A coal mine underground main drainage system sump deformation string sump treatment process

Abstract

The present application belongs to the technical field of coal mine underground main drainage system, and discloses a coal mine underground main drainage system sump deformation string sump treatment process. The process effectively solves the problem of water string between internal and external sumps caused by the fact that the traditional sump treatment process does not consider the stress transmission between sump groups. The process comprises: during construction, a temporary water storage sump with double water retaining walls and multiple standby pumps is used, including the construction of internal and external water retaining walls, the installation of multiple submersible pumps, and the laying of multiple water feeding pipelines to the main drainage pump; a hierarchical three-dimensional grouting method is constructed: roof deep hole grouting; surrounding rock deep hole grouting, which is divided into multiple rounds of grouting, and the multiple rounds of pressure grouting process adopts a "grouting-hole casing drilling-regrouting" cycle; sump wall shallow hole grouting; three drill sites are designed for the grouting reinforcement of the sump block surrounding rock. The present application can achieve an effective sump cross section recovery rate of 90% or more, a water string channel plugging rate of 100%, a reduction in rock column permeability coefficient, and an extension of the service life of the support structure.

Description

Technical Field

[0001] This invention belongs to the technical field of underground main drainage systems in coal mines, and particularly relates to a process for treating deformation and cross-contamination of water tanks in underground main drainage systems in coal mines. Background Technology

[0002] The main drainage system in coal mines, as a core facility for safe production, consists of pump houses, water tanks, substations, and other components. Under the long-term effects of mining dynamic pressure, the main drainage system's tanks and roadways will experience severe deformation and damage: the concrete arch structure of the main drainage tank will be damaged; water will seep between the inner and outer water tanks; the pump house roof will subside, causing pipeline deformation; the water distribution roadways will deform, gate valves will be damaged, and severe water seepage will occur. If this continues to deteriorate, it will lead to a complete collapse, seriously threatening the safe production of the coal mine.

[0003] Traditional water tank treatment processes have the following technical defects: (1) Single grouting reinforcement does not take into account the stress transfer between water tank groups, resulting in water leakage between inner and outer water tanks; (2) Conventional support cannot resist continuous mining deformation, and concrete masonry arch structures are prone to progressive damage; (3) The narrow space of the water distribution tunnel is not thoroughly reinforced, and the gate valve is at high risk of pressure failure. Summary of the Invention

[0004] The purpose of this invention is to provide a process for treating deformation and cross-contamination of water sumps in the main drainage system of underground coal mines, which effectively solves the problem of cross-contamination of water between inner and outer water sumps caused by the failure of traditional water sump treatment processes to consider stress transmission between water sump groups.

[0005] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is: a process for treating deformation and cross-contamination of water tanks in the main drainage system of underground coal mines, comprising the following steps.

[0006] S1. Establish a dynamic drainage guarantee system: During construction, a temporary water storage tank with double water-retaining walls and multiple backup pumps is adopted, including the construction of inner and outer water-retaining walls, the installation of multiple submersible pumps, and the laying of multiple water supply pipelines to the main drainage pump, so that the main drainage pump can drain water without passing through the water tank, leaving the water tank empty.

[0007] S2. Construct a graded three-dimensional grouting method: adopt a "deep-medium-shallow" graded grouting reinforcement, including: deep hole grouting of the roof; medium-deep hole grouting of the surrounding rock, in multiple rounds of grouting, with the multi-round pressure grouting process adopting a "grouting-sleeve drilling-re-grouting" cycle; and shallow hole grouting of the silo wall.

[0008] S3, the design of grouting reinforcement of the surrounding rock of the water tank block includes three drilling sites: the outer end of the -440 main rail secondary downhill bottom yard, the roadway at the northeast intersection of the two water tanks, and the outer water tank. The corresponding reinforcement areas are the water tank pump house, the inner ring surrounding rock of the inner water tank, and the surrounding rock of the outer water tank.

[0009] Furthermore, in step S2, the depth of the deep holes in the roof is 28.5-29m, and the grouting pressure is 1.5-3MPa; the depth of the medium-deep holes in the surrounding rock is 20-60m, and the length of a single grouting section is 20-30m; the depth of the shallow holes in the silo wall is 2.5m, and the grout diffusion radius is 2.0m.

[0010] Furthermore, the grout is a cement-water glass composite grout with a weight ratio of cement:water glass = 1:0.06 and a water-cement ratio of 1.5:1; the initial injection pressure is 1.5MPa and the final pressure is 3.0MPa.

[0011] Furthermore, in step S1, the height of the inner retaining wall is 0.5m, the height of the outer retaining wall is 1.7m, and the rated flow rate of the submersible pump is 100m³. 3 / h.

[0012] Furthermore, in step S2, the arrangement of grouting holes satisfies a row spacing of 2.5m ± 0.2m and an adjacent row spacing of ≥ 1.2m, forming a plum blossom pile pattern.

[0013] Furthermore, in step S1, the temporary water storage tank has a capacity of 30-50m³. 3 / h buffer capacity and ≥150m 3 / h of emergency drainage capacity.

[0014] Furthermore, in step S2, the deep hole grouting of the top plate adopts a sequential operation, first constructing odd-numbered holes, and then constructing even-numbered holes 48 hours later; the shallow hole grouting of the silo wall is constructed in two rounds, with the first round hole depth being 2.0m and the second round hole depth being 2.5m, and the grout vein coverage rate being ≥85%.

[0015] Furthermore, in step S3, the grouting reinforcement zone of the outer water tank extends to the top plate of the inner tank, with a single hole depth of 31-43m and a total drilling depth of 677m; the grouting reinforcement zone of the inner ring of the inner water tank has a single hole depth of 60-135m, a total drilling depth of 279m, and a sweeping depth of 507m.

[0016] Furthermore, it is applicable to the comprehensive treatment of water leakage in concrete masonry arch structures under high stress environments.

[0017] Compared with the prior art, the beneficial technical effects of the present invention are: (1) The present invention addresses the problem of water leakage in double water tanks and water distribution tunnels, taking into account factors such as water tank deformation, cleaning, space, and time. It adopts a temporary water storage tank with double water retaining walls and three backup pumps, and a grouting design behind the tank tunnel walls, which strengthens the surrounding rock while achieving seepage prevention. The present invention can achieve an effective cross-sectional restoration rate of ≥90% for the water tank, a water leakage channel blocking rate of 100%, a reduction in the rock column permeability coefficient, and an extension of the service life of the support structure. Compared with traditional methods, the present invention can improve the bearing capacity of the support structure, shorten the construction cycle, and effectively solve the problems of surrounding rock reinforcement and water leakage in water tank groups under high stress conditions.

[0018] (2) This invention is beneficial to the structural repair and functional restoration of deformed water tanks in the main drainage system, effectively solves the problem of deformation of coal mine water tanks, improves the stability and safety of drainage systems, and promotes technological progress in the industry. Attached Figure Description

[0019] Figure 1 This is a temporary drainage route map for emptying and clearing the warehouse.

[0020] Figure 2 This is a schematic diagram of the drilling site location.

[0021] Figure 3 This is a diagram showing the layout of deep-hole grouting drill holes in the pump house roof.

[0022] Figure 4 This is a diagram showing the drilling layout for grouting reinforcement of the inner ring of the inner water tank.

[0023] Figure 5 This is a diagram showing the layout of boreholes for grouting reinforcement of the surrounding rock of the outer water tank.

[0024] Figure 6 This is a diagram showing the layout of the plum blossom-shaped grouting holes in the walls of the outer water tank and the water distribution tunnel. Detailed Implementation

[0025] Example 1: The 670m level drainage system of Coal Mine A was subjected to long-term dynamic pressure from mining, resulting in severe deformation and damage to the system's storage tunnels: the concrete arch structure of the main drainage tunnel was damaged, with the net width reduced from 3m to 2.8m and the net height reduced from 3.1m to 2.5m; water flow occurred between the inner and outer water tanks; the pump house roof subsided, causing pipeline deformation; the water distribution tunnel was deformed, the gate valves were damaged, and there was severe water seepage.

[0026] For the 670m horizontal drainage system of Coal Mine A, this embodiment provides a corresponding treatment process for deformation and cross-contamination of the water sump in the main underground drainage system of the coal mine, which specifically includes the following steps.

[0027] S1. Establish a dynamic drainage system: Empty and clear the storage area before construction, such as... Figure 1As shown, a temporary water storage tank is set up in the northeast direction of the water measuring point 1 in the -670 main roadway. The temporary water storage tank adopts a double water-retaining wall and three backup pumps, including the construction of an inner water-retaining wall and an outer water-retaining wall. The height of the inner water-retaining wall is 0.5m, and the height of the outer water-retaining wall is 1.7m. Three pumps with a rated flow rate of 100m³ / h are installed. 3 A submersible pump with a capacity of / h is used, and three water supply lines are laid to the main drainage pump, such as... Figure 1 As indicated by the middle arrow, water is pumped through three pipelines to the -350 level by the main drainage pump; the temporary water storage tank is filled with water at a flow rate of 30-50 m³ / h. 3 / h, emergency drainage capacity 300m 3 / h.

[0028] S2. Construct a graded three-dimensional grouting method: adopt a graded grouting reinforcement method of "deep-medium-shallow", including: (1) Deep hole grouting of the top plate: the hole depth is 28.5-29m, and the grouting pressure is 1.5-3MPa. The deep hole grouting of the top plate adopts a sequential operation, first constructing odd-numbered holes, and then constructing even-numbered holes 48 hours later.

[0029] (2) Deep hole grouting in surrounding rock: The hole depth is 20-60m, and grouting is carried out in multiple rounds. The length of a single round of grouting is 20-30m. The multi-round pressure grouting process adopts the cycle of "grouting-hole drilling-re-grouting".

[0030] (3) Shallow hole grouting of the silo wall: The hole depth is 2.5m, the row spacing is 2.5m, the hole layout is quincunx, and the grout diffusion radius is 2.0m. The shallow hole grouting of the silo wall is carried out in two rounds. The first round hole depth is 2.0m, and the second round hole depth is 2.5m. The grout vein coverage rate is ≥85%.

[0031] In step S2, the arrangement of grouting holes meets the requirements of a row spacing of 2.5m ± 0.2m and an adjacent row spacing of ≥ 1.2m, forming a plum blossom pile pattern.

[0032] S3, the design of grouting reinforcement for the surrounding rock of the water reservoir block, three drilling sites, such as Figure 2 As shown, the area includes: the outer end of the -440 main track secondary downhill bottom yard (Drilling Site 1), the roadway at the northeast intersection of the two water tanks (Drilling Site 2), and the middle of the outer water tank (Drilling Site 3). The corresponding reinforcement areas are the water tank pump house, the inner ring surrounding rock of the inner water tank, and the surrounding rock of the outer water tank.

[0033] In step S3, (1) the pump house roof is reinforced: such as Figure 3 As shown in Table 1, six grouting holes (hole numbers 1-1 to 1-6) are arranged, with the hole opening point 2.5m from the bottom plate. Hole 1-1 is 62m from the roadway intersection, and the depth of a single hole is 28.5-29m. The grouting process is as follows: fixed mix pressure → grouting → casing drilling and grouting → sealing.

[0034] Table 1 Drilling Parameters for Grouting Reinforcement of Pump House Roof (2) Reinforcement of the surrounding rock within the inner water tank: such as Figure 4 As shown in Table 2, three grouting holes were set up (hole numbers 2-1, 2-2, and 2-3), with a single hole depth of 60-135m. Multiple rounds of construction were carried out, with each round consisting of a grouting section of 20-30m. The process was as follows: fixed mix pressure → grouting → casing drilling and re-grouting → hole sealing. The total drilling footage was 279m, and the sweeping footage was 507m.

[0035] Table 2 Drilling Parameters for Grouting Reinforcement of Inner Ring of Inner Water Chamber (3) Reinforcement of the surrounding rock of the external water tank: such as Figure 5 As shown in Table 3, 18 grouting holes (hole numbers 3-1 to 3-18) were used to reinforce the top of the inner chamber. The depth of each hole was 31-43m. Two rounds of construction were carried out, with a total drilling footage of 677m. The process was as follows: fixed mix pressure → grouting → casing drilling and grouting → sealing.

[0036] Table 3 Drilling Parameters for Grouting Reinforcement of Surrounding Rock in External Water Tank (4) Grouting reinforcement of the outer water tank and water distribution tunnel wall: 406 grouting holes, 2.5m deep, two rounds of construction, the process is fixed mix pressure → grouting → casing drilling and grouting → sealing.

[0037] (5) Water tank wall reinforcement: Grouting holes are arranged in rows with a row spacing of 2.5m. The outer water tank and the water distribution tunnel are arranged with holes in a specific manner, such as... Figure 6 As shown, it is in the shape of plum blossom piles, with two rounds of grouting. The process is as follows: fixed mix ratio pressure → grouting → casing drilling and grouting → sealing the hole.

[0038] In this embodiment, the grout is a cement-water glass composite grout with a weight ratio of cement:water glass = 1:0.06 and a water-cement ratio of 1.5:1. The initial injection pressure is 1.5 MPa and the final pressure is 3.0 MPa.

[0039] The treatment process provided in this embodiment ultimately achieves an effective cross-sectional restoration rate of ≥90% for the water tank, a 100% blockage rate for water passage channels, and a reduction in the permeability coefficient of the rock column. This treatment process is applicable to the comprehensive treatment of water passage in concrete masonry arch structures under high stress environments, and is particularly suitable for underground drainage systems in coal mines affected by mining dynamic pressure.

[0040] Of course, the above description is not intended to limit the present invention, and the present invention is not limited to the examples given above. Any changes, modifications, additions or substitutions made by those skilled in the art within the scope of the present invention should also fall within the protection scope of the present invention.

Claims

1. A process for treating deformation and cross-contamination of water sump in the main drainage system of an underground coal mine, characterized in that, Includes the following steps: S1. Establish a dynamic drainage guarantee system: During construction, a temporary water storage tank with double water-retaining walls and multiple backup pumps is adopted, including the construction of inner and outer water-retaining walls, the installation of multiple submersible pumps, and the laying of multiple water supply pipelines to the main drainage pump, so that the main drainage pump can drain water without passing through the water tank and the water tank is left empty. S2. Construct a graded three-dimensional grouting method: adopt a "deep-medium-shallow" graded grouting reinforcement, including: deep hole grouting of the roof; medium-deep hole grouting of the surrounding rock, in multiple rounds of grouting, with the multi-round pressure grouting process using a "grouting-sleeve drilling-re-grouting" cycle; shallow hole grouting of the silo wall; S3, the design of grouting reinforcement of the surrounding rock of the water tank block includes three drilling sites: the outer end of the -440 main rail secondary downhill bottom yard, the roadway at the northeast intersection of the two water tanks, and the outer water tank. The corresponding reinforcement areas are the water tank pump room, the inner ring surrounding rock of the inner water tank, and the surrounding rock of the outer water tank. In step S2, the depth of the deep holes in the roof is 28.5-29m, and the grouting pressure is 1.5-3MPa; the depth of the medium-deep holes in the surrounding rock is 20-60m, and the length of a single grouting section is 20-30m; the depth of the shallow holes in the silo wall is 2.5m, with a quincunx pattern of holes and a grout diffusion radius of 2.0m.

2. The process for treating deformation and cross-contamination of water tanks in a coal mine underground main drainage system according to claim 1, characterized in that, The grouting slurry is a cement-water glass composite slurry with a weight ratio of cement:water glass = 1:0.06 and a water-cement ratio of 1.5:

1. The initial injection pressure is 1.5 MPa and the final pressure is 3.0 MPa.

3. The process for treating deformation and cross-contamination of water tanks in a main drainage system of an underground coal mine according to claim 2, characterized in that, In step S1, the height of the inner retaining wall is 0.5m, the height of the outer retaining wall is 1.7m, and the rated flow rate of the submersible pump is 100m³ / h. 3 / h.

4. The process for treating deformation and cross-contamination of water tanks in a coal mine underground main drainage system according to claim 3, characterized in that, In step S2, the arrangement of grouting holes meets the requirements of a row spacing of 2.5m ± 0.2m and an adjacent row spacing of ≥ 1.2m, forming a plum blossom pile pattern.

5. The process for controlling deformation and cross-contamination of water tanks in a coal mine underground main drainage system according to claim 4, characterized in that, In step S1, the temporary water storage tank has a capacity of 30-50m³. 3 / h buffer capacity and ≥150m 3 / h of emergency drainage capacity.

6. The process for controlling deformation and cross-contamination of water tanks in a coal mine underground main drainage system according to claim 5, characterized in that, In step S2, the deep hole grouting of the top plate is carried out in sequence, with odd-numbered holes constructed first, and even-numbered holes constructed 48 hours later; the shallow hole grouting of the silo wall is carried out in two rounds, with the first round hole depth being 2.0m and the second round hole depth being 2.5m, and the grout vein coverage rate being ≥85%.

7. The process for treating deformation and cross-contamination of water tanks in a coal mine underground main drainage system according to claim 6, characterized in that, In step S3, the grouting reinforcement zone of the outer water tank extends to the top plate of the inner tank, with a single hole depth of 31-43m and a total drilling depth of 677m; the grouting reinforcement zone of the inner ring of the inner water tank has a single hole depth of 60-135m, a total drilling depth of 279m, and a sweeping depth of 507m.

8. The process for treating deformation and cross-contamination of water tanks in a coal mine underground main drainage system according to claim 7, characterized in that, It is applicable to the comprehensive treatment of water leakage in concrete masonry arch structures under high stress environments.

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