Plant root irrigation method in coal mining subsidence area

Abstract

The application provides a coal mining subsidence area plant root irrigation method, which comprises the following steps: obtaining a buried depth parameter of a phreatic aquifer in a coal mining subsidence area, determining an irrigation depth according to the buried depth parameter of the phreatic aquifer; determining an irrigation influence radius; determining a drilling scheme in the phreatic aquifer according to the irrigation depth, the irrigation influence radius and the terrain undulation of the coal mining subsidence area, and obtaining a directional drilling according to the drilling scheme; and penetrating an irrigation pipeline into the directional drilling, and performing irrigation through the irrigation pipeline. Through the technical scheme provided in the application, the problem that the artificial irrigation mode in the related art cannot meet the irrigation requirement can be solved.

Description

Technical Field

[0001] The present invention relates to the technical field of coal mining subsidence area treatment, and in particular to a method for irrigating plant roots in coal mining subsidence areas. Background Art

[0002] During coal mining, some mining areas have shallow coal resources, resulting in severe ground subsidence after mining. This is especially true in ultra-wide working faces, where large mining subsidence areas form along the working face after mining. Deep cracks develop along the edges of these areas, creating pathways for water to flow into the mine. It typically takes three to five years for these areas to stabilize and for groundwater to gradually return to its pre-mining state. Before this period, these areas become isolated water runoff islands, requiring surface vegetation to be maintained only through artificial irrigation, in addition to rainfall. Due to water shortages, surface vegetation in these areas is affected and showing signs of degradation.

[0003] In the relevant technology, there are mainly two ways of artificial irrigation in the subsidence area before the collapse stabilizes. The first is to transport water to the destination by water pumps or water tankers, and maintain the vegetation by flooding or spraying. This method has the problems of serious waste of water resources, low irrigation efficiency, and the inability of plant roots to penetrate deep into the soil layer. The second is to bury pipes in the soil layer of the coal mining subsidence area to directly irrigate the roots of vegetation. However, this method requires manual trenching when burying the pipes, which is a large amount of work and will cause secondary damage to the already fragile ecological environment.

[0004] Therefore, the artificial irrigation method in the subsidence area in the related art has the problem of being unable to meet the irrigation needs. Summary of the Invention

[0005] The present invention provides a method for irrigating plant roots in a coal mining subsidence area, so as to solve the problem that the artificial irrigation method in the subsidence area in the related art cannot meet the irrigation demand.

[0006] The present invention provides a method for irrigating plant roots in a coal mining subsidence area. The method for irrigating plant roots in a coal mining subsidence area includes: obtaining the burial depth parameters of a phreatic aquifer in the coal mining subsidence area, and determining the irrigation depth according to the burial depth parameters of the phreatic aquifer; determining the irrigation influence radius; determining a drilling plan in the phreatic aquifer according to the irrigation depth, the irrigation influence radius, and the topography of the coal mining subsidence area, and obtaining a directional borehole according to the drilling plan; inserting an irrigation pipeline into the directional borehole, and irrigating through the irrigation pipeline.

[0007] Furthermore, the step of irrigating through the irrigation pipeline includes: detecting the moisture content within a range of an irrigation influence radius at a distance from the irrigation pipeline, and controlling the working state of the irrigation pipeline according to the moisture content.

[0008] Furthermore, the step of determining the irrigation influence radius includes: constructing a first borehole in the coal mining subsidence area, the first borehole penetrates the phreatic aquifer and terminates after drilling to the upper part of the impermeable layer of the coal mining subsidence area to obtain an injection hole; constructing multiple second boreholes at equal intervals on the same side of the injection hole and in a direction away from the injection hole, the second boreholes are drilled to the upper part of the phreatic aquifer to obtain multiple observation holes; injecting water into the injection hole at a preset pressure for a preset time, and after the water injection is completed, obtaining the soil moisture content change value at a preset depth of the observation hole, and determining the irrigation influence radius based on the soil moisture content change value.

[0009] Furthermore, the step of constructing a first borehole in the coal mining subsidence area includes: obtaining the average soil layer thickness in the coal mining subsidence area; obtaining the water injection hole drilling position, the soil layer thickness at the water injection hole drilling position is equal to the average soil layer thickness; constructing a first borehole at the water injection hole drilling position to obtain a water injection hole.

[0010] Furthermore, the step of determining the irrigation influence radius according to the soil moisture change value includes: setting the farthest distance between the observation hole and the water injection hole where the soil moisture change value exceeds a preset threshold as the irrigation influence radius.

[0011] Furthermore, the steps of obtaining the burial depth parameters of the phreatic aquifer in the coal mining subsidence area and determining the irrigation depth according to the burial depth parameters of the phreatic aquifer include: evenly arranging multiple survey points in the coal mining subsidence area, and statistically analyzing the burial depth parameters of the phreatic aquifer at the survey points; determining the depth of the upper part of the phreatic aquifer according to the burial depth parameters of the phreatic aquifer; and setting the depth of the upper part of the phreatic aquifer as the irrigation depth.

[0012] Furthermore, the steps of determining a drilling plan in the phreatic aquifer based on the irrigation depth, the irrigation influence radius and the topographic relief of the coal mining subsidence area, and obtaining a directional drilling plan based on the drilling plan include: dividing the coal mining subsidence area into a plurality of strip areas based on the irrigation influence radius and the maximum drilling capacity of the drilling rig, and obtaining a plane drilling plan based on the shape of the strip area and the irrigation influence radius; performing terrain elevation profile mapping of the coal mining subsidence area along the extension direction of the strip area to obtain the topographic relief, and obtaining a profile drilling plan based on the topographic relief and the irrigation depth; obtaining a drilling plan based on the plane drilling plan and the profile drilling plan; and obtaining a directional drilling plan based on the drilling plan.

[0013] Furthermore, the step of inserting the irrigation pipeline into the directional borehole includes: before the drilling rig reaches its maximum drilling capacity, the drill bit of the drilling rig is penetrated out of the ground and the irrigation pipeline is connected to the drill bit; the drilling rig performs a drill withdrawal operation, and utilizes the dragging effect of the drill bit to lay the irrigation pipeline in the directional borehole.

[0014] Furthermore, the steps of inserting an irrigation pipeline into a directional borehole and irrigating through the irrigation pipeline include: the irrigation pipeline includes multiple irrigation branches, and multiple moisture observation devices are arranged at intervals along the extension direction of each irrigation branch, and the moisture content of the soil layer in the coal mining subsidence area is obtained through the multiple moisture observation devices; the steps of detecting the moisture content within the range of the irrigation influence radius from the irrigation pipeline, and controlling the working state of the irrigation pipeline according to the moisture content include: when the moisture content within the range of the irrigation influence radius from the irrigation branch reaches the irrigation requirement, stopping the water supply of the irrigation branch.

[0015] Furthermore, the diameter of the irrigation branch pipe is set to be less than or equal to 1 / 2 of the aperture of the directional drilling hole; and / or, the irrigation pipeline also includes a water supply pipe, the first ends of the multiple irrigation branch pipes are connected to the water supply pipe, the first ends of the multiple irrigation branch pipes are provided with a first valve body, and the second ends of the multiple irrigation branch pipes are provided with a second valve body, the water supply of the irrigation branch pipe is controlled by the first valve body, and after sand enters the irrigation branch pipe, the sand is cleared by opening the second valve body.

[0016] By applying the technical solution of the present invention, firstly, the irrigation depth of the coal mining subsidence area is determined according to the buried depth parameters of the phreatic aquifer in the coal mining subsidence area, and the drilling scheme in the phreatic aquifer in the coal mining subsidence area is determined according to the irrigation depth, irrigation influence radius and terrain undulation of the coal mining subsidence area. Compared with the irrigation methods of sprinkler irrigation or flood irrigation, irrigation can be carried out according to the specific conditions of the coal mining subsidence area, so as to improve the utilization rate of water resources in the irrigation process and improve irrigation efficiency; secondly, a directional borehole is obtained according to the drilling scheme. Since the directional borehole is located in the phreatic aquifer, compared with drilling in the soil layer, damage to the soil layer and the phreatic aquifer can be avoided. Secondary damage is caused to the plant roots in the soil layer; finally, the water level of the submerged aquifer is restored by passing an irrigation pipeline through the directional borehole, so that the submerged aquifer with restored water level can be used to supply water to the soil layer above it. Deep root water supply is adopted. Since the plant roots have a tendency to move towards water, the plant roots in the coal mining subsidence area grow downward, thereby improving the stress resistance and ecological stability of the vegetation in the coal mining subsidence area. In addition, by irrigating underground, the volatilization of water during the irrigation process can be reduced, thus avoiding the waste of water resources. The irrigation pipeline is buried underground to avoid the irrigation pipeline from being exposed to wind and rain, thus slowing down the aging rate of the irrigation pipeline. Therefore, the plant root irrigation method for coal mining subsidence area provided by the present invention can meet the irrigation needs of coal mining subsidence area. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The accompanying drawings, which constitute part of this application, are intended to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are intended to explain the present invention and do not constitute an undue limitation of the present invention. In the accompanying drawings:

[0018] Figure 1A flow chart of a method for irrigating plant roots in a coal mining subsidence area according to an embodiment of the present invention is shown;

[0019] Figure 2 A flow chart showing the steps of inserting an irrigation pipe into a directional drill hole and irrigating through the irrigation pipe in a method for irrigating plant roots in a coal mining subsidence area provided by an embodiment of the present invention;

[0020] Figure 3 A flow chart showing the steps of determining the irrigation influence radius of a plant root irrigation method in a coal mining subsidence area provided by an embodiment of the present invention;

[0021] Figure 4 A flow chart showing the steps of constructing a first borehole in a coal mining subsidence area according to a method for irrigating plant roots in a coal mining subsidence area provided by an embodiment of the present invention is shown;

[0022] Figure 5 A flowchart illustrating the steps of obtaining a depth parameter of a phreatic aquifer in a coal mining subsidence area and determining an irrigation depth based on the depth parameter of the phreatic aquifer is shown in the method for irrigating plant roots in a coal mining subsidence area provided by an embodiment of the present invention;

[0023] Figure 6 A flowchart illustrating the steps of determining a drilling plan within a phreatic aquifer based on the irrigation depth, the irrigation influence radius, and the topography of the coal mining subsidence area, and obtaining a directional drilling plan according to the drilling plan, according to a plant root irrigation method for a coal mining subsidence area provided by an embodiment of the present invention;

[0024] Figure 7 A schematic diagram showing a method for irrigating plant roots in a coal mining subsidence area according to an embodiment of the present invention is provided;

[0025] Figure 8 A schematic diagram of a planar drilling design for a plant root irrigation method in a coal mining subsidence area provided by an embodiment of the present invention is shown.

[0026] The above drawings include the following reference numerals:

[0027] 10. Coal mining subsidence area; 11. Phreatic aquifer; 12. Soil layer; 13. Aquiclude; 14. Strip area;

[0028] 20. Irrigation pipeline; 21. Irrigation branch pipe; 211. First valve body; 212. Second valve body; 22. Moisture content observation device; 23. Water supply pipe;

[0029] 31. Water injection hole; 32. Observation hole;

[0030] 40. Water supply station. DETAILED DESCRIPTION

[0031] The following will be combined with the accompanying drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, rather than all the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is in no way intended to limit the present invention and its application or use. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0032] like Figures 1 to 8 As shown, an embodiment of the present invention provides a method for irrigating plant roots in a coal mining subsidence area. The method for irrigating plant roots in a coal mining subsidence area includes:

[0033] S100, obtaining a depth parameter of a phreatic aquifer 11 in a coal mining subsidence area 10, and determining an irrigation depth according to the depth parameter of the phreatic aquifer 11;

[0034] S200, determining the irrigation impact radius;

[0035] S300, determining a drilling plan in the phreatic aquifer 11 according to the irrigation depth, the irrigation influence radius, and the topography of the coal mining subsidence area 10, and obtaining a directional drill hole according to the drilling plan;

[0036] S400 , inserting the irrigation pipe 20 into the directional drilled hole, and performing irrigation through the irrigation pipe 20 .

[0037] The plant root irrigation method in the coal mining subsidence area provided by this embodiment is applied. First, the irrigation depth of the coal mining subsidence area 10 is determined according to the burial depth parameters of the phreatic aquifer 11 in the coal mining subsidence area 10. The drilling scheme in the phreatic aquifer 11 in the coal mining subsidence area 10 is determined according to the irrigation depth, irrigation influence radius and terrain undulation of the coal mining subsidence area 10. Compared with the irrigation methods of sprinkler irrigation or flood irrigation, irrigation can be carried out according to the specific conditions of the coal mining subsidence area 10 to improve the utilization rate of water resources in the irrigation process and improve irrigation efficiency. Secondly, a directional borehole is obtained according to the drilling scheme. Since the directional borehole is located in the phreatic aquifer 11, compared with drilling in the soil layer 12, it can avoid soil damage. Finally, the water level of the submerged aquifer 11 is restored by passing an irrigation pipe 20 through the directional borehole, so that the submerged aquifer 11 with restored water level can be used to supply water to the soil layer 12 above it. Deep root water supply is adopted. Since the plant roots have a tendency to move towards water, the plant roots in the coal mining subsidence area 10 grow downward, thereby improving the stress resistance and ecological stability of the vegetation in the coal mining subsidence area 10. In addition, by irrigating underground, the volatilization of water during the irrigation process can be reduced, thus avoiding the waste of water resources. The irrigation pipe 20 is buried underground to prevent the irrigation pipe 20 from being exposed to wind and rain, thereby slowing down the aging rate of the irrigation pipe 20. Therefore, the plant root irrigation method for coal mining subsidence area provided by the present invention can meet the irrigation needs of coal mining subsidence area 10.

[0038] like Figure 7 As shown, the coal mining subsidence area 10 includes a soil layer 12, a phreatic aquifer 11 and an aquiclude 13 distributed in sequence from top to bottom in the vertical direction. After coal mining, the surface collapses severely, resulting in a large number of deep cracks developing at the edge of the coal mining subsidence area 10, causing the water level stored in the phreatic aquifer 11 to drop. The coal mining subsidence area 10 after the cracks have recovered and the plant root irrigation method of the coal mining subsidence area is selected to meet the irrigation needs of the coal mining subsidence area 10.

[0039] It should be noted that the burial depth parameters of the submerged aquifer 11 include the burial depth parameters of the top interface of the submerged aquifer 11 and the burial depth parameters of the bottom interface of the submerged aquifer 11. The burial depth parameter of the top interface of the submerged aquifer 11 refers to the distance between the top interface of the submerged aquifer and the top interface of the soil layer 12 in the vertical direction, and the burial depth parameter of the bottom interface of the submerged aquifer 11 refers to the distance between the bottom interface of the submerged aquifer 11 and the top interface of the soil layer 12 in the vertical direction; the irrigation depth refers to the distance between the drilling scheme and the top interface of the soil layer 12 in the vertical direction; the irrigation influence radius refers to the average distance between the edge of the range that can be irrigated by irrigating a certain point in the coal mining subsidence area and the irrigation point; the terrain undulation refers to the height distribution of the top interface of the soil layer 12 on the horizontal plane.

[0040] like Figure 2 As shown, the step S400 of irrigating through the irrigation pipe 20 includes:

[0041] S440: Detecting the water content within the range of the irrigation influence radius from the irrigation pipe 20, and controlling the operating state of the irrigation pipe 20 based on the water content. By detecting the water content within the range of the irrigation influence radius from the irrigation pipe 20, the irrigation status of the irrigation pipe 20 is reflected, and the operating state of the irrigation pipe 20 is controlled based on the water content, including controlling the irrigation pipe 20 to stop irrigation when the water content indicates that the irrigation pipe 20 has completed irrigation.

[0042] like Figure 3 As shown, step S200 of determining the irrigation impact radius includes:

[0043] S210, constructing a first borehole in the coal mining subsidence area 10, the first borehole penetrating the phreatic aquifer 11 and ending at the upper portion of the aquiclude 13 of the coal mining subsidence area 10, thereby forming a water injection hole 31;

[0044] S220, constructing a plurality of second boreholes at equal intervals on the same side of the water injection hole 31 and in a direction away from the water injection hole 31, wherein the second boreholes are drilled to the upper portion of the phreatic aquifer 11 to obtain a plurality of observation holes 32;

[0045] S230: Inject water into the water injection hole 31 at a preset pressure for a preset time. After the water injection is completed, obtain the soil moisture content change value at the preset depth of the observation hole 32, and determine the irrigation impact radius based on the soil moisture content change value. Because the water injection hole 31 extends vertically from the top interface of the soil layer 12 to the upper portion of the aquifer 13, injecting water into the water injection hole 31 at a preset pressure for a preset time can achieve an irrigation effect at a vertical distance from the soil layer 12 to the irrigation depth of the water injection hole 31. Because the observation hole 32 extends vertically from the top interface of the soil layer 12 to the upper portion of the submerged aquifer 11, the observation hole 32 can penetrate the soil layer 12, thereby enabling the soil moisture content change value of the soil layer 12 to be observed through the observation hole 32, and the irrigation impact radius is determined based on the soil moisture content change value.

[0046] It should be noted that the upper part of the aquiclude 13 refers to the part between the top interface of the aquiclude 13 and the point where the vertical distance from the bottom interface of the aquiclude 13 is two-thirds of the thickness of the aquiclude 13; the upper part of the phreatic aquifer 11 refers to the part between the top interface of the phreatic aquifer 11 and the point where the vertical distance from the bottom interface of the phreatic aquifer 11 is two-thirds of the thickness of the phreatic aquifer 11.

[0047] In this embodiment, in step S210 , the first borehole penetrates the phreatic aquifer 11 and is terminated after drilling 0.5 meters into the impermeable layer of the coal mining subsidence area 10 to obtain the water injection hole 31 .

[0048] Among them, when the thickness distribution difference of the soil layer 12 in the coal mining subsidence area 10 on the horizontal plane is small, multiple second boreholes are constructed at equal intervals on one side of the water injection hole 31 and in the direction away from the water injection hole 31. When the thickness distribution difference of the soil layer 12 in the coal mining subsidence area 10 on the horizontal plane is large, multiple second boreholes are constructed at equal intervals on both sides or multiple sides of the water injection hole 31 and in the direction away from the water injection hole 31, so that the irrigation influence radius determined according to the soil moisture content change value of the observation hole 32 can be applied to various positions of the coal mining subsidence area 10 in the horizontal direction.

[0049] In this embodiment, in step S220, 20 second boreholes are constructed at equal intervals on one side of the water injection hole 31 and in a direction away from the water injection hole 31. The second boreholes are drilled into the submerged aquifer 1 meter deep to obtain multiple observation holes 32, and the distance between two adjacent observation holes 32 is 1 meter.

[0050] In this embodiment, the preset pressure is 0.1 MPa, the preset time is 24 hours, and the preset depth is half the depth of the observation hole 32 .

[0051] In other embodiments, the preset depth is one-third to two-thirds of the depth of the observation hole 32. Using the preset depth within the above value range allows the water contained at the preset depth to be available for plant roots and facilitates the downward growth of plant roots.

[0052] like Figure 4 As shown, step S210 of constructing a first borehole in the coal mining subsidence area 10 includes:

[0053] S211, obtaining an average soil layer thickness in the coal mining subsidence area 10;

[0054] S212, obtaining the drilling position of the water injection hole 31, wherein the soil layer thickness at the drilling position of the water injection hole 31 is equal to the average soil layer thickness;

[0055] S213. Construct a first borehole at the drilling location of the water injection hole 31 to obtain the water injection hole 31. Since the soil layer thickness at the drilling location of the water injection hole 31 is equal to the average soil layer thickness of the coal mining subsidence area 10, the irrigation effect achieved by injecting water into the water injection hole 31 can represent the irrigation effect of the plant root irrigation method in the coal mining subsidence area, so that the irrigation impact radius can be applied to all locations in the coal mining subsidence area in the horizontal direction.

[0056] In this embodiment, step S230 of determining the irrigation influence radius according to the soil moisture change value includes:

[0057] S231. The maximum distance between the observation hole 32 and the water injection hole 31 at which the soil moisture content change exceeds a preset threshold is set as the irrigation influence radius. Using the irrigation influence radius determined in the above manner, the soil moisture content change can exceed the preset threshold while the horizontal distance from the water injection hole 31 is within the irrigation influence radius. This allows water to be injected into the water injection hole 31 at a preset pressure for a preset time. After the water injection is completed, the soil layer 12 is replenished within the irrigation influence radius at a horizontal distance from the water injection hole 31.

[0058] In this embodiment, the preset threshold corresponding to the preset height of the observation hole 32 is 150% of the soil moisture content before water injection from the water injection hole 31 .

[0059] like Figure 5 As shown, the step S100 of obtaining the depth parameter of the phreatic aquifer 11 in the coal mining subsidence area 10 and determining the irrigation depth according to the depth parameter of the phreatic aquifer 11 includes:

[0060] S110, evenly arranging a plurality of survey points in the coal mining subsidence area 10, and collecting statistics on the buried depth parameters of the phreatic aquifer 11 at the survey points;

[0061] S120, determining the depth of the upper portion of the unconfined aquifer 11 according to the burial depth parameter of the unconfined aquifer 11;

[0062] S130: Set the depth of the upper portion of the submerged aquifer 11 as the irrigation depth. By statistically analyzing the burial depth parameters of the submerged aquifer 11 at multiple survey points evenly distributed within the coal mining subsidence area 10, the horizontal distribution of the burial depth parameters of the submerged aquifer 11 in the coal mining subsidence area 10 can be obtained, thereby obtaining the horizontal distribution of the depth of the upper portion of the submerged aquifer 11 in the coal mining subsidence area 10, i.e., the horizontal distribution of the irrigation depth in the coal mining subsidence area 10. Compared to irrigation methods such as sprinkler irrigation or flooding, this method can determine the horizontal distribution of the irrigation depth in the coal mining subsidence area 10 based on the specific geological conditions of the coal mining subsidence area 10, thereby improving water resource utilization and irrigation efficiency during the irrigation process. Furthermore, by setting the depth of the upper portion of the submerged aquifer 11 as the irrigation depth, since the vertical distance from the soil layer 12 is the rock and soil consolidation at the irrigation depth, it is possible to avoid hole collapse during drilling or irrigation at this location, thereby improving the safety and reliability of the construction.

[0063] In this embodiment, the distance between two adjacent survey points is 10 meters, and the Luoyang shovel hole-making method is used to conduct a full coverage survey of the coal mining subsidence area, and the horizontal distribution of the burial depth parameters of the phreatic aquifer 11 in the coal mining subsidence area 10 is shown.

[0064] It should be noted that the burial depth parameter of the unconfined aquifer 11 includes the burial depth parameter of the top interface of the unconfined aquifer 11 and the burial depth parameter of the bottom interface of the unconfined aquifer 11. The burial depth parameter of the top interface of the unconfined aquifer 11 refers to the distance between the top interface of the unconfined aquifer and the top interface of the soil layer 12 in the vertical direction, and the burial depth parameter of the bottom interface of the unconfined aquifer 11 refers to the distance between the bottom interface of the unconfined aquifer 11 and the top interface of the soil layer 12 in the vertical direction; the upper part of the unconfined aquifer 11 refers to the part between the top interface of the unconfined aquifer 11 and the point where the vertical distance from the bottom interface of the unconfined aquifer 11 is two-thirds of the thickness of the unconfined aquifer 11 to the top interface of the unconfined aquifer 11.

[0065] In this embodiment, the thickness of the unconfined aquifer 11 is 10 meters, and the vertical distance of 8 meters from the bottom interface of the unconfined aquifer 11 is regarded as the upper section of the unconfined aquifer 11 .

[0066] like Figure 6 As shown, the step S300 of determining a drilling plan in the phreatic aquifer 11 according to the irrigation depth, the irrigation influence radius, and the topography of the coal mining subsidence area 10, and obtaining a directional drilling plan according to the drilling plan includes:

[0067] S310, dividing the coal mining subsidence area 10 into a plurality of strip areas 14 according to the irrigation influence radius and the maximum drilling capacity of the drilling rig, and obtaining a planar drilling plan according to the shape of the strip areas 14 and the irrigation influence radius;

[0068] S320, performing terrain elevation profile mapping of the coal mining subsidence area 10 along the extension direction of the strip area 14 to obtain terrain relief, and obtaining a profile drilling plan based on the terrain relief and irrigation depth;

[0069] S330, obtaining a drilling plan according to the plan drilling plan and the profile drilling plan;

[0070] S340. Obtain directional drilling according to the drilling plan. Divide the coal mining subsidence area 10 into multiple strip areas 14. The width of the strip area 14 is twice the irrigation influence radius, and the length of the strip area 14 is the length of the strip area 14. The drilling rig drills vertically downward from one end of the strip area 14 into the submerged aquifer 11, and then drills along the length direction of the strip area 14. Before the drilling rig reaches the maximum drilling capacity, the drill bit of the drilling rig can vertically penetrate the ground surface (i.e., the top interface of the soil layer 12). According to the shape of the strip area 14 and the irrigation influence radius, a plane drilling plan is obtained, that is, the symmetry axis of each strip area 14 extending along its length direction is the plane drilling plan, wherein the plane drilling plan refers to the projection of the drilling plan on the horizontal plane. According to the plane drilling plan, the drilling The hole plan then obtains a directional drill hole, and the horizontal distance between the directional drill holes in two adjacent strip areas 14 is twice the irrigation influence radius; the terrain elevation undulation profile mapping of the coal mining subsidence area 10 is carried out along the extension direction of the strip area 14 to obtain the terrain undulation, that is, the height distribution of the top interface of the soil layer 12 on the horizontal plane, and the profile drilling plan is obtained according to the terrain undulation and the irrigation depth, wherein the profile drilling plan refers to the trajectory of the directional drill hole on its vertical section, that is, the distance from the top interface of the soil layer 12 in the vertical direction, and the directional drill hole is obtained according to the profile drilling plan, so that the distance from the top interface of the soil layer 12 in the vertical direction is the irrigation depth.

[0071] Specifically, in step S320 of mapping the terrain elevation undulation profile of the coal mining subsidence area 10 along the extension direction of the strip area 14 to obtain the terrain undulation, a level, a total station, an RTK and other equipment can be used to map the terrain elevation undulation profile of the coal mining subsidence area 10 along the extension direction of the strip area 14 to obtain the terrain undulation.

[0072] In this embodiment, a level is used to perform contour measurement along the center line of the strip area 14 to obtain the topographic relief.

[0073] like Figure 8 As shown, in this embodiment, the width of the coal mining subsidence area 10 is 200 meters, the length of the coal mining subsidence area 10 is 1500 meters, the average vertical distance between the bottom interface of the phreatic aquifer 11 in the coal mining subsidence area 10 and the top interface of the soil layer 12 is 220 meters, and the maximum drilling capacity of the drilling rig when the drill bit diameter is 94 mm is 2000 m. The coal mining subsidence area 10 is divided into 10 strip areas 14 with a width of 20 m and a length of 1500 m.

[0074] like Figure 2 As shown, step S400 of inserting the irrigation pipe 20 into the directional drilled hole includes:

[0075] S410, before the drilling rig reaches its maximum drilling capacity, the drill bit of the drilling rig is driven out of the ground surface and the irrigation pipe 20 is connected to the drill bit;

[0076] S420: The drill rig performs a drill withdrawal operation, utilizing the drag effect of the drill bit as it withdraws to lay the irrigation pipe 20 within the directional borehole. After the drill bit of the drill rig penetrates the ground surface, the irrigation pipe 20 is connected to the drill bit, and the drag effect of the drill bit as it withdraws is utilized to lay the irrigation pipe 20 within the directional borehole. This simplifies the construction process of the directional drilling and irrigation pipe 20, improves irrigation preparation efficiency, and, because the irrigation pipe 20 is laid within the directional borehole, compared to laying the irrigation pipe 20 within the subsoil layer 12, avoids secondary damage to the soil layer 12 and the plant roots within the soil layer 12.

[0077] When the length of the irrigation branch pipe 21 is insufficient, a multi-section splicing process (such as hot melting, threading and other mature processes) can be used to connect the irrigation branch pipe 21.

[0078] In this embodiment, two adjacent sections of the irrigation branch pipe 21 are connected by a screw joint.

[0079] like Figure 2 As shown, the step S400 of inserting the irrigation pipe 20 into the directional drilled hole and irrigating through the irrigation pipe 20 further includes:

[0080] S430, the irrigation pipeline 20 includes multiple irrigation branches 21. Multiple moisture content observation devices 22 are arranged at intervals along the extension direction of each irrigation branch 21. The moisture content of the soil layer 12 in the coal mining subsidence area 10 is obtained through the multiple moisture content observation devices 22. Specifically, the moisture content observation device 22 is located between two adjacent irrigation branches 21, that is, the moisture content observation device 22 is located at the interface between two adjacent strip areas 14. At the same interface, the distance between two adjacent moisture content observation devices 22 is twice the irrigation influence radius. Using the above arrangement of the moisture content observation devices 22, the moisture content observation devices 22 can be used to detect whether the multiple irrigation branches 21 have completed irrigation.

[0081] A plurality of water outlet points are arranged at intervals along the extension direction of the irrigation branch pipe 21 , and a plurality of water outlets are evenly arranged at each water outlet point along the circumference of the irrigation branch pipe 21 .

[0082] Specifically, the distance between two adjacent water outlets on the same irrigation branch pipe 21 is between 100 mm and 300 mm. Each water outlet is evenly distributed along the circumference of the irrigation branch pipe 21, with at least five outlets having a diameter between 1 mm and 3 mm. Using outlets within this diameter range prevents clogging caused by calcification of the water, and prevents sediment from entering the irrigation branch pipe 21 through the outlets, thereby preventing the irrigation effect of the irrigation branch pipe 21.

[0083] In other embodiments, the distance between two adjacent water outlet points on the same irrigation branch pipe 21 can be 100 mm, 150 mm, 200 mm, 250 mm, 300 mm, and any value between 100 mm and 300 mm, and the aperture of the water outlet can be 1 mm, 1.5 mm, 2 mm, 2.5 mm, 3 mm, and any value between 1 mm and 3 mm.

[0084] In this embodiment, the distance between two adjacent water outlet points on the same irrigation branch pipe 21 is 100 mm, and 5 water outlets are evenly arranged at each water outlet point along the circumference of the irrigation branch pipe 21, and the aperture of the water outlet is 2 mm.

[0085] In this embodiment, the step S440 of detecting the water content within the range of the irrigation influence radius from the irrigation pipeline 20 and controlling the working state of the irrigation pipeline 20 according to the water content includes:

[0086] S441. When the water content within the irrigation influence radius from the irrigation branch pipe 21 reaches the irrigation requirement, stop the water supply from the irrigation branch pipe 21. When the water content within the irrigation influence radius from the irrigation branch pipe 21 reaches the irrigation requirement, that is, the irrigation branch pipe 21 has completed irrigation of the strip area 14 in which it is located, stop the water supply from the irrigation branch pipe 21 to avoid overirrigation.

[0087] Among them, if the moisture content detected by the moisture content observation device 22 cannot meet the irrigation requirements, it means that there are cracks in the submerged aquifer 11 corresponding to the moisture content observation device 22. During irrigation operations, it is necessary to avoid this place to avoid ineffective irrigation and waste of water resources.

[0088] In this embodiment, the diameter of the irrigation branch pipe 21 is set to be less than or equal to 1 / 2 the diameter of the directional drilled hole. This diameter creates a gap between the outer wall of the irrigation branch pipe 21 and the wall of the directional drilled hole in the radial direction. This prevents sand from entering the irrigation branch pipe 21 during water injection and reduces drag on the irrigation branch pipe 21 when it is inserted into the directional drilled hole.

[0089] In this embodiment, the diameter of the drill bit of the drill is 94 mm, and the diameter of the irrigation branch pipe 21 is 50 mm.

[0090] like Figure 8As shown, the irrigation pipeline 20 also includes a water supply pipe 23. The first ends of the multiple irrigation branch pipes 21 are connected to the water supply pipe 23. The first ends of the multiple irrigation branch pipes 21 are each provided with a first valve body 211, and the second ends of the multiple irrigation branch pipes 21 are each provided with a second valve body 212. The water supply of the irrigation branch pipes 21 is controlled by the first valve body 211. After sand enters the irrigation branch pipes 21, the sand is cleared by opening the second valve body 212. When irrigation is performed using the irrigation branch pipe 21, the first valve body 211 is opened and the second valve body 212 is closed, so that the water in the irrigation branch pipe 21 enters the submerged aquifer 11 through the small holes on the side wall of the irrigation branch pipe 21. After irrigation with the irrigation branch pipe 21 is completed, the first valve body 211 is closed and the second valve body 212 is closed. When excessive sediment in the irrigation branch pipe 21 affects the irrigation effect of the irrigation branch pipe 21, the first valve body 211 is opened and the second valve body 212 is opened, so that the sediment in the irrigation branch pipe 21 is discharged from the first end of the irrigation branch pipe 21 to the second end of the irrigation branch pipe 21 along with the water in the irrigation branch pipe 21, thereby achieving a sediment clearing effect.

[0091] Specifically, the first valve body 211 and the second valve body 212 are both control ball valves.

[0092] like Figure 8 As shown, the water inlet of the water supply pipe 23 is connected to the water supply station 40, which provides water for the irrigation pipeline 20. The water supply station 40 pumps water directly to the submerged aquifer at a certain pump pressure, so as to utilize the recovered submerged aquifer to supply water to the soil layer above it, using deep root water supply to improve irrigation efficiency.

[0093] Applying the method provided in this embodiment has the following beneficial effects:

[0094] (1) A drilling scheme within the phreatic aquifer 11 of the coal mining subsidence area 10 is determined based on the irrigation depth, irrigation influence radius, and topographic relief of the coal mining subsidence area 10, so that irrigation can be carried out according to the specific conditions of the coal mining subsidence area 10, thereby improving the utilization rate of water resources during irrigation and improving irrigation efficiency;

[0095] (2) The water level of the submerged aquifer 11 is restored by running an irrigation pipe 20 through a directional borehole, so that the submerged aquifer 11 with restored water level can be used to supply water to the soil layer 12 above it. Deep root system water supply is adopted. Since plant roots have a tendency to move towards water, the roots of plants in the coal mining subsidence area 10 grow downward, thus preventing plants with shallow roots from easily falling over in heavy rains and dying from lack of water in droughts, thereby improving the stress resistance and ecological stability of vegetation in the coal mining subsidence area 10.

[0096] (3) A directional borehole is obtained according to the drilling plan. Since the directional borehole is located in the submerged aquifer 11, compared with drilling in the soil layer 12, secondary damage to the soil layer 12 and the plant roots in the soil layer 12 can be avoided;

[0097] (4) Irrigation through the irrigation pipe 20 inserted into the directional drill hole can reduce water volatilization during the irrigation process and avoid water resource waste. In addition, since the irrigation pipe 20 is buried underground, the irrigation pipe 20 is protected from wind and rain, and the aging speed of the irrigation pipe 20 is slowed down.

[0098] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, they indicate the presence of features, steps, operations, devices, components and / or combinations thereof.

[0099] Unless otherwise specifically stated, the relative arrangement of the parts and steps, numerical expressions and numerical values ​​set forth in these embodiments do not limit the scope of the present invention. At the same time, it should be understood that, for ease of description, the sizes of the various parts shown in the accompanying drawings are not drawn according to actual proportional relationships. The technology, methods and equipment known to those of ordinary skill in the relevant art may not be discussed in detail, but in appropriate cases, the technology, methods and equipment should be considered as a part of the specification. In all examples shown and discussed here, any specific value should be interpreted as being merely exemplary, rather than as a limitation. Therefore, other examples of the exemplary embodiments can have different values. It should be noted that similar numbers and letters represent similar items in the following drawings, and therefore, once an item is defined in an accompanying drawing, it does not need to be further discussed in subsequent drawings.

[0100] In the description of the present invention, it should be understood that the directions or positional relationships indicated by directional words such as "front, back, up, down, left, right", "horizontal, vertical, perpendicular, horizontal" and "top, bottom" are usually based on the directions or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description. Unless otherwise specified, these directional words do not indicate or imply that the device or element referred to must have a specific direction or be constructed and operated in a specific direction. Therefore, they cannot be understood as limiting the scope of protection of the present invention; the directional words "inside and outside" refer to the inside and outside relative to the outline of each component itself.

[0101] For ease of description, spatially relative terms such as "above", "above", "on the upper surface of", "above", etc. may be used herein to describe the spatial positional relationship of a device or feature to other devices or features as shown in the figures. It should be understood that spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation described in the figures. For example, if the device in the drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "below other devices or structures". Thus, the exemplary term "above" can include both "above" and "below". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatially relative descriptions used here are interpreted accordingly.

[0102] In addition, it should be noted that the use of terms such as "first" and "second" to limit components is only for the convenience of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore cannot be understood as limiting the scope of protection of the present invention.

[0103] The foregoing description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention are intended to be within the scope of protection of the present invention.

Claims

1. A method for irrigating plant roots in coal mining subsidence areas, characterized in that: The plant root irrigation method in the coal mining subsidence area comprises: Obtaining a burial depth parameter of a phreatic aquifer (11) in a coal mining subsidence area (10), and determining an irrigation depth according to the burial depth parameter of the phreatic aquifer (11); Determine the irrigation impact radius; Determining a drilling plan in the phreatic aquifer (11) according to the irrigation depth, the irrigation influence radius, and the topographic relief of the coal mining subsidence area (10), and obtaining a directional drilling according to the drilling plan; Inserting an irrigation pipe (20) into the directional drilled hole and irrigating through the irrigation pipe (20); The step of irrigating through the irrigation pipeline (20) comprises: detecting the moisture content within a range of the irrigation influence radius at a distance from the irrigation pipeline (20), and controlling the working state of the irrigation pipeline (20) according to the moisture content.

2. The method for irrigating plant roots in coal mining subsidence areas according to claim 1, characterized in that: The steps to determine the irrigation influence radius include: constructing a first borehole in the coal mining subsidence area (10), wherein the first borehole penetrates the phreatic aquifer (11) and terminates after drilling to the upper part of the aquiclude (13) of the coal mining subsidence area (10), thereby obtaining a water injection hole (31); constructing a plurality of second boreholes at equal intervals on the same side of the water injection hole (31) and in a direction away from the water injection hole (31), wherein the second boreholes are drilled to the upper part of the submerged aquifer (11) to obtain a plurality of observation holes (32); Water is injected into the water injection hole (31) at a preset pressure for a preset time. After the water injection is completed, a soil moisture content change value at a preset depth of the observation hole (32) is obtained, and the irrigation influence radius is determined based on the soil moisture content change value.

3. The method for irrigating plant roots in coal mining subsidence areas according to claim 2, characterized in that: The steps of constructing a first borehole in the coal mining subsidence area (10) include: Obtaining an average soil layer thickness in the coal mining subsidence area (10); Obtaining a drilling position of a water injection hole (31), wherein the soil layer thickness at the drilling position of the water injection hole (31) is equal to the average soil layer thickness; The first borehole is constructed at the drilling position of the water injection hole (31) to obtain the water injection hole (31).

4. The method for irrigating plant roots in coal mining subsidence areas according to claim 2, characterized in that: The step of determining the irrigation influence radius according to the soil moisture content change value includes: The maximum distance between the observation hole (32) and the water injection hole (31) at which the soil moisture content change value exceeds a preset threshold is set as the irrigation influence radius.

5. The method for irrigating plant roots in coal mining subsidence areas according to any one of claims 1 to 4, characterized in that: The steps of obtaining a burial depth parameter of a phreatic aquifer (11) in a coal mining subsidence area (10), and determining an irrigation depth according to the burial depth parameter of the phreatic aquifer (11) include: Evenly arranging a plurality of survey points in the coal mining subsidence area (10), and statistically analyzing the burial depth parameters of the phreatic aquifer (11) at the survey points; Determining the depth of the upper portion of the submerged aquifer (11) based on the buried depth parameter of the submerged aquifer (11); The depth of the upper portion of the submerged aquifer (11) is set as the irrigation depth.

6. The method for irrigating plant roots in coal mining subsidence areas according to any one of claims 1 to 4, characterized in that: The steps of determining a drilling scheme in the phreatic aquifer (11) according to the irrigation depth, the irrigation influence radius and the topographic relief of the coal mining subsidence area (10), and obtaining a directional drilling according to the drilling scheme include: The coal mining subsidence area (10) is divided into a plurality of strip areas (14) according to the irrigation influence radius and the maximum drilling capacity of the drilling rig, and a plane drilling plan is obtained according to the shape of the strip areas (14) and the irrigation influence radius; Performing terrain elevation profile mapping of the coal mining subsidence area (10) along the extension direction of the strip area (14) to obtain the terrain undulation, and obtaining a profile drilling plan based on the terrain undulation and the irrigation depth; Obtaining the drilling plan according to the plane drilling plan and the profile drilling plan; The directional drilling is obtained according to the drilling plan.

7. The method for irrigating plant roots in coal mining subsidence areas according to any one of claims 1 to 4, characterized in that: The step of inserting the irrigation pipe (20) into the directional drilled hole comprises: Before the drilling rig reaches its maximum drilling capacity, the drill head of the drilling rig is pulled out of the ground and the irrigation pipe (20) is connected to the drill head; The drilling rig performs a drill-back operation, and utilizes the dragging effect of the drill bit when the drill is backed out to lay the irrigation pipeline (20) in the directional drill hole.

8. The method for irrigating plant roots in coal mining subsidence areas according to any one of claims 1 to 4, characterized in that: The steps of inserting an irrigation pipe (20) into the directional borehole and irrigating through the irrigation pipe (20) include: the irrigation pipe (20) includes a plurality of irrigation branches (21), a plurality of moisture content observation devices (22) are arranged at intervals along the extension direction of each of the irrigation branches (21), and the moisture content of the soil layer (12) of the coal mining subsidence area (10) is obtained through the plurality of moisture content observation devices (22); The steps of detecting the water content within the range of the irrigation influence radius from the irrigation pipeline (20) and controlling the working state of the irrigation pipeline (20) according to the water content include: when the water content within the range of the irrigation influence radius from the irrigation branch pipe (21) reaches the irrigation requirement, stopping the water supply of the irrigation branch pipe (21).

9. The method for irrigating plant roots in coal mining subsidence areas according to claim 8, characterized in that: Setting the diameter of the irrigation branch pipe (21) to be less than or equal to 1 / 2 of the diameter of the directional drilled hole; and / or, The irrigation pipeline (20) further comprises a water supply pipe (23), the first ends of the plurality of irrigation branch pipes (21) are all connected to the water supply pipe (23), the first ends of the plurality of irrigation branch pipes (21) are all provided with a first valve body (211), and the second ends of the plurality of irrigation branch pipes (21) are all provided with a second valve body (212), the water supply of the irrigation branch pipes (21) is controlled by the first valve body (211), and after sand enters the irrigation branch pipes (21), the sand is cleared by opening the second valve body (212).

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