This reduces the likelihood of rock collapse damaging or dislodging the dam body 132 and the entire structure 130, thereby improving the overall strength and reliability of the structure 130. The number of anchor rods 133 can be one, two, or more, and can be appropriately determined based on the size and strength of the anchor rods 133, as well as the dimensions of the dam foundation 131 and the dam body 132. It is understood that the greater the number of anchor rods 133, the more reliable and stable the connection between the structure 130 and the base plate 150, and the greater the strength and reliability of the structure 130 itself.

[0034] There are multiple structures 130, which are arranged at intervals within the goaf 101. In this way, when the roof 120 in different areas collapses, there will be structures 130 to support the collapsed roof 120, thereby reducing the impact of the rock collapse of the roof 120 on the water in the coal mine underground water reservoir 100, slowing down the shearing effect of the water on the coal pillar dam 111, and improving the reliability of the coal pillar dam 111. At the same time, since the horizontal impact force of the water is transmitted step by step from the collapse point of the rock collapse in the water to the distance, by providing multiple structures 130, the horizontal impact of the water can be gradually slowed down, further reducing the shearing effect of the water on the coal pillar dam 111.

[0035] Specifically, multiple structures 130 can be set up in areas of the goaf 101 where roof 120 collapse is likely to occur, or multiple structures 130 can be set up in a preset area of the goaf 101. For example, the preset area can be an area within the goaf 101 that is 180m to 120m away from the coal pillar dam 11. It is understood that there is coal gangue in the goaf 101. Before constructing the structures 130, the gangue in the preset area can be cleaned up to lay a foundation for the construction of the structures 130.

[0036] Among them, Figure 2 As shown, the reservoir dam body 110 includes a coal pillar dam body 111, which can be formed by the surrounding side of the goaf 101. It can be understood that the reservoir dam body 110 can also include an artificial dam body 112, which is connected to the coal pillar dam body 111, and at least part of the artificial dam body 112 is located on the side of the reservoir dam body 110 adjacent to the working face.

[0037] like Figure 2As shown, specifically, the coal pillar dam 111 may include a first coal pillar dam 1111 and a second coal pillar dam 1112. The first coal pillar dam 1111 is a coal pillar adjacent to the working face, and the second coal pillar dam 1112 is a coal pillar not adjacent to the working face. At least part of the artificial dam 112 is located on the side of the reservoir dam 110 adjacent to the working face. This part of the artificial dam 112 may be connected to the first coal pillar dam 1111. For example, at least part of the artificial dam 112 may be arranged in the middle of the first coal pillar dam 1111 to connect the two adjacent parts of the first coal pillar dam 1111. Alternatively, at least part of the artificial dam 112 may be arranged at the end of the first coal pillar dam 1111 to connect the first coal pillar dam 1111 and the second coal pillar dam 1112. Specifically, at least part of the first coal pillar dam 1111 is adjacent to the working face. In this way, when the working face forms a goaf 101 again, the first coal pillar dam 1111 and the artificial dam 112 on the side adjacent to the working face are located between the two goafs 101. The artificial dam 112 on the side adjacent to the working face is configured to connect or isolate the two adjacent goafs 101. In this way, structures 130 can be set up in both adjacent goafs 101, and the two goafs 101 can be connected by the artificial dam 112 on the side adjacent to the working face, thereby increasing the range of the water storage area 140 and expanding the water storage capacity. Figure 1 As shown, in the coal mine underground water reservoir 100' in the related art, no artificial dam body 112' is set on the side adjacent to the working face. For example, the artificial dam body 112' is located on the side of the reservoir dam body that is not adjacent to the working face, and the artificial dam body 112' is located on the adjacent side of the first coal pillar dam body 1111' adjacent to the working face. The artificial dam body 112' is connected to the second coal pillar dam body 1112' that is not adjacent to the working face, and does not have the function of connecting the two adjacent goafs. Therefore, the present application reasonably sets the position of part of the artificial dam body 112, sets at least part of the artificial dam body 112 adjacent to the working face, and connects it to the first coal pillar dam body 1111 adjacent to the working face, so that the artificial dam body 112 on the side adjacent to the working face can connect the two adjacent goafs 101, so as to facilitate the increase of the water storage space of the coal mine underground water reservoir 100 and improve the water storage capacity.

[0038] Furthermore, if Figure 2As shown, the reservoir dam body 110 further includes a strike protection coal pillar 113 located within the water storage area 140. The strike protection coal pillar 113 is located between the two parts of the first coal pillar dam body 1111 adjacent to the working face, and extends along the advancing direction of the working face of the original coal seam mining, that is, the strike protection coal pillar 113 extends longitudinally to support the roof 120 within the water storage area 140. An artificial dam body 112 may also be provided between the strike protection coal pillars 113, that is, part of the artificial dam body 112 extends longitudinally to connect the two adjacent strike protection coal pillars 113. It is understandable that the artificial dam body 112 connecting the strike protection coal pillars 113 can connect or isolate the water storage areas on both sides of the strike protection coal pillars 113.

[0039] like Figure 3 As shown, in some possible embodiments provided in the present application, the dam foundation 131 includes an outer shell 1311 and a non-Newtonian fluid filling material 1312 filled inside the outer shell 1311 , and the outer shell 1311 and the dam body 132 are cast by concrete.

[0040] Among them, the non-Newtonian fluid filling material 1312 filled inside the outer shell 1311 can reduce the vertical impact of rock collapse on the roof 120, thereby greatly slowing down the impact of overburden collapse on water, and then slowing down the shear effect of water on the coal pillar dam 111, thereby improving the reliability and stability of the coal pillar dam 111.

[0041] Non-Newtonian fluids are fluids that do not satisfy Newton's experimental law of viscosity, that is, fluids whose shear stress and shear strain rate are not linearly related. Specifically, concentrated solutions and suspensions of polymers are generally non-Newtonian fluids. Examples include polyethylene, polyacrylamide, polyvinyl chloride, nylon 6, PVS, celluloid, polyester, rubber solutions, various engineering plastics, and chemical fiber melts and solutions. Petroleum, mud, coal-water slurry, ceramic slurry, paper pulp, drilling fluids and completion fluids, magnetic slurries, high-sand-laden water flows, debris flows, and the Earth's mantle are also non-Newtonian fluids.

[0042] The outer shell 1311 and the dam body 132 are cast with concrete, which is convenient and easy to implement, and is conducive to improving the reliability of the entire structure 130 .

[0043] In some possible embodiments provided herein, non-Newtonian fluid filling material 1312 comprises a shear-thickening non-Newtonian fluid. In actual production, the thickening non-Newtonian fluid can be a shear-thickening cement slurry. For example, by adding carbon nanotubes or a carbon nanotube / polyvinyl alcohol mixture to the cement slurry, the cement slurry exhibits a significant shear-thickening effect when subjected to impact. This can further reduce the impact of rockfall on the roof 120, thereby significantly mitigating the impact of rockfall on water.

[0044] like Figure 2 As shown, in some possible embodiments provided in the present application, a plurality of structures 130 are arranged in rows in the goaf 101 , and two adjacent rows of structures 130 are arranged in a staggered manner.

[0045] Since the impact force of water in the horizontal direction is transmitted step by step from the collapse point of the rock into the water to the distance, the staggered distribution of multiple structures 130 can gradually slow down the impact of water in the horizontal direction. In other words, the farther away from the rock collapse point, the weaker the impact of water. Therefore, the shearing effect of water on the coal pillar dam body 111 can be reduced.

[0046] That is, the coal mine underground water reservoir 100 provided in the embodiment of the present application mitigates the shear impact of water on the coal pillar dam 111 caused by rock collapse of the roof 120 by rationally setting the shape of the structure 130, the material of the structure 130, and the arrangement of multiple structures 130 in the following three aspects. First, the dam body 132 of the structure 130 is a pyramid structure, and the apex of the pyramid structure provides support for the collapsed roof 120. Second, by providing a non-Newtonian fluid material within the dam base 131 of the structure 130, the impact of the collapse of the roof 120 can be reduced, thereby greatly mitigating the impact of the collapse of the overburden on the water, and further mitigating the shear effect of the water on the coal pillar dam 111. Third, the staggered distribution of multiple structures 130 can gradually mitigate the impact of water in the horizontal direction. The farther away from the collapse point, the weaker the impact of the water, thereby reducing the shear effect of water on the coal pillar dam 111.

[0047] like Figure 2 As shown in some possible embodiments provided by the present application, the distance between two adjacent structures 130 in the same row is 13m to 17m, and the distance between two adjacent rows of structures 130 is 18m to 22m. Figure 2 As shown in D1 in FIG, the spacing between two adjacent rows of structures 130 is as follows Figure 2 Specifically, the distance between two adjacent structures 130 in the same row may be 15 m, and the distance between two adjacent rows of structures 130 may be 20 m.

[0048] In this embodiment, by properly setting the spacing D1 between two adjacent structures 130 in the same row, and properly setting the spacing D2 between two adjacent rows of structures 130, multiple structures 130 can be relatively evenly distributed in areas where the roof 120 is prone to collapse. This allows roofs 120 at different locations to be supported by the structures 130 at corresponding locations after collapse, thereby providing a good buffering effect, mitigating the impact of overburden collapse on water, and thereby mitigating the shearing effect of water on the coal pillar dam 111. Furthermore, by properly setting the distance between two adjacent structures 130 in the same row, and properly setting the distance between two adjacent rows of structures 130, the impact of water in the horizontal direction can be gradually mitigated, further reducing the shearing effect of water on the coal pillar dam 111.

[0049] Specifically, the distance D1 between two adjacent structures 130 in the same row is 13m, 14m, 15m, 16m, 17m, or other sizes. The distance D2 between two adjacent rows of structures 130 is 18m, 19m, 20m, 21m, 22m, or other sizes.

[0050] In the above embodiment, the same row of structures 130 extends in the horizontal direction, and multiple rows of structures 130 are spaced apart in the vertical direction, which is parallel to the advancing direction of the working face of coal seam mining. In other words, the advancing direction of the working face of the original coal seam mining corresponding to the goaf 101 is marked as the vertical direction, and the direction perpendicular to the advancing direction of the original working face is marked as the horizontal direction, such as Figure 2 As shown, the longitudinal direction is indicated by arrow Y, and the transverse direction is indicated by arrow X. The plurality of structures 130 are arranged in a plurality of rows spaced apart in the longitudinal direction. Each row comprises a plurality of structures 130 spaced apart in the transverse direction, and there is a certain transverse offset distance between adjacent rows of structures 130, so that the adjacent rows of structures 130 are staggered.

[0051] like Figure 3 As shown, in some possible embodiments provided by this application, the outer shell 1311 of the dam base 131 is a rectangular box structure, and the dam body 132 is a regular tetrahedron structure. The outer shell 1311 of the dam base 131 with a rectangular box structure and the dam body 132 with a regular tetrahedron structure are easy to process and implement.

[0052] The dam body 132, a regular tetrahedron structure, has a special geometric shape, such as a square bottom 1321 and isosceles triangle sides. This structure allows it to better distribute and resist shear forces when subjected to them. The square bottom 1321 and isosceles triangle sides make the overall structure more stable, reducing the possibility of shear deformation, thereby mitigating the impact of overburden collapse on water. Furthermore, since the projection of the vertex 1322 of the regular tetrahedron structure onto the bottom 1321 is the center of the bottom 1321, this means that when subjected to shear forces, the shear forces can be more evenly distributed on the bottom 1321, thereby reducing local stress concentration. Furthermore, the isosceles triangle sides provide good support and stability, further enhancing the structure's shear resistance, thereby mitigating the impact of overburden collapse on water.

[0053] like Figure 4 As shown, in some possible embodiments provided by the present application, the vertex 1322 of the dam body 132 is higher than the liquid level of the water storage area 140, and the height difference between the vertex 1322 of the dam body 132 and the liquid level of the water storage area 140 is greater than or equal to 0.2m, so that the rock that collapses from the roof 120 falls into the liquid level of the water storage area 140 after being supported by the vertex 1322 of the dam body 132 and the inclined side of the dam body 132. This ensures that the dam body 132 of the structure 130 can reliably mitigate the impact of the rock collapse from the roof 120 on the water, thereby mitigating the shear effect of the water on the coal pillar dam body 111, which is beneficial to improving the stability and reliability of the coal pillar dam body 111 and improving the reliability of the coal mine underground water reservoir 100. Figure 4 The dotted line L in the figure represents the liquid level of the water storage area 140. The height difference between the vertex 1322 of the dam body 132 and the liquid level L of the water storage area 140 is shown as follows: Figure 4 As shown in H.

[0054] In other words, the height of the dam body 132 of the structure 130 depends on the amount of water in the water storage area 140. Specifically, the apex 1322 of the dam body 132 should be 0.2 m or higher than the liquid level of the coal mine underground water reservoir 100 when it is stored. Specifically, H can be 0.2 m, 0.25 m, 0.3 m, 0.35 m, or other dimensions. It is understood that for the same liquid level, the higher the height H, the larger the volume of the structure 130, the more materials used, and the higher the cost. Therefore, by rationally setting the difference between the apex 1322 of the dam body 132 and the liquid level of the water storage area 140 to 0.2 m, the volume of the structure 130 can be significantly reduced, saving costs, while ensuring that the dam body 132 of the structure 130 has good shear resistance and can reliably mitigate the impact of overburden collapse on water.

[0055] In some possible embodiments provided in the present application, the coal mine underground water reservoir 100 further includes: a liquid conveying device, which is connected to the water storage area 140 and is used to extract or recharge the liquid in the water storage area 140.

[0056] By setting up a liquid conveying device, water from other areas can be transported to the water storage area 140 of the coal mine underground water reservoir 100 for storage, and the water stored in the coal mine underground water reservoir 100 can also be transported to other locations. In this way, the liquid in the water storage area 140 can be extracted or recharged, thereby achieving water supply or water level adjustment to facilitate the transportation of water in the coal mine underground water reservoir 100.

[0057] In some possible embodiments provided in the present application, the coal mine underground water reservoir 100 also includes multiple stress detection devices and sandbags. The multiple stress detection devices are arranged at intervals on the coal pillar dam 111. The stress detection devices are used to detect the stress of the coal pillar dam 111 at relative positions. The sandbags are arranged in a protection area of the coal pillar dam 111. The protection area includes at least the area of the coal pillar dam 111 corresponding to the stress detection device with abnormal detection values.

[0058] Among them, the detection value of the stress detection device is abnormal, indicating that the stress of the coal pillar dam 111 at the relative position is concentrated, that is, the stress detection device can determine the stress concentration area of the coal pillar dam 111, and then arrange sandbags in the stress concentration area of the coal pillar dam 111 to reinforce the coal pillar dam 111, thereby helping to improve the reliability of the coal pillar dam 111 and improve the reliability of the coal mine underground water reservoir 100.

[0059] like Figure 5 As shown, an embodiment of the second aspect of the present application proposes a construction method of a coal mine underground water reservoir 100, which is used to construct the coal mine underground water reservoir 100 of any of the aforementioned embodiments, and includes the following method steps.

[0060] Step 501: Pre-processing the goaf formed after coal seam mining.

[0061] Among them, by performing pre-treatment operations on the goaf 101 formed after coal seam mining, a construction site is provided for the construction of the structure 130, laying a foundation for the construction of the structure 130.

[0062] Step 502: Carry out structure construction, wherein the steps of carrying out structure construction include: constructing the outer shell of the dam foundation in the goaf after the pretreatment operation, passing the first end of the anchor rod through the outer shell and fixing it to the bottom plate below the goaf, pouring non-Newtonian fluid filling material into the outer shell, constructing the dam body, and fixing the second end of the anchor rod, the dam body is a pyramid structure, the bottom surface of the pyramid structure is connected to the dam foundation, and the top of the pyramid structure faces the top plate above the goaf.

[0063] Concreting the outer shell 1311 of the dam foundation 131 and the dam body 132 helps improve the strength of the structure 130. The first end of the anchor rod 133 passes through the interior of the outer shell 1311 of the dam foundation 131 and is fixed to the rock of the bottom plate 150. The second end of the anchor rod 133 is fixed to the dam body 132. This reliably secures the structure 130 to the bottom plate 150 and improves the overall strength and reliability of the structure 130. The non-Newtonian fluid filling material 1312 filled within the outer shell 1311 of the dam foundation 131 can reduce the impact of rock collapse on the roof 120, thereby significantly mitigating the impact of overburden collapse on water, and further reducing the shear effect of water on the coal pillar dam body 111.

[0064] By configuring the dam body 132 as a pyramidal structure, with the bottom surface 1321 of the pyramidal structure connected to the dam foundation 131 and the apex 1322 of the pyramidal structure facing the top plate 120, it can be understood that an inclined side surface connects the apex 1322 and the bottom surface 1321 of the dam body 132. The pyramidal structure's bottom surface 1321 and the inclined side surfaces enable it to better distribute and resist shear forces when bearing them, making the overall structure of the pyramidal dam body 132 more stable, reducing the possibility of shear deformation, and providing stronger shear resistance. In this way, when the rock (such as overburden) of the roof 120 collapses, the vertex 1322 of the dam body 132 can support the collapsed roof 120, and the inclined side surface between the vertex 1322 and the bottom surface 1321 of the dam body 132 can support the collapsed roof 120, so that the shear force can be more evenly distributed on the bottom surface 1321, thereby reducing the phenomenon of local stress concentration. The inclined side surface provides good support and stability, further enhancing the shear resistance of the structure, and thus can slow down the impact of the collapse of the overburden on the water. Therefore, the vertex 1322 of the dam body 132 and the inclined surface can slow down the impact of the rock collapse on the water in the water storage area 140, and thus slow down the shear effect of water on the coal pillar dam body 111, which is beneficial to improving the reliability of the coal pillar dam body 111 and improving the reliability of the coal mine underground water reservoir 100.

[0065] Step 503: performing sandbag protection operations, wherein the steps of performing sandbag protection operations include: deploying stress detection devices at different positions of the coal pillar dam, and placing sandbags in areas of the coal pillar dam corresponding to stress detection devices with abnormal detection values.

[0066] Among them, the detection value of the stress detection device is abnormal, indicating that the stress of the coal pillar dam 111 at the relative position is concentrated, that is, the stress detection device can determine the stress concentration area of the coal pillar dam 111, and then arrange sandbags in the stress concentration area of the coal pillar dam 111 to reinforce the coal pillar dam 111, thereby helping to improve the reliability of the coal pillar dam 111 and improve the reliability of the coal mine underground water reservoir 100.

[0067] In some possible embodiments provided in the present application, a dam foundation shell is constructed in a goaf after pretreatment, a first end of an anchor rod is passed through the shell and fixed to the bottom plate below the goaf, a non-Newtonian fluid filling material is poured into the shell, a dam body is constructed, and the second end of the anchor rod is fixed. The dam body is a pyramid structure, the bottom surface of the pyramid structure is connected to the dam foundation, and the apex of the pyramid structure faces the roof above the goaf. The steps specifically include:

[0068] After the pretreatment operation, the side walls 1313 of the outer shell 1311 of the dam foundation 131 are cast with concrete in the goaf 101, and a number of anchor rods 133 are driven into the rock formation of the bottom plate 150 to fix the shear protection structure 130. The height of the anchor rods 133 needs to be higher than the height of the dam foundation 131 so as to be connected to the dam body 132. The anchor rods 133 are accommodated in the space enclosed by the side walls 1313; the bottom wall 1314 of the outer shell 1311 of the dam foundation 131 is constructed to prevent the non-Newtonian fluid that acts as a buffer from penetrating into the rock formation of the bottom plate 150. A non-Newtonian fluid filling material 1312 is poured into the inner cavity of the outer shell 1311 of the dam foundation 131; the top wall 1315 of the outer shell 1311 of the dam foundation 131 is constructed, and the dam body 132 is constructed on the top wall 1315 of the outer shell 1311 of the dam foundation 131, such as by pouring concrete on the top wall 1315 of the outer shell 1311 of the dam foundation 131, thereby completing the construction of the structure 130.

[0069] It is understandable that, through step 502 , a plurality of structures 130 may be constructed, and the plurality of structures 130 are arranged in rows and spaced apart in the goaf 101 , and two adjacent rows of structures 130 are arranged in a staggered manner.

[0070] In some possible embodiments provided in the present application, the construction method of the coal mine underground water reservoir also includes: constructing an artificial dam body, which is located on the side of the reservoir dam body adjacent to the working face and is configured to connect two adjacent goafs; wherein, before the step of constructing the artificial dam body, it also includes: using a liquid conveying device to extract the liquid in the goaf where the liquid is stored; and / or performing pretreatment operations on the goaf formed after coal seam mining, performing structure construction, and performing sandbag protection operations.

[0071] In this embodiment, by constructing an artificial dam body 112, the artificial dam body 112 is used to connect the adjacent goaf areas 101, thereby expanding the water storage space of the underground reservoir and increasing the water storage capacity. Specifically, the artificial dam body 112 is located on the side of the reservoir dam body 110 adjacent to the working face, that is, the artificial dam body 112 is connected to the first coal pillar dam body 1111 mentioned above. The two goaf areas 101 can be understood as the goaf areas 101 with structures 130 constructed, that is, the goaf areas 101 corresponding to the coal mine underground water reservoir 100, and the goaf areas 101 adjacent to the goaf areas 101 without structures 130 constructed thereon. The goaf areas 101 without structures 130 constructed thereon can be understood as the goaf areas 101 formed by subsequent continued coal mining, and the goaf areas 101 are adjacent to the working face. The artificial dam 112 can connect the goaf 101 where the structure 130 is constructed with the goaf 101 of the adjacent working face where the structure 130 is not constructed.

[0072] Specifically, if the mining of the adjacent working face is completed, a new goaf 101 without the construction of the structure 130 is formed. At this time, the water in the coal mine underground water reservoir 100 with the construction of the structure 130 can be temporarily pumped out and transferred using a liquid conveying device. After all the water in the coal mine underground water reservoir 100 is transferred, an artificial dam body 112 can be set on the side of the coal mine underground water reservoir 100 adjacent to the working face. The artificial dam body 112 is used to connect the coal mine underground water reservoir 100 with the goaf 101 adjacent to the working face without the construction of the structure 130, and the goaf 101 adjacent to the working face is pre-treated, the structure 130 is constructed, and the sandbag protection operation is performed, that is, steps 501, 502, and 503 are repeated. Then, water can be stored by using a liquid conveying device to transport water to the water storage area 140. It can be understood that in this case, the scope of the coal mine underground water reservoir 100 is the water storage area 140 of the two goafs 101, thereby expanding the underground water reservoir storage space and increasing the water storage capacity.

[0073] It can be understood that the steps of performing pretreatment operations, constructing structures 130, and performing sandbag protection operations on the goaf 101 formed after coal seam mining without the construction of structures 130 can also be performed before the step of setting an artificial dam body 112 between the coal pillar dam bodies 111, that is, after the steps of performing pretreatment operations, constructing structures 130, and performing sandbag protection operations on the goaf 101 without the construction of structures 130, the step of constructing the artificial dam body 112 can be performed to connect the two goaf areas 101.

[0074] In some possible embodiments provided in the present application, the steps of performing pre-processing operations on the goaf formed after coal seam mining include: cleaning the coal gangue in the goaf at a preset distance from the coal pillar dam 111, where the preset distance is 80m to 120m.

[0075] That is, before construction of structure 130 begins, gangue within a range of 80 to 120 meters between goaf 101 and coal pillar dam 111 is cleared to lay the foundation for the construction of shear-resistant structure 130. It is understood that if the collapse distance of roof 120 in goaf 101 is short or construction difficulties arise, the range of gangue clearing can be appropriately changed.

[0076] In the description of the present invention, the term "plurality" refers to two or more than two. Unless otherwise expressly defined, the orientation or positional relationship indicated by the terms "upper" and "lower" is based on the orientation or positional relationship described in the accompanying drawings. It is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it cannot be understood as a limitation on the present invention. The terms "connection", "installation", "fixed", etc. should be understood in a broad sense. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection or an indirect connection through an intermediate medium. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to the specific circumstances.

[0077] In the description of the present invention, the description of the terms "one embodiment", "some embodiments", "specific embodiments", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In the present invention, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in a suitable manner in any one or more embodiments or examples. 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 can have various changes and variations. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A coal mine underground reservoir, characterized in that: include: A reservoir dam body is located on the periphery of the goaf after coal seam mining, and the reservoir dam body includes a coal pillar dam body formed around the goaf; a roof located above the goaf; A bottom plate is located below the goaf, and the reservoir dam body, the top plate, and the bottom plate together form a water storage area; a structure arranged in the water storage area, comprising a dam foundation, a dam body, and anchor rods, wherein the bottom of the dam foundation is connected to the bottom plate, the dam body is arranged on the top of the dam foundation, and the anchor rods are arranged through the dam foundation to connect the bottom plate and the dam body; The dam foundation includes an outer shell, which is a rectangular box structure. The dam body is a pyramid structure, which is a regular quadrangular pyramid structure. The bottom surface of the pyramid structure is connected to the dam foundation, and the vertex of the pyramid structure faces the top plate.

2. The coal mine underground water reservoir according to claim 1, characterized in that: The dam foundation further includes a non-Newtonian fluid filling material filled in the shell, the shell and the dam body are cast in concrete, and / or, The number of the anchor rod is at least one.

3. The coal mine underground water reservoir according to claim 2, characterized in that: The non-Newtonian fluid filling material includes a shear thickening non-Newtonian fluid.

4. The coal mine underground water reservoir according to claim 1, characterized in that: A plurality of the structures are arranged in rows in the goaf, and the structures in two adjacent rows are arranged in a staggered manner.

5. The coal mine underground water reservoir according to claim 4, characterized in that: The distance between two adjacent structures in the same row is 13m to 17m; The distance between two adjacent rows of the said structures is 18m to 22m; The structures in the same row are distributed at intervals in the transverse direction, and multiple rows of the structures are distributed at intervals in the longitudinal direction, which is parallel to the advancing direction of the working face of coal seam mining.

6. The coal mine underground water reservoir according to claim 1, characterized in that: The top of the dam body is higher than the liquid level of the water storage area, and the height difference between the top of the dam body and the liquid level of the water storage area is greater than or equal to 0.2m.

7. The coal mine underground water reservoir according to claim 1, characterized in that: Also includes: a liquid conveying device, the liquid conveying device being in communication with the water storage area and being used for extracting or recharging the liquid in the water storage area; and / or, The reservoir dam body further comprises an artificial dam body connected to the coal pillar dam body, and at least a portion of the artificial dam body is located on a side of the reservoir dam body adjacent to the working face.

8. The coal mine underground water reservoir according to claim 1, characterized in that: The coal mine underground water reservoir also includes multiple stress detection devices and sandbags. The multiple stress detection devices are arranged at intervals on the coal pillar dam. The stress detection devices are used to detect the stress of the coal pillar dam at relative positions. The sandbags are arranged in a protection area of the coal pillar dam. The protection area includes the area of the coal pillar dam corresponding to the stress detection device with abnormal detection values.

9. A method for constructing an underground water reservoir in a coal mine, characterized in that: The method for constructing a coal mine underground water reservoir according to any one of claims 1 to 8 comprises: Carry out pre-treatment operations on the goaf formed after coal seam mining; Performing structure construction, wherein the steps of performing structure construction include: constructing a shell of a dam foundation in the goaf after the pretreatment operation, passing the first end of an anchor rod through the shell and fixing it to the bottom plate below the goaf, pouring non-Newtonian fluid filling material into the shell, constructing a dam body, and fixing the second end of the anchor rod, wherein the dam body is a pyramid structure, the bottom surface of the pyramid structure is connected to the dam foundation, and the apex of the pyramid structure faces the top plate above the goaf; Perform sandbag protection operations, wherein the steps of performing sandbag protection operations include: deploying stress detection devices at different positions of the coal pillar dam body, and arranging the sandbags in the areas of the coal pillar dam body corresponding to the stress detection devices with abnormal detection values.

10. The method for constructing a coal mine underground reservoir according to claim 9, characterized in that: Also includes: constructing an artificial dam body, wherein at least a portion of the artificial dam body is located on a side of the reservoir dam body adjacent to the working face and is configured to connect two adjacent goaf areas; Wherein, before the step of constructing the artificial dam body, the method further includes: Using a liquid conveying device to extract the liquid in the goaf where the liquid is stored; and / or The steps of performing the pretreatment operation, the structure construction, and the sandbag protection operation on the goaf formed after coal seam mining.

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