CN114575847B - Shallow coal seam water-retaining mining and underground reservoir construction integrated method - Google Patents

Abstract

The invention relates to a method for integrating water retention mining of a shallow coal seam and construction of an underground reservoir, creatively provides filling of a goaf caving zone part to reduce damage to a water-bearing layer, and provides a method for fully filling the goaf caving zone part, wherein a layer of II or III-shaped precast block is paved on a coal seam bottom plate behind a hydraulic support in a row along the inclination, the precast block is adopted and comprises a filling cavity to ensure the construction efficiency and the construction is light, and the strength can be ensured after the filling cavity is filled; the filling construction area is arranged in the return air roadway, so that the construction efficiency can be improved, the interference with coal mining is reduced, and certain self-flow can be realized by utilizing the self-weight; the designed track with a special structure can greatly improve the laying efficiency of the precast blocks and reduce the labor capacity. Meanwhile, the laid precast blocks form a bottom plate water-resisting layer, and a water-proof treatment is performed on the circumferential coal wall in a combined mode, and finally an underground reservoir is formed in the truncated cone-shaped water flowing crack area, so that the mining and underground reservoir construction are protected to be integrated.

Description

An integrated method of shallow coal seam water conservation mining and underground reservoir construction

technical field

The invention relates to the field of water conservation mining in coal mines, in particular to an integrated method for water conservation mining of shallow coal seams and construction of underground reservoirs.

Background technique

my country's underground coal mine development and collection reduction level has been continuously improved, and it has become an important way to improve the safety of coal mines, resource recovery rate and economic benefits. High-intensity mining is an important method of intensive mining, but it brings about rapid surface subsidence and large deformation, which in turn damages the ecology and needs to be solved urgently. The distribution of coal occurrence and ecological environment capacity in my country is uneven. The coal production in western Shanxi, Shaanxi, Mongolia, Ningxia and Gansu, represented by the Shendong mining area, accounts for 3/4 of the country's coal output. However, the region's ecology is fragile, water resources are scarce, and high-intensity mining has caused groundwater pollution. Loss and destruction have exacerbated desertification and desertification in and around the mining area. The surface ecological damage in the mining area is caused by the mining damage of the lower strata caused by the deformation, fracture and movement of the overlying strata caused by coal mining, and the transmission damage of the upper strata and the surface layer. Therefore, the root of ecological restoration in mining areas is to minimize the damage to the surface ecology from the source of mining. The key is to make full use of the damage rules of mining to the overlying rock and the surface, to realize artificial control of damage conduction, and then to achieve efficient restoration of surface ecology and Coordinating with high-intensity mining. However, in the prior art, underground gangue filling mining, high water filling mining, and paste filling mining that control surface damage from the source cannot meet the requirements of high-intensity mining due to large filling volume, high filling cost, and complicated procedures.

Contents of the invention

Aiming at the deficiencies in the above-mentioned prior art, the present invention proposes a method for integrating shallow coal seam water conservation mining and underground reservoir construction, including the following steps:

a. Planning of the mining area, the faults with risk of water conduction are arranged in the coal pillar of the section, the return air roadway on both sides of the excavation face is connected with the transportation roadway and the cutout, and the return air roadway, the transportation roadway and the cutout are connected. Spray concrete on the coal pillar wall and do waterproof treatment;

b. In the air return roadway on the upper side, and in the coal pillar between the production line and the upper mountain, two chambers are constructed. One is used as a temporary storage space for prefabricated blocks, and the other is used as a paste filling transfer station. Build the filling well to the paste filling transfer station, and lay the filling pipeline from the filling transfer station to the filling construction area;

c. The original mining height of the coal seam is M, and the distance from the aquifer is H; the critical mining height of the coal seam is determined to be Mc, so that the height of the water-conducting fissure area under the critical mining height is H _d <H; that is, the water-conducting fissure area does not communicate with water layer, and leave a certain thickness of protective layer between the aquifer and the water-conducting fissure area;

d. The working face advances from the cutting eye to the front, and at the same time, lay a layer of prefabricated blocks with a thickness of M-Mc on the coal seam floor behind the hydraulic support and the corresponding transportation roadway bottom plate at the lower part; the prefabricated block is "II " or "III" shape, and the overall cuboid structure, including the top plate, the bottom plate and the vertical support plate connecting them; between the vertical support plates of the same prefabricated block, the adjacent vertical support plates of two adjacent prefabricated A filling cavity is formed between the support plates; the length direction of the laid prefabricated blocks is arranged in a row along the direction, and the adjacent filling cavities are connected up and down. The opening of the final filling cavity is located in the return air tunnel, that is, the filling construction area is set in Air return roadway, all adjacent prefabricated blocks shall be sealed;

Preferably, adjacent prefabricated blocks are fixed by mortise joints, and tenon joint areas are provided on the top and bottom plate sides of adjacent prefabricated blocks, and grooves and projections for tenon joint are provided in the middle of the tenon joint areas. Further, a sealing strip and a sealing groove are provided on the upper part of the tenon joint area, and a filling sealing groove is provided on the lower part of the tenon joint area, and the sealing material is filled for sealing after the prefabricated blocks are laid.

Preferably, the prefabricated blocks are transported from the air return roadway to the transport roadway, and each column is laid from bottom to top from the transport roadway to the air return roadway. Further, a track along the inclination is laid behind the hydraulic support. The track includes multiple sections. The lower part of each track is provided with rollers that can move along the inclination and direction, and the upper part is provided with fixed rollers that roll along the inclination. Move up and down to the predetermined position, and then move each section of track in the direction of the hydraulic support from bottom to top in order to lay the next row of prefabricated blocks.

e. Fill the filling cavity of the prefabricated blocks laid in step d, and then continue to spread and fill the prefabricated blocks on the bottom plate of the return air tunnel, and ensure that the filling cavity is filled with paste before each cycle of pressing body filling material;

Preferably, the paste filling material achieves set before the cycle is pressed.

The main raw materials used for the paste filling material are one or more of coal gangue, fly ash, washing tailings, and aeolian sand.

f. Reciprocate in this way until the working face is finished;

g. Spray concrete on the wall of the coal pillar near the uphill side of the harvesting line and do waterproof treatment, and close the return air roadway and the transportation roadway at the harvesting line to form an underground reservoir;

h. Construction of water injection well and pumping well from the ground to the underground reservoir, the water injection well is close to the side of the return air roadway, and the pumping well is close to the side of the transportation roadway.

Preferably, casings are arranged in the water injection well and the pumping well, and the part of the casing in the underground reservoir is a floral tube.

Beneficial effects: the present invention relates to an integrated method of shallow coal seam water conservation mining and underground reservoir construction, and creatively proposes to partially fill the gob collapse zone to reduce the actual mining height to reduce damage to the aquifer and realize water conservation Mining, while solving the problem of high cost, low efficiency and heavy workload for all filling. Furthermore, the present invention creatively provides a partial sufficient method for the gob caving zone, laying a layer of II or III prefabricated blocks in a row along the inclination on the coal seam floor behind the hydraulic support, using prefabricated blocks and including filling The cavity guarantees construction efficiency and light construction, while the filling cavity can also ensure strength after filling; setting the filling construction area in the return air tunnel can improve construction efficiency, reduce interference with coal mining, and achieve a certain Self-flowing; and the specially designed track can greatly improve the laying efficiency of prefabricated blocks and reduce the amount of labor. In addition, the filling timing is given, that is, the paste filling material is set before the cycle is pressed, so as to avoid the collapse of the top plate and crush the hollow prefabricated block. At the same time, the laid prefabricated blocks form the water-resisting layer of the floor, combined with the waterproof treatment of the circumferential coal wall, and finally form an underground water reservoir in the circular frustum-shaped water-conducting fissure area, realizing the integration of protected mining and underground water reservoir construction.

Description of drawings

Fig. 1 is a schematic diagram of an integrated method for water conservation mining and underground reservoir construction;

Fig. 2 is the schematic diagram of water conservation exploitation and underground reservoir construction completion;

Fig. 3 is the profile of type II prefabricated block perpendicular to the length direction;

Fig. 4 is an enlarged view of the tenon joint area in Fig. 3;

In the figure, 1-surface; 2-aquifer; 3-protective layer; 4-section coal pillar; 5-working face; -top plate, 82-bottom plate; 83-vertical support plate; 84-tenon joint area; 841-sealant strip and sealing groove; 842-groove and bump; 843-filling sealing groove; 85-filling cavity; 9 - underground water reservoir; 10 - water injection well; 11 - pumping well.

Detailed ways

The technical solutions of the present invention will be described in more detail below in combination with the accompanying drawings in the embodiments of the present invention.

As shown in Figure 1-4, a method for integrating shallow coal seam water conservation mining and underground reservoir construction includes the following steps:

a. Mining area planning, the faults with risk of water conduction are arranged in the coal pillar 4 of the section, the return air roadways on both sides of the excavation working face 5 are connected with the transport roadway and cut holes, and the return air roadway, transport roadway and cutting Spray concrete on the wall of coal pillars with holes and do waterproof treatment;

b. In the air return roadway on the upper side, and in the coal pillar between the production line and the upper mountain, two chambers are constructed. One is used as a temporary storage space for prefabricated blocks, and the other is used as a paste filling transfer station. Construction filling wells to the paste filling transfer station, laying filling pipelines from the paste filling transfer station to the filling construction area;

c. The original mining height of the coal seam is M, and the distance from the aquifer 2 is H; the critical mining height of the coal seam is determined to be Mc, so that the height of the water-conducting fracture zone 6 under the critical mining height H _d <H; that is, the water-conducting fracture zone does not Communicate the aquifer 2 to realize the protection and exploitation of the aquifer, and leave a protective layer 3 with a certain thickness between the aquifer 2 and the water-conducting fissure area 6;

d. The working face advances from the cutting eye to the front, and at the same time, lay a layer of prefabricated blocks 8 with a thickness of M-Mc on the coal seam floor behind the hydraulic support and the corresponding transportation roadway bottom plate at the lower part; the prefabricated block 8 is "II" or "III" shape, and the overall cuboid structure, including a top plate 81, a bottom plate 82 and a vertical support plate 83 connecting the two; between the vertical support plates 83 of the same prefabricated block, two adjacent blocks Filling cavities 85 are formed between the adjacent vertical support plates 83 of the prefabricated blocks; the length direction of the laid prefabricated blocks is arranged in a row along the inclination, and the adjacent filling cavities 85 are connected up and down, and the opening of the final filling cavity is located in the return air In the roadway, another opening is closed in the transportation roadway, that is, the filling construction area is set in the return air roadway, and all adjacent prefabricated blocks are sealed;

Preferably, the adjacent prefabricated blocks 85 are fixed by mortise joints, including between rows and rows and between columns (inclined to line up, and to line up); specifically on the top plate 81 and bottom plate 82 sides of adjacent prefabricated blocks A mortise joint area 84 is provided at the top, and a groove and a protrusion 842 for tenon joint are provided in the middle of the tenon joint area. Further, a sealing strip and a sealing groove 841 are provided on the upper part of the tenon joint area, and a filling sealing groove 843 is provided on the lower part of the tenon joint area, which is used to fill the sealing material for sealing after the prefabricated blocks are laid.

Preferably, the prefabricated blocks are transported from the air return roadway to the transport roadway, and each column is laid from bottom to top from the transport roadway to the air return roadway; further, a track along the inclination is laid behind the hydraulic support, The track consists of multiple sections, the lower part of each track is provided with rollers that can move along the inclination and direction, and the upper part is provided with fixed rollers that roll along the inclination, so as to facilitate the prefabricated blocks to move down to the predetermined position along the fixed rollers, and then from bottom to top Move each section of track to the direction of the hydraulic support to lay the next row of prefabricated blocks.

e. Fill the filling cavity of the prefabricated block laid in step d, then continue to pave and fill the prefabricated block on the bottom plate of the return air tunnel, and ensure that the filling cavity 85 is injected into the filling cavity 85 before each cycle is pressed. Full paste filling material;

Preferably, the paste filling material achieves set before the cycle is pressed.

Preferably, the main raw materials used for the paste filling material are coal gangue, fly ash, washing tailings, aeolian sand and the like.

f. Reciprocate in this way until the working face is finished;

g. Spray concrete on the wall of the coal pillar close to the uphill side of the retraction line and do waterproof treatment, and close the air return roadway and the transportation roadway at the retraction line, so as to form an underground reservoir 9, the lower part of the underground reservoir is a prefabricated block, and the side The lower boundary of the lower portion is the wall of the coal pillar after shotcrete and waterproof treatment, the upper boundary of the side is the stratum caving boundary line 7, and the upper boundary is the bottom plate of the protective layer, that is, the top surface of the water-conducting fissure area;

h. Construction of the water injection well 10 and the pumping well 11 from the ground 1 to the underground reservoir 9. The water injection well 10 is close to the side of the return air roadway, and the pumping well 11 is close to the side of the transport roadway, so that the water can be filtered through the broken rocks in the underground reservoir.

Preferably, a casing is provided in the water injection well 10 and the pumping well 11, and the part of the casing in the underground reservoir is a floral tube.

Claims (5)

1. A method for integrating water retention mining and underground reservoir construction of a shallow coal seam is characterized by comprising the following steps:

a. planning a mining area, arranging fault with water guiding danger in a coal pillar of the section, communicating air return tunnels on two sides of a driving working face with a transportation tunnel and cutting holes, and spraying concrete on the wall surfaces of the air return tunnels, the transportation tunnel and the cutting holes and performing waterproof treatment;

b. constructing two chambers in a coal pillar between a take-up line and an ascending mountain in an upper return air roadway, wherein one chamber is used as a prefabricated block temporary storage space, the other chamber is used as a paste filling transfer station, a filling pipeline is laid from a ground construction filling well to the paste filling transfer station, and a filling construction area is laid from the filling transfer station;

c. the original mining height M of the coal seam is H, and the distance from the coal seam to the aquifer is H; determining the critical mining height of the coal bed to be Mc, so that the height H of the water flowing fracture area under the critical mining height _d <H; the water-flowing fractured zone is not communicated with the aquifer, and a protective layer with a certain thickness is reserved between the aquifer and the water-flowing fractured zone;

d. the working face is pushed forwards along the trend from the cutting hole, and meanwhile, precast blocks with the thickness of M-Mc are paved on the coal seam floor behind the hydraulic support and the corresponding transportation roadway floor at the lower part; the prefabricated block is in a shape of II or III, is integrally in a cuboid structure and comprises a top plate, a bottom plate and a vertical supporting plate for connecting the top plate and the bottom plate; filling cavities are formed between the vertical supporting plates of the same precast block and between the adjacent vertical supporting plates of the two adjacent precast blocks; the length direction of the laid precast blocks is arranged in a row along the coal seam inclination, the upper and lower adjacent filling cavities are communicated, the opening of the final filling cavity is positioned in the air return roadway, namely, the filling construction area is arranged in the air return roadway, and all the adjacent precast blocks are sealed;

e. d, filling the filling cavity of the prefabricated block laid in the step d, then continuously paving the prefabricated block on the bottom plate of the return air roadway and filling, and ensuring that paste filling materials are filled into the filling cavity before periodic pressure is applied every time;

f. repeating the steps until the working surface is picked;

g. spraying concrete on the wall surface of the coal pillar close to the upper mountain side of the collection line, performing waterproof treatment, and sealing an air return roadway and a transportation roadway at the collection line to form an underground reservoir;

h. and (3) constructing a water injection well and a water pumping well from the ground to the underground water reservoir, wherein the water injection well is close to the air return roadway side, and the water pumping well is close to the transportation roadway side.

2. The method of claim 1, wherein in step d, the adjacent prefabricated blocks are fixed in a joggle mode, the side parts of the top plate and the bottom plate of the adjacent prefabricated blocks are provided with joggle areas, the middle parts of the joggle areas are provided with grooves and protrusions for joggling, the upper parts of the joggle areas are provided with sealing rubber strips and sealing grooves, the lower parts of the joggle areas are provided with filling sealing grooves, and the prefabricated blocks are filled with sealing materials for sealing after being laid.

3. The method of claim 1, wherein the paste-fill material is allowed to set before the periodic pressurization in step e.

4. The method for integrating water conservation exploitation of a shallow coal seam with construction of an underground reservoir as claimed in claim 1, wherein in the step e, the paste filling material is one or more of coal gangue, fly ash, washing tailings and aeolian sand.

5. The method for integrating water conservation exploitation with an underground reservoir of a shallow coal seam as claimed in claim 1, wherein in the step h, sleeves are arranged in the water injection well and the water pumping well, and the part of the sleeves in the underground reservoir is floral tubes.

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