A sealing structure of a waste coal mine shaft mouth and a construction method

Abstract

The application discloses a kind of abandoned coal mine well mouth plugging structure and construction method, belong to abandoned mine plugging technical field, comprising: annular concrete wall, reinforced cement column, impermeable cement layer, well mouth brick layer, gravel layer and water permeation pipe;Multiple annular concrete walls are distributed in the abandoned coal mine well mouth with interval, reinforced cement column is sequentially connected multiple annular concrete walls, multiple impermeable cement layers are arranged on the ring well mouth wall, are distributed between multiple annular concrete walls, well mouth brick layer is arranged in well mouth, gravel layer is filled in the space surrounded by annular concrete wall, impermeable cement layer and well mouth brick layer, water permeation pipe passes through well mouth brick layer and annular concrete wall and extends into abandoned coal mine well.The application can be plugged to the abandoned coal mine well mouth, the strength of plugging structure is high, saves cost, avoids that plugging structure is soaked by mine gushing water, also avoids forming new acid waste water, protects environment.

Description

Technical Field

[0001] This invention belongs to the field of abandoned mine well sealing technology, and particularly relates to a sealing structure and construction method for abandoned coal mine wellheads. Background Technology

[0002] Coal mining is the primary way to obtain coal resources, but mines can become depleted or unsuitable for continued operation. Once a mine is decommissioned and production and drainage cease, a large amount of mine water will flow into the mine. Because the ore body contains various metals and sulfide minerals, the mine walls and waste rock inside undergo oxidation reactions under the combined influence of air, water, and microorganisms, generating highly acidic substances. This process dissolves various heavy metal ions from the ore, producing acidic wastewater containing pollutants such as copper, iron, lead, zinc, cadmium, and arsenic. This wastewater not only flows to the surface, causing heavy metal pollution in the mining area and receiving water bodies, but also causes cross-contamination of groundwater through geological fissures and faults. Backfilling abandoned mines would require a massive amount of material, resulting in extremely high costs, extensive underground material transportation, a large workload, and a long construction period. Sealing the mine shafts is currently the primary method used. Sealing the wellhead of abandoned mines can prevent the metals and sulfides inside the mine from coming into contact with air and being oxidized to form acidic wastewater. However, the current wellhead sealing structure still requires filling or pouring a long section of cement at the wellhead, which increases costs. The strength of the poured cement structure will also decrease if it is soaked in seepage water at the wellhead for a long time. Summary of the Invention

[0003] In view of this, the present invention provides a sealing structure and construction method for abandoned coal mine shafts, which addresses the shortcomings of the prior art and solves the problems mentioned in the background art.

[0004] To achieve the above objectives, the present invention adopts the following technical solution:

[0005] A sealing structure for an abandoned coal mine shaft includes: annular concrete walls, reinforced concrete columns, an impermeable cement layer, a shaft shaft brickwork layer, a crushed stone layer, and a permeable pipe; multiple annular concrete walls are spaced apart in the abandoned coal mine shaft; the reinforced concrete columns are connected in series with multiple annular concrete walls; multiple sections of the impermeable cement layer are disposed on the shaft shaft wall and distributed between the multiple annular concrete walls; the shaft shaft brickwork layer is disposed at the shaft shaft; the crushed stone layer fills the space enclosed by the annular concrete walls, the impermeable cement layer, and the shaft shaft brickwork layer; and the permeable pipe extends through the shaft shaft brickwork layer and the annular concrete walls into the abandoned coal mine shaft.

[0006] Furthermore, the cross-section of the annular concrete wall is funnel-shaped, facing outwards and extending into the wellhead wall.

[0007] Furthermore, the permeable pipe is located near the top of the wellhead wall.

[0008] Furthermore, a one-way valve is provided at the outlet of the permeable pipe.

[0009] A construction method for a sealing structure at the entrance of an abandoned coal mine includes the following steps:

[0010] S1. Identify the construction section at the abandoned coal mine shaft and clean up the construction section;

[0011] S2. Excavate multiple annular concrete wall trenches at certain intervals in the coal mine shaft construction section;

[0012] S3. First, pour the innermost ring-shaped concrete wall, then pour the wellhead wall in a ring shape next to the ring-shaped concrete wall to form a seepage-proof cement layer, and finally fill the crushed stone layer.

[0013] S4. Repeat step S3 to create multiple sets of ring-shaped concrete walls, impermeable cement layers, and crushed stone layers;

[0014] S5. Construct a brickwork layer at the wellhead and seal the edges around the wellhead with cement.

[0015] Furthermore, in step S1, after the construction section is cleaned up, drainage ditches are excavated on both sides of the roadway to discharge the acidic wastewater.

[0016] Furthermore, in step S3, before pouring the impermeable cement layer, high-pressure cement is poured into the leaking area of ​​the wellhead wall.

[0017] Furthermore, after high-pressure cement is poured into the leaking area, the wellhead wall is roughened.

[0018] Furthermore, in step S3, after the impermeable cement layer and before the crushed stone layer is filled, a reinforced concrete column is cast between adjacent annular concrete walls using a steel cage.

[0019] The beneficial effects of this invention are as follows:

[0020] The annular concrete wall, reinforced cement column, and impermeable cement layer of this invention serve as the structural framework, with a crushed stone layer filling the middle. This reduces the amount of cement used for sealing during construction, saving costs. At the same time, the crushed stone layer improves the support for the sealing structure, and the impermeable cement layer prevents water from the surrounding area of ​​the mine from seeping into the sealing structure and reducing the strength of the internal cement structure. The annular concrete wall, with a trumpet-shaped cross-section extending outward into the wellhead wall, prevents the sealing structure from being squeezed by the surrounding area of ​​the mine or from moving outward under other circumstances. The permeable pipe is located near the top of the wellhead wall, which can discharge excess water from the mine inside the sealing structure to the outside. The one-way valve at the end of the permeable pipe can prevent outside air from entering the mine and causing metal oxides and sulfides to form acidic wastewater. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0022] Figure 1 This is a schematic diagram of a sealing structure for an abandoned coal mine shaft.

[0023] In the figure:

[0024] 10-Wellhead wall, 20-Annular concrete wall, 21-Annular concrete wall trench, 30-Reinforced cement column, 40-Imperible cement layer, 50-Wellhead brickwork layer, 60-Gravel layer, 70-Permeable pipe, 80-One-way valve. Detailed Implementation

[0025] 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. Example 1

[0026] See attached document Figure 1 As shown, the present invention provides a sealing structure for an abandoned coal mine shaft, comprising: annular concrete walls 20, reinforced cement columns 30, impermeable cement layers 40, shaft opening brick masonry layers 50, crushed stone layers 60, and permeable pipes 70; multiple annular concrete walls 20 are spaced apart in the abandoned coal mine shaft, reinforced cement columns 30 are connected in series with multiple annular concrete walls 20, multiple sections of impermeable cement layers 40 are set on the annular shaft opening wall 10 and distributed between the multiple annular concrete walls 20, shaft opening brick masonry layers 50 are set at the shaft opening, crushed stone layers 60 are filled in the space enclosed by the annular concrete walls 20, the impermeable cement layers 40, and the shaft opening brick masonry layers 50, and permeable pipes 70 extend into the abandoned coal mine shaft through the shaft opening brick masonry layers 50 and the annular concrete walls 20.

[0027] In one preferred embodiment, the cross-section of the annular concrete wall 20 is funnel-shaped and extends outward into the wellhead wall 10 to prevent the surrounding area of ​​the mine from squeezing the sealing structure or other situations that cause the sealing structure to move outward.

[0028] In one preferred embodiment, the permeable pipe 70 is positioned close to the top of the wellhead wall 10. When the water inflow in the abandoned well increases and the water level in the well is high, it prevents the pressure inside the well from becoming too high and putting pressure on the sealing structure. The permeable pipe 70, which is positioned high, can discharge the excessive water inflow in the mine to the outside, thereby reducing the internal pressure.

[0029] In a preferred embodiment, the outlet of the permeable pipe 70 is equipped with a one-way valve 80. This one-way valve 80 allows water from the mine to drain outwards, while preventing outside air from entering the mine and causing metal oxides or sulfides, thus preventing the generation of acidic waste liquid. The combination of the permeable pipe 70 and the one-way valve 80 can also facilitate the discharge of mine gas. A gas monitoring and collection device can be installed at the outlet of the one-way valve 80. Example 2

[0030] A construction method for a sealing structure at the entrance of an abandoned coal mine includes the following steps:

[0031] S1. Determine the construction section at the entrance of the abandoned coal mine and clean up the construction section. After the construction section is cleaned up, dig drainage ditches on both sides of the roadway to discharge the acidic wastewater.

[0032] S2. Excavate multiple annular concrete wall trenches 21 at certain intervals in the coal mine shaft construction section;

[0033] S3. First, the innermost annular concrete wall 20 is poured and formed. Then, high-pressure cement is poured into the leaking area of ​​the wellhead wall 10. The cement is injected into the cracks in the wellhead wall 10 to block the seepage. The high-pressure cement can also form an integral structure with the wellhead wall 10, which improves the strength of the sealing structure. Then, the wellhead wall 10 is roughened. Next, the wellhead wall 10 is poured in a ring next to the annular concrete wall 20 to form a seepage-proof cement layer 40. The roughening treatment can make the seepage-proof cement layer 40 bond more firmly with the wellhead wall 10. Finally, a crushed stone layer 60 is filled. The crushed stone is sourced locally around the mine. After the seepage-proof cement layer 40 and before the crushed stone layer 60 is filled, a reinforced concrete column 30 is poured between the adjacent annular concrete walls 20 using a steel cage. This makes the overall integrity of the sealing structure stronger and improves the structural strength.

[0034] S4. Repeat step S3 to construct multiple sets of ring-shaped concrete walls 20, impermeable cement layers 40, and crushed stone layers 60.

[0035] S5. Construct a 50mm brick masonry layer at the wellhead and seal the edges around the wellhead with cement.

[0036] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the apparatus disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the description is relatively simple; relevant parts can be referred to the method section.

[0037] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A sealing structure for an abandoned coal mine shaft, characterized in that, include: Ring-shaped concrete wall, reinforced cement column, impermeable cement layer, wellhead brickwork layer, crushed stone layer and permeable pipe; Multiple annular concrete walls are spaced apart in the abandoned coal mine shaft. The reinforced concrete columns are connected in series with the multiple annular concrete walls. Multiple sections of the impermeable cement layer are set on the shaft wall and distributed between the multiple annular concrete walls. The shaft shaft brickwork layer is set at the shaft shaft. The crushed stone layer fills the space enclosed by the annular concrete walls, the impermeable cement layer and the shaft shaft brickwork layer. The permeable pipe passes through the shaft shaft brickwork layer and the annular concrete walls and extends into the abandoned coal mine shaft. The permeable pipe is located near the top of the wellhead wall; The outlet of the permeable pipe is equipped with a one-way valve.

2. The sealing structure for an abandoned coal mine shaft according to claim 1, characterized in that, The cross-section of the annular concrete wall is trumpet-shaped, facing outwards and extending into the wellhead wall.

3. A construction method for a sealing structure at the entrance of an abandoned coal mine, used to achieve the sealing structure at the entrance of an abandoned coal mine as described in claim 2, characterized in that, Includes the following steps: S1. Identify the construction section at the abandoned coal mine shaft and clean up the construction section; S2. Excavate multiple annular concrete wall trenches at certain intervals in the coal mine shaft construction section; S3. First, pour the innermost ring-shaped concrete wall, then pour the wellhead wall in a ring shape next to the ring-shaped concrete wall to form a seepage-proof cement layer, and finally fill the crushed stone layer. S4. Repeat step S3 to create multiple sets of ring-shaped concrete walls, impermeable cement layers, and crushed stone layers; S5. Construct a brickwork layer at the wellhead and seal the edges around the wellhead with cement.

4. The construction method of the sealing structure for an abandoned coal mine shaft according to claim 3, characterized in that, In step S1, after the construction section is cleaned up, drainage ditches are excavated on both sides of the tunnel to discharge the acidic wastewater.

5. The construction method of the sealing structure for an abandoned coal mine shaft according to claim 3, characterized in that, In step S3, before pouring the impermeable cement layer, high-pressure cement is poured into the leaking area of ​​the wellhead wall.

6. The construction method of a sealing structure for an abandoned coal mine shaft according to claim 5, characterized in that, After high-pressure cement is poured into the leaking area, the wellhead wall is roughened.

7. The construction method of the sealing structure for an abandoned coal mine shaft according to claim 3, characterized in that, In step S3, after the impermeable cement layer and before the crushed stone layer is filled, a reinforced concrete column is cast between adjacent annular concrete walls using a steel cage.

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