A method for filling high-level interlayer cavity with wind-blown sand

Abstract

The application discloses an implementation method for filling high-position separation cavity with wind deposited sand, which comprises the following steps: selecting the position of surface opening, drilling and casing the wind deposited sand stratum based on the position of the surface opening; drilling the bedrock stratum based on the surface opening, and making the final hole position a certain preset distance from the top interface of the water flowing fractured zone; pushing the working face through the borehole, pulling the casing up after the surface opening appears air suction phenomenon, and making the wind deposited sand enter the inside of the opening; continuing to push the working face, pulling the casing up after the air suction phenomenon at the surface opening intensifies, and adding the binder through the surface opening; stopping the binder putting after the air suction phenomenon stops, slowly pressing the casing back to the original position; and repeating the above process until the working face mining is completed. The application overcomes the difficulties of grouting material transportation and high pumping process requirements, greatly reduces the difficulty and cost of separation filling, and realizes local material utilization without pumping equipment.

Description

Technical Field

[0001] This invention belongs to the field of green mining technology in coal mines, specifically relating to a method for filling high-level delamination cavities with aeolian sand. Background Technology

[0002] In recent years, my country's coal production strategy has gradually shifted westward. The Jurassic coal seams in the Ordos Basin, with their high-quality coal and vast reserves, have become an important coal production base in my country. However, research shows that large-scale, high-intensity coal seam excavation can cause a redistribution of the original stress field within the overlying rock and soil, leading to bending deformation, delamination, fracture movement, and even collapse of the overlying rock. This, in turn, causes uneven surface subsidence, damages shallow ecological water bodies, and impacts the human living environment. Grouting using the delamination cavities is currently the main method for reducing surface subsidence.

[0003] However, current grouting materials for delamination are mostly fly ash and high-moisture materials, requiring high-pressure hydraulic pressure to transport them into the delamination cavity through pump pipelines and injection holes. This results in a large grouting workload, expensive materials, and complex construction techniques. Furthermore, the fineness of the grout and the limitations of traditional high-pressure grouting processes can lead to grout leakage or even water inrush accidents underground, resulting in wasted work and safety hazards. Therefore, traditional delamination grouting methods are not suitable for grouting and settling reduction work in the context of high-intensity mining of Jurassic coal seams in the Ordos Basin of my country. Summary of the Invention

[0004] This invention proposes a method for filling high-level delamination cavities with aeolian sand. By using surface drilling, aeolian sand strata are used as filling material to fill high-level delamination cavities located above water-conducting fracture zones.

[0005] To achieve the above objectives, the present invention provides the following solution:

[0006] A method for filling high-level delamination cavities with aeolian sand includes:

[0007] S1. Select the location of the surface opening, and drill and run casing in the aeolian sand strata based on the location of the surface opening;

[0008] S2. Drilling is carried out on the bedrock strata based on the surface opening, so that the final hole position is a certain preset distance from the top interface of the water-conducting fracture zone.

[0009] S3. After the working face pushes past the borehole and the surface opening shows a suction phenomenon, the casing is pulled up to allow the wind-accumulated sand to enter the opening.

[0010] S4. As the working face continues to advance, and the air suction at the surface opening intensifies, the sleeve is pulled up and adhesive is added through the surface opening.

[0011] S5. After the suction phenomenon stops, stop the application of the adhesive and slowly press the sleeve back to its original position;

[0012] S6. Repeat S1-S5 above until the working face mining is completed.

[0013] Preferably, the method for selecting the location of the surface opening in S1 includes:

[0014] The aforementioned surface drilling was carried out in an unmined area 50-100m away from the working face.

[0015] Preferably, the sleeve in S1 is a double-layer sleeve;

[0016] The double-layered sleeve has a solid inner sleeve and a perforated outer sleeve.

[0017] Preferably, the diameter of the solid sleeve is not less than 130 mm.

[0018] Preferably, the opening size of the perforated tube is 2mm × 15mm, and the total opening area accounts for no less than 10% of the total area of ​​the perforated tube.

[0019] Preferably, the preset distance mentioned in S2 is not less than 50m.

[0020] Preferably, the final hole diameter in S2 is not less than 91 mm.

[0021] Preferably, the binder in S4 comprises: 30-35% fly ash, 25-30% coal gangue with a particle size of less than 5mm, 25-30% modified gypsum, 13-15% silicate cement clinker, and 0.5-1.5% early strength agent.

[0022] The beneficial effects of this invention are as follows:

[0023] This invention provides a method for filling high-level delamination cavities with aeolian sand. It is the first method to propose using ground drilling to utilize aeolian sand layers, widely distributed in the arid and semi-arid regions of western my country, as filling material for high-level delamination filling. This invention eliminates the need for pumping equipment and utilizes locally sourced materials, overcoming the difficulties of transporting grouting materials and the high requirements of pumping processes. It significantly reduces the difficulty and cost of delamination filling, and mining areas can design delamination filling implementation schemes based on this invention. Attached Figure Description

[0024] To more clearly illustrate the technical solution of the present invention, the drawings used in the embodiments are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0025] Figure 1This is a schematic diagram of the implementation method of filling high-level delamination cavities with aeolian sand according to the present invention;

[0026] Figure 2 This is a schematic diagram of the planar arrangement of ground boreholes above the mining face of the present invention;

[0027] Figure 3 This is a schematic diagram of the borehole cross-section for delamination filling using aeolian sand according to the present invention;

[0028] Figure 4 This is a front view of the flower tube used in this invention.

[0029] Explanation of reference numerals in the attached figures:

[0030] 1-Perforated tube; 2-Solid sleeve; 3-Bare hole; 4-Delamination filler. Detailed Implementation

[0031] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0032] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0033] Example 1

[0034] This example uses the Northwest Mining Field as an example. The surface of the Northwest Mining Field is mostly covered by aeolian sand, representing a typical aeolian sandbar landform. According to drilling data and geological mapping, the average thickness of the aeolian sand in the area reaches 59.18m, forming an unconformable contact with the underlying Cretaceous bedrock. A certain working face in this mine mainly mines the 2-2 coal seam, which is nearly horizontal, with an average thickness of 6.4m and a burial depth of approximately 730.4m. The working face has a strike length of 2500m and a dip width of 290m.

[0035] like Figure 1 The diagram shown is a schematic flow chart of an implementation method for filling high-level delamination cavities with aeolian sand according to the present invention. The method involves using surface drilling to fill high-level delamination cavities with aeolian sand strata as the filling material. The method includes the following steps:

[0036] S1. Select the location of the surface opening, and drill and run casing in the aeolian sand strata based on the location of the surface opening.

[0037] Specifically: such as Figure 2As shown, surface drilling is carried out in an unmined area 50-100m from the working face. In this embodiment, surface drilling is carried out in an unmined area 100m from the working face. Drilling is conducted within the aeolian sand layer, and a double-layer casing is installed. The inner layer of the double-layer casing is a solid casing 2, and the outer layer is a perforated casing 1. The diameter of the solid casing 2 is not less than 130mm; in this embodiment, the diameter of the solid casing 2 is 130mm. Figure 4 As shown, the opening size of the perforated tube 1 is 2mm × 15mm. The total area of ​​the opening accounts for no less than 10% of the total area of ​​the perforated tube 1, and the opening positions are arranged in a staggered quincunx pattern.

[0038] S2. Drilling of bedrock strata based on surface openings, so that the final hole position is a certain preset distance from the top interface of the water-conducting fracture zone;

[0039] Specifically: Drill downwards from the bottom of the aeolian sand layer until the bottom interface of the Cretaceous layer, so that the final hole position is at least 50m away from the top interface of the water-conducting fracture zone. In this embodiment, the final hole position is set at about 150m away from the top interface of the water-conducting fracture zone. This section of the borehole does not expose mudstone. This section of the borehole is a bare hole 3, and the final hole diameter is not less than 91mm.

[0040] S3. After the working face pushes past the borehole and air suction occurs at the surface opening, pull the casing up to allow the wind-accumulated sand to enter the opening.

[0041] Specifically: such as Figure 3 As shown, when the working face pushes past the borehole, the surface borehole begins to suck in air. At this time, the drilling rig slowly pulls the solid casing 2 inside the aeolian sand up by 0.2 to 0.5 m, so that the aeolian sand slowly enters the borehole through the perforated pipe 1, thereby filling the delamination cavity and forming the delamination filling body 4.

[0042] S4. As the working face continues to advance, the air suction at the surface opening intensifies. Pull the casing upwards and add adhesive through the surface opening.

[0043] Specifically: As the working face continues to advance, the air suction phenomenon at the surface borehole intensifies. When obvious air suction occurs, the solid casing 2 inside the aeolian sand is slowly pulled up by the drilling rig again by 0.2 to 0.5 m. If the air suction phenomenon at the surface borehole continues to be unable to be relieved, the number of times the solid casing 2 is pulled up can be increased by 2 to 3 times, or adhesive can be added through the borehole opening.

[0044] The binder composition includes: 30-35% fly ash, 25-30% coal gangue with a particle size of less than 5mm, 25-30% modified gypsum, 13-15% silicate cement clinker, and 0.5-1.5% accelerator. In this embodiment, the composition is 35% fly ash, 25% coal gangue with a particle size of less than 5mm, 25% modified gypsum, 14% silicate cement clinker, and 1% accelerator.

[0045] S5. After the suction stops, stop adding adhesive and slowly press the sleeve back to its original position.

[0046] Specifically: As the working face continues to advance, the air suction phenomenon at the surface borehole gradually weakens. When the air suction phenomenon completely disappears, the application of adhesive is stopped, and the solid casing 2 inside the aeolian sand is slowly pressed back to its original position using the drilling rig, and the construction of borehole 2 is carried out.

[0047] S6. Repeat S1-S5 above until the working face mining is completed.

[0048] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made to the technical solutions of the present invention by those skilled in the art without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A method for filling high-level delamination cavities with aeolian sand, characterized in that, include: S1. Select the location of the surface opening, and drill and run casing in the aeolian sand strata based on the location of the surface opening. The sleeve described in S1 is a double-layer sleeve; The double-layered sleeve has a solid inner sleeve and a perforated outer sleeve. The diameter of the solid sleeve is not less than 130mm; The opening size of the perforated tube is 2mm×15mm, and the total opening area accounts for no less than 10% of the total area of ​​the perforated tube. S2. Drilling of bedrock strata based on the surface opening, so that the final hole position is a certain preset distance from the top interface of the water-conducting fracture zone; S3. After the working face pushes past the borehole and the surface opening shows a suction phenomenon, the drilling rig slowly pulls up the solid casing inside the aeolian sand, so that the aeolian sand slowly enters the borehole through the perforated pipe. S4. As the working face continues to advance, the air suction phenomenon at the surface opening intensifies. The solid casing in the aeolian sand is slowly pulled up again using the drilling rig, and adhesive is added through the surface opening. S5. After the suction phenomenon stops, stop the application of the adhesive and slowly press the sleeve back to its original position; S6. Repeat S1-S5 above until the working face mining is completed.

2. The method for filling high-level delamination cavities with aeolian sand according to claim 1, characterized in that, S1 The method for selecting the location of the surface opening includes: The aforementioned surface drilling was carried out in an unmined area 50-100m away from the working face.

3. The method for filling high-level delamination cavities with aeolian sand according to claim 1, characterized in that, The preset distance mentioned in S2 is not less than 50m.

4. The method for filling high-level delamination cavities with aeolian sand according to claim 1, characterized in that, The final hole diameter of S2 is not less than 91mm.

5. The method for filling high-level delamination cavities with aeolian sand according to claim 1, characterized in that, The binder described in S4 includes: 30-35% fly ash, 25-30% coal gangue with a particle size of less than 5mm, 25-30% modified gypsum, 13-15% silicate cement clinker, and 0.5-1.5% early strength agent.

Images