Mine sealing method and structure thereof

Abstract

The present invention relates to a mine plugging method and structure thereof, which uses roughening and grooving of cave walls, brickwork, temporary water diversion, clay filling, and concrete plugging of wellheads to plug the mine. The present invention sets a clay filling section before the concrete plugging section, and performs interval grooving around the cave wall of the set clay filling section, which can ensure that the filled clay is completely combined with the cave wall to prevent water seepage; to ensure that the clay filling is dense, brickwork is set at both ends of the clay filling section, and the brickwork is tightly attached to the cave wall to prevent seepage. The technical solution of the present invention is safe, reliable, efficient, and fast, and complies with relevant national technical specifications, greatly improving the airtightness and firmness of the plugging of mine water gushing, and eliminating the environmental pollution risk of abandoned mine water gushing.

Description

Technical Field

[0001] The invention relates to the technical field of mine plugging, in particular to a mine plugging method and a structure thereof. Background Art

[0002] At present, abandoned mines that are no longer in use need to be sealed. After the mines are sealed, the groundwater level in the original affected area will recover to a certain extent, and the groundwater discharge path will also change. Controlled by the terrain in the area, the groundwater level will rise and discharge in the form of descending springs on the slopes or steep cliffs above the mine, or discharge to the local erosion base surface. In the early stage of mine sealing, before the water level rises to the carbonate aquifer, the water quality of groundwater discharged to the surface will still exceed the standard to varying degrees, and there will be a certain degree of environmental impact. The commonly used concrete sealing method is not ideal for sealing water gushing, and the sealed mines still have great environmental risks. Summary of the invention

[0003] In order to overcome the shortcomings of mine plugging in the background technology, the present invention provides a mine plugging method and structure thereof.

[0004] The technical solution adopted by the present invention to solve the technical problem is: a mine plugging method, which uses a construction method of roughening and grooving the cave wall, brickwork, temporary water diversion, clay filling and concrete plugging the wellhead to plug the mine, including the following steps:

[0005] 1) Wellhead cleaning: clean up the silted soil at the wellhead section and review the geological conditions of the wellhead section;

[0006] 2) Roughening and grooving of the tunnel wall: roughening the weathered layer of the tunnel wall in the mine until it reaches the fresh rock layer; setting the position and length of the clay filling section in the mine, and making interval grooves around the tunnel wall in the set clay filling section; this can ensure that the filled clay is completely combined with the tunnel wall to prevent water seepage;

[0007] 3) Concrete cushion: Lay a concrete cushion on the working surface at the bottom of the mine hole;

[0008] 4) Brickwork: Brickwork is set up at the inner end of the clay filling section away from the wellhead, and ensure that the brickwork is in close contact with the mine wall; ensure that the clay filling is dense, keep the brickwork in close contact with the mine wall, and prevent water seepage;

[0009] 5) Temporary water diversion: During brickwork construction, water diversion pipes are set up to divert water gushing out of the mine. The position of the water diversion pipes is higher than the siltation soil in the mine, and gate valves are set on the water diversion pipes. They are used to prevent water from flooding the construction area and ensure the construction quality. Water diversion pipes are set up to divert water gushing out of the mine cave during brickwork and clay filling construction.

[0010] 6) Clay filling: Fill the clay filling section in the mine where step 3) roughening and groove carving of the cave wall has been completed;

[0011] 7) Concrete plugging of the wellhead: After the clay filling is completed, the outer end of the clay filling section is sealed by building brick masonry; the gate valve on the water pipe is closed, and then the water pipe outside the gate valve is densely filled with clay to isolate water, and then the part of the water pipe outside the mine hole is cut off; C30 corrosion-resistant concrete is poured at the mine hole to form a concrete pouring plugging section, and the water pipe and gate valve are poured together in the mine to complete the plugging of the wellhead.

[0012] Further preferably, the length of the clay filling section set in step 2) should satisfy the following formula requirements:

[0013] L1≥P*K S *K / (A*γ*Q)

[0014] Where, L1: length of clay filling section (m), P: water pressure near the wellhead (Kpa), A: cross-sectional area of ​​the wellhead (㎡), K S : Clay permeability coefficient (cm / s), γ: Clay density (t / m 3 ), Q: water inflow from wellhead (m 3 / d), K: safety factor.

[0015] Furthermore, in step 7) the wellhead is sealed with concrete, and the length of the concrete sealing section should meet the following requirements:

[0016] L ≥ P*A*K / (C*frb)

[0017] In the formula, L: length of the concrete sealing section of the water wellhead (m), P: water pressure near the water wellhead (Kpa), A: cross-sectional area of ​​the water wellhead (㎡), K: safety factor, C: cross-sectional circumference of the water wellhead (m), Frb: characteristic value of the bond strength between the cave wall and concrete (Kpa).

[0018] Furthermore, the brick masonry constructed in step 4) has a compressive strength of not less than M10 and a thickness of not less than 0.24 m.

[0019] Furthermore, in step 6), before clay filling, the clay needs to be fully mixed after adding water, and the clay is filled manually in layers, with a layer thickness of no more than 20CM. The clay is compacted during filling, and the compaction coefficient is no less than 0.85.

[0020] On the other hand, the present invention proposes a mine sealing structure, including a mine and a concrete sealing section arranged in the mine, and also including a clay filling section and a water pipe arranged in the mine, the clay filling section is arranged in front of the concrete sealing section, the clay filling section is filled with clay, and brick masonry for sealing is provided at both ends of the clay filling section; in the clay filling section, spaced grooves are provided on the roughened inner wall of the mine, the water pipe runs through the clay filling section and the concrete sealing section, and a gate valve is provided on the water pipe.

[0021] Furthermore, the inner wall of the mine shaft in the concrete plugging section is roughened to ensure that the filled concrete is completely integrated with the tunnel wall and prevent water seepage.

[0022] Furthermore, a concrete cushion layer is provided on the ground of the mine within the clay filling section and the concrete blocking section, so as to facilitate the cleaning of the accumulated water on the working surface and ensure the blocking construction effect.

[0023] Furthermore, the water pipe is set at a position higher than the silt soil in the mine. The water pipe is a PPR pipe with a diameter greater than 75 mm, which meets the drainage requirements of the working surface construction process, maintains the stability of the clay filling section and the concrete sealing section, and prevents water accumulation on the working surface. The PPR pipe is corrosion-resistant and durable.

[0024] Furthermore, the compressive strength of the brick masonry is not less than M10 and the thickness is not less than 0.24M, so that the clay filling section is kept dense and stable, and the brick masonry is tightly attached to the surrounding walls of the cave to prevent seepage.

[0025] Furthermore, the water pipe is not easily blocked and can drain water quickly, thus maintaining the stability of the construction of the clay filling section and the concrete sealing section.

[0026] Furthermore, the compaction coefficient of the clay in the clay filling section is not less than 0.85, ensuring that the clay filling section formed by the clay filling has a good water blocking effect.

[0027] The beneficial effects of the present invention are as follows: the method of the present invention is innovative on the basis of the existing concrete plugging, a clay filling section is set before the concrete plugging section, and interval grooves are carved around the set clay filling section cave wall; it can ensure that the filled clay is completely combined with the cave wall to prevent water seepage; to ensure that the clay filling is dense, brick masonry is set at both ends of the clay filling section, and the brick masonry is tightly attached to the cave wall to prevent seepage. The depth of the clay filling section is determined according to the permeability coefficient of the clay, the water pressure of the wellhead cross-sectional area, and the parameters of the mine wellhead cross-sectional area, thereby ensuring the plugging effect.

[0028] In order to prevent water from accumulating in the construction area and ensure the construction quality, water pipes are set up before the construction of brickwork and clay filling to divert the water gushing out of the mine cave, and gate valves are installed on the water pipes to shut off the water after blocking.

[0029] Clay filling is carried out by artificial filling in layers with a layer thickness of no more than 20 cm. The clay is compacted during filling with a compaction coefficient of no less than 0.85 to ensure that the clay forms a water-blocking effect in the clay filling section.

[0030] The inner wall of the mine has been roughened to ensure that the filling clay and concrete are completely integrated with the cave wall to prevent water seepage.

[0031] The technical solution of the present invention is safe, reliable, efficient and fast, complies with relevant national technical specifications, greatly improves the airtightness and firmness of the sealing of mine water gushing, has high safety and reliability, and eliminates the environmental pollution risk of abandoned mine water gushing. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 is a schematic diagram of the structure of the invention;

[0033] Figure 2 is a schematic diagram of Embodiment 2 of the present invention;

[0034] Figure 3 It is a schematic diagram of Example 3 of the present invention.

[0035] Parts and numbers in the picture:

[0036] 1- Mine; 2- Concrete sealing section; 21- Interval groove; 3- Clay filling section; 4- Water pipe; 41- Gate valve; 5- Brickwork. DETAILED DESCRIPTION

[0037] The present invention is further described below in conjunction with the accompanying drawings and embodiments, but is not intended to limit the present invention. Any technical solution based on the transformation or inference of the present invention belongs to the protection scope of the present invention.

[0038] As shown in the embodiment of the present invention and the accompanying drawings, a mine plugging method is used to plug the mine by roughening and grooving the cave wall, brickwork, temporary water diversion, clay filling, and concrete plugging of the wellhead, including the following steps:

[0039] 1) Wellhead cleaning: clean up the silted soil at the wellhead section and review the geological conditions of the wellhead section;

[0040] 2) Roughening and grooving of the tunnel wall: roughening the weathered layer of the tunnel wall in the mine until it reaches the fresh rock layer; setting the position and length of the clay filling section in the mine, and making interval grooves around the tunnel wall in the set clay filling section; this can ensure that the filled clay is completely combined with the tunnel wall to prevent water seepage;

[0041] 3) Concrete cushion: The bottom section of the mine is roughened and then the concrete cushion is laid;

[0042] 4) Brickwork: Brickwork is set up at the inner end of the clay filling section away from the wellhead, and ensure that the brickwork is in close contact with the mine wall; ensure that the clay filling is dense to prevent water seepage;

[0043] 5) Temporary water diversion: During the construction of brickwork, a water diversion pipe is set up to divert the water gushing out of the mine. The position of the water diversion pipe is higher than the siltation soil in the mine, and a gate valve is set on the water diversion pipe; it is used to prevent water from flooding the construction area and ensure the construction quality. During the construction of brickwork and clay filling, a water diversion pipe is set up to divert the water gushing out of the mine cave. The pipe diameter is greater than 75mm, and the position of the water diversion pipe interface is higher than the siltation soil in the cave;

[0044] 6) Clay filling: Fill the clay filling section in the mine where step 3) roughening and groove carving of the cave wall has been completed;

[0045] 7) Concrete plugging of the wellhead: After the clay filling is completed, the outer end of the clay filling section is sealed by building brick masonry; the gate valve on the water pipe is closed, and then the water pipe outside the gate valve is densely filled with clay to isolate water, and then the part of the water pipe outside the mine hole is cut off; C30 corrosion-resistant concrete is poured at the mine hole to form a concrete pouring plugging section, and the water pipe and gate valve are poured together in the mine to complete the plugging of the wellhead.

[0046] The length of the clay filling section in step 2) should meet the following requirements:

[0047] L1≥P*K S *K / (A*γ*Q)

[0048] Where, L1: length of clay filling section (m), P: water pressure near the wellhead (Kpa), A: cross-sectional area of ​​the wellhead (㎡), K S : Clay permeability coefficient (cm / s), γ: Clay density (t / m 3 ), Q: water inflow from wellhead (m 3 / d), K: safety factor.

[0049] In step 7), the wellhead is sealed with concrete, and the length of the concrete sealing section should meet the following requirements:

[0050] L ≥ P*A*K / (C*frb)

[0051] In the formula, L: length of the concrete sealing section of the water wellhead (M), P: water pressure near the water wellhead (Kpa), A: cross-sectional area of ​​the water wellhead (㎡), K: safety factor, C: cross-sectional circumference of the water wellhead (M), Frb: characteristic value of the bond strength between the cave wall and concrete (Kpa).

[0052] The compressive strength of the brick masonry in step 4) is not less than M10 and the thickness is not less than 0.24m.

[0053] In step 6), before clay filling, the clay needs to be fully mixed after adding water, and the clay is filled manually in layers with a layer thickness of no more than 20CM. The clay is compacted during filling with a compaction coefficient of no less than 0.85.

[0054] like Figure 1-3 As shown, a mine plugging structure includes a mine 1 and a concrete plugging section 2 arranged in the mine 1, and also includes a clay filling section 3 and a water guide pipe 4 arranged in the mine 1, wherein the clay filling section 3 is arranged in front of the concrete plugging section 2, the clay filling section 3 is filled with clay, and brick masonry 5 for sealing is provided at both ends of the clay filling section 3; in the clay filling section 3, the inner wall of the mine 1 that has been roughened is provided with interval grooves 21, the water guide pipe 4 passes through the clay filling section 3 and the concrete plugging section 2, and the water guide pipe 4 is provided with a gate valve 41.

[0055] The inner wall of the mine shaft 1 of the concrete plugging section 2 is roughened to ensure that the filled concrete is completely combined with the cave wall to prevent water seepage.

[0056] A concrete cushion layer is provided on the ground of the mine 1 within the clay filling section 3 and the concrete plugging section 2, so as to facilitate the cleaning of the accumulated water on the working surface and ensure the plugging construction effect.

[0057] The water pipe 4 is set at a position higher than the silt soil in the mine 1. The water pipe 4 is a PPR pipe with a diameter greater than 75 mm, which meets the drainage requirements of the working surface construction process, maintains the stability of the construction of the clay filling section 3 and the concrete sealing section 2, and prevents water accumulation on the working surface. The PPR pipe is corrosion-resistant and has good durability.

[0058] The compressive strength of the brickwork 5 is not less than M10 and the thickness is not less than 0.24M, so as to keep the clay filling of the clay filling section 3 dense and stable, and the brickwork is in close contact with the surrounding walls of the cave to prevent seepage.

[0059] The water pipe 4 is not easy to be blocked and can drain water quickly, thereby maintaining the stability of the construction of the clay filling section 3 and the concrete sealing section 2.

[0060] The compaction coefficient of the clay in the clay filling section 3 is not less than 0.85, so as to ensure that the clay filling section 3 formed by the clay filling has a good water blocking effect.

[0061] Example 1

[0062] like Figure 1 As shown in the figure, the mine plugging structure of No. 3 shaft of Yongqing Coal Mine in Shuanghui Town, Wangcang County, Sichuan Province, adopts the construction technology of roughening and grooving the cave wall, brickwork, temporary water diversion, clay filling, and concrete plugging of the wellhead to plug the water gushing from Mine 1. The specific implementation includes the following construction steps:

[0063] 1) Wellhead cleaning: clean up the silted soil in the wellhead section 1 and review the geological conditions of the wellhead section 1;

[0064] 2) Roughening and grooving of the tunnel wall: roughening the weathered layer of the tunnel wall in the mine 1 to the fresh rock layer; setting the position and length of the clay filling section 3 in the mine, and setting interval grooves 21 around the set clay filling section 3 tunnel wall, and performing interval grooves 21 around the set clay filling section 3 tunnel wall; this can ensure that the filled clay is completely combined with the tunnel wall to prevent water seepage;

[0065] The length of clay filling section 3 should meet the following requirements: L1 ≥ P*K S *K / (A*γ*Q)

[0066] Where, L1: length of clay filling section 3 (m), P: water pressure near the wellhead (Kpa), A: cross-sectional area of ​​the wellhead (㎡), K S : Clay permeability coefficient (cm / s), γ: Clay density (t / m 3 ), Q: water inflow from wellhead (m 3 / d), K: safety factor;

[0067] The water pressure near the wellhead of No. 3 well is 1000KPa, and the cross-sectional area of ​​the wellhead is 2*2=4m 2 , the permeability coefficient of clay is 5*10 -5 cm / s, clay weight is 1.64t / m 3 , the water inflow at the wellhead is 450m 3 / d, the safety factor is 2, and the length of the clay filling section 3 of well 3# is L1=2.94m. That is, the length of the clay filling section 3 is not less than 2.94m;

[0068] 3) Concrete cushion: The bottom section of Mine 1 is roughened and then a concrete cushion is laid to facilitate the cleaning of water and silt in the construction area;

[0069] 4) Brickwork: Brickwork 5 is set at the inner side of the clay filling section 3 away from the wellhead of the mine 1, and the brickwork 5 is ensured to be in close contact with the wall of the mine 1; the clay filling is ensured to be dense to prevent water seepage;

[0070] 5) Temporary water diversion: During the construction of the brickwork 5, a water diversion pipe 4 is set to divert the water gushing out of the mine 1. The water diversion pipe 4 is located higher than the siltation soil in the mine 1, and a gate valve 41 is set on the water diversion pipe 4; the water diversion pipe 4 runs through the clay filling section 3 and the concrete blocking section 2 to prevent water from accumulating on the construction area and ensure the construction quality. The diameter of the water diversion pipe 4 is greater than 75 mm, and the interface of the water diversion pipe 4 is located higher than the siltation soil in the cave;

[0071] 6) Clay filling: Fill the clay filling section 3 where the wall roughening and groove carving in step 3) have been completed in the mine with clay;

[0072] 7) Concrete plugging of the wellhead: After the clay filling is completed, the outer end of the clay filling section 3 is sealed by building a brick masonry 5; the gate valve 41 on the water pipe 4 is closed, and then the water pipe 4 outside the gate valve 41 is densely filled with clay to isolate water, and then the part of the water pipe 4 outside the mine hole is cut off; C30 corrosion-resistant concrete is cast at the opening of the mine 1 to form a concrete plugging section 2, and the water pipe 4 and the gate valve 41 are cast together in the mine 1 to complete the plugging of the wellhead.

[0073] The length of the concrete plugging section 2 should meet the following requirements: L ≥ P*A*K / (C*frb)

[0074] In the formula, L: length of the concrete sealing section of the water wellhead (M), P: water pressure near the water wellhead (Kpa), A: cross-sectional area of ​​the water wellhead (㎡), K: safety factor, C: cross-sectional circumference of the water wellhead (M), Frb: characteristic value of the bond strength between the cave wall and concrete (Kpa).

[0075] The water pressure near the wellhead of No. 3 well is 1000KPa, and the cross-sectional area of ​​the wellhead is 2*2=4m 2 , the circumference of the section of the wellhead is 2*4=8m. Considering that the wellhead is a strongly weathered bedrock, the characteristic value of the bond strength between the wall and the concrete is 180 Kpa, and the safety factor is 2; when the above formula is used for calculation, the length of the concrete plugging section 2 of the 3# well is L=5.6m. That is, the length of the concrete plugging section 2 is not less than 5.6m.

[0076] The brickwork 5 built in step 4) has a compressive strength of not less than M10 and a thickness of not less than 0.24 m. The clay filling in the clay filling section 3 can be kept dense and stable, and the brickwork 5 is closely attached to the surrounding walls of the cave to prevent seepage.

[0077] In the step 6), before clay filling, the clay needs to be fully mixed after adding water, and the clay is manually filled in layers with a layer thickness of no more than 20CM. The clay is compacted during filling with a compaction coefficient of no less than 0.85 to ensure the water-blocking effect of the clay filling section 3 formed by the clay.

[0078] The water pipe 4 is arranged at a position higher than the silted soil in the mine 1. The diameter of the water pipe 4 is greater than 75 mm, and a PPR pipe can be used.

[0079] Example 2

[0080] like Figure 2As shown in the figure, the mine plugging structure of No. 4 shaft of Yongqing Coal Mine in Shuanghui Town, Wangcang County, Sichuan Province, adopts the construction technology of roughening and grooving the cave wall, brickwork, temporary water diversion, clay filling, and concrete plugging of the wellhead to form a mine plugging structure to plug the water gushing from Mine No. 1. The specific implementation includes the following construction steps:

[0081] 1) Wellhead cleaning: clean up the silted soil in the wellhead section 1 and review the geological conditions of the wellhead section 1;

[0082] 2) Roughening and grooving of the tunnel wall: roughening the weathered layer of the tunnel wall in the mine 1 to the fresh rock layer; setting the position and length of the clay filling section 3 in the mine, and setting interval grooves 21 around the set clay filling section 3 tunnel wall, and performing interval grooves 21 around the set clay filling section 3 tunnel wall; this can ensure that the filled clay is completely combined with the tunnel wall to prevent water seepage;

[0083] The length of clay filling section 3 should meet the following requirements: L1 ≥ P*K S *K / (A*γ*Q)

[0084] Where, L1: length of clay filling section 3 (m), P: water pressure near the wellhead (Kpa), A: cross-sectional area of ​​the wellhead (㎡), K S : Clay permeability coefficient (cm / s), γ: Clay density (t / m 3 ), Q: water inflow from wellhead (m 3 / d), K: safety factor;

[0085] The water pressure near the wellhead of No. 4 well is 1000KPa, and the cross-sectional area of ​​the wellhead is 1.8*2=3.6m 2 , the permeability coefficient of clay is 5*10 -5 cm / s, clay weight is 1.64t / m 3 , the water inflow at the wellhead is 520m 3 / d, the safety factor is 2, and the length of the clay filling section 3 of well 4# is L1=3.06m;

[0086] 3) Concrete cushion: The bottom section of Mine 1 is roughened and then a concrete cushion is laid to facilitate the cleaning of water and silt in the construction area;

[0087] 4) Brickwork: Brickwork 5 is set at the inner side of the clay filling section 3 away from the wellhead of the mine 1, and the brickwork 5 is ensured to be in close contact with the wall of the mine 1; the clay filling is ensured to be dense to prevent water seepage;

[0088] 5) Temporary water diversion: During the construction of the brickwork 5, a water diversion pipe 4 is set to divert the water gushing out of the mine 1. The water diversion pipe 4 is located higher than the siltation soil in the mine 1, and a gate valve 41 is set on the water diversion pipe 4; the water diversion pipe 4 runs through the clay filling section 3 and the concrete blocking section 2 to prevent water from accumulating on the construction area and ensure the construction quality. The diameter of the water diversion pipe 4 is greater than 75 mm, and the interface of the water diversion pipe 4 is located higher than the siltation soil in the cave to prevent silt from blocking the water diversion pipe 4;

[0089] 6) Clay filling: Fill the clay filling section 3 where the wall roughening and groove carving in step 3) have been completed in the mine with clay;

[0090] 7) Concrete plugging of the wellhead: After the clay filling is completed, the outer end of the clay filling section 3 is closed by building a brick masonry 5; the gate valve 41 on the water pipe 4 is closed, and then the water pipe 4 outside the gate valve 41 is densely filled with clay to isolate water, and then the part of the water pipe 4 outside the mine hole is cut off; C30 corrosion-resistant concrete is cast at the opening of the mine 1 to form a concrete plugging section 2, and the water pipe 4 and the gate valve 41 are cast together in the mine 1 to complete the plugging of the wellhead of the mine 1.

[0091] The length of the concrete plugging section 2 should meet the following requirements: L ≥ P*A*K / (C*frb)

[0092] In the formula, L: length of concrete sealing section 2 of the water wellhead (M), P: water pressure near the water wellhead (Kpa), A: cross-sectional area of ​​the water wellhead (㎡), K: safety factor, C: cross-sectional circumference of the water wellhead (M), Frb: characteristic value of the bond strength between the cave wall and concrete (Kpa).

[0093] The water pressure near the wellhead of well 4# is 1000KPa, and the cross-sectional area of ​​the wellhead is 1.8*2=3.6m 2 The circumference of the cross-section of the water well mouth is (1.8+2)*2=7.6m. Considering that the cave mouth is strongly weathered bedrock, the characteristic value of the bond strength between the cave wall and concrete is 180Kpa, and the safety factor is 2. Substitute it into the above formula and calculate, and the length of the concrete sealing section 2 of the 4# well is L=5.3m.

[0094] The brickwork 5 built in step 4) has a compressive strength of not less than M10 and a thickness of not less than 0.24 m, which can keep the clay filling in the clay filling section 3 dense and stable, and the brickwork 5 is in close contact with the surrounding walls of the cave to prevent seepage.

[0095] In the step 6), before clay filling, the clay needs to be fully mixed after adding water, and the clay is filled manually in layers with a layer thickness of no more than 20CM. The clay is compacted during filling with a compaction coefficient of no less than 0.85 to ensure the water-blocking effect of the clay filling section 3.

[0096] Example 3

[0097] like Figure 3 As shown in the figure, the mine plugging structure of No. 5 shaft of Yongqing Coal Mine in Shuanghui Town, Wangcang County, Sichuan Province, adopts the construction technology of roughening and grooving the cave wall, brickwork, temporary water diversion, clay filling, and concrete plugging of the wellhead to plug the water gushing from Mine 1. The specific implementation process includes the following construction steps:

[0098] 1) Wellhead cleaning: clean up the silted soil in the wellhead section 1 and review the geological conditions of the wellhead section 1;

[0099] 2) Roughening and grooving of the tunnel wall: roughening the weathered layer of the tunnel wall in the mine 1 to the fresh rock layer; setting the position and length of the clay filling section 3 in the mine, and setting interval grooves 21 around the set clay filling section 3 tunnel wall, and performing interval grooves 21 around the set clay filling section 3 tunnel wall; this can ensure that the filled clay is completely combined with the tunnel wall to prevent water seepage;

[0100] The length of clay filling section 3 should meet the following requirements: L1 ≥ P*K S *K / (A*γ*Q)

[0101] Where, L1: length of clay filling section 3 (m), P: water pressure near the wellhead (Kpa), A: cross-sectional area of ​​the wellhead (㎡), K S : Clay permeability coefficient (cm / s), γ: Clay density (t / m 3 ), Q: water inflow from wellhead (m 3 / d), K: safety factor;

[0102] The water pressure near the wellhead of No. 5 well is 1000KPa, and the cross-sectional area of ​​the wellhead is 1.8*1.6=2.88m 2 , the permeability coefficient of clay is 5*10 -5 cm / s, clay weight is 1.64t / m 3 , the water inflow at the wellhead is 600m 3 / d, with a safety factor of 2, and the length of the clay filling section 3 of well 5# is L1=2.83m;

[0103] 3) Concrete cushion: The bottom section of Mine 1 is roughened and then a concrete cushion is laid to facilitate the cleaning of water and silt in the construction area;

[0104] 4) Brickwork: Brickwork 5 is set at the inner side of the clay filling section 3 away from the wellhead of the mine 1, and the brickwork 5 is ensured to be in close contact with the wall of the mine 1; the clay filling is ensured to be dense to prevent water seepage;

[0105] 5) Temporary water diversion: During the construction of the brickwork 5, a water diversion pipe 4 is set to divert the water gushing out of the mine 1. The water diversion pipe 4 is located higher than the siltation soil in the mine 1, and a gate valve 41 is set on the water diversion pipe 4; the water diversion pipe 4 runs through the clay filling section 3 and the concrete blocking section 2 to prevent water from accumulating on the construction area and ensure the construction quality. The diameter of the water diversion pipe 4 is greater than 75 mm, and a PPR pipe can be used. The interface of the water diversion pipe 4 is located higher than the siltation soil in the cave;

[0106] 6) Clay filling: Fill the clay filling section 3 where the wall roughening and groove carving in step 3) have been completed in the mine with clay;

[0107] 7) Concrete plugging of the wellhead: After the clay filling is completed, the outer end of the clay filling section 3 is sealed by building a brick masonry 5; the gate valve 41 on the water pipe 4 is closed, and then the water pipe 4 outside the gate valve 41 is densely filled with clay to isolate water, and then the part of the water pipe 4 outside the mine hole is cut off; C30 corrosion-resistant concrete is cast at the opening of the mine 1 to form a concrete plugging section 2, and the water pipe 4 and the gate valve 41 are cast together in the mine 1 to complete the plugging of the wellhead.

[0108] The length of the concrete plugging section 2 should meet the following requirements: L ≥ P*A*K / (C*frb)

[0109] In the formula, L: length of concrete sealing section 2 of the water wellhead (M), P: water pressure near the water wellhead (Kpa), A: cross-sectional area of ​​the water wellhead (㎡), K: safety factor, C: cross-sectional circumference of the water wellhead (M), Frb: characteristic value of the bond strength between the cave wall and concrete (Kpa).

[0110] The water pressure near the wellhead of No. 5 well is 1000KPa, and the cross-sectional area of ​​the wellhead is 1.8*1.6=2.88m 2 The circumference of the cross-section of the water well mouth is (1.8+1.6)*2=6.8m. Considering that the cave mouth is strongly weathered bedrock, the characteristic value of the bond strength between the cave wall and concrete is 180Kpa, and the safety factor is 2. Substitute it into the above formula and calculate, and the length of the concrete sealing section 2 of the 5# well is L=4.7m.

[0111] The brickwork 5 constructed in step 4) has a compressive strength of not less than M10 and a thickness of not less than 0.24 m.

[0112] In the step 6), before clay filling, the clay needs to be fully mixed after adding water, and the clay is filled manually in layers with a layer thickness of no more than 20CM. The clay is compacted during filling with a compaction coefficient of no less than 0.85 to ensure the water-blocking effect of the clay filling section 3.

[0113] After the above-mentioned plugging was implemented in the mines of the above three embodiments, after a long period of actual observation, good plugging effects have been achieved.

[0114] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not limitations on the implementation methods of the present invention. For ordinary technicians in the relevant field, other different forms of changes or modifications can be made based on the above description. It is impossible to list all the implementation methods here. All obvious changes or modifications derived from the technical solution of the present invention are still within the protection scope of the present invention.

Claims

1. A mine plugging method, characterized in that: The mine is sealed by roughening and grooving the cave wall, brickwork, temporary water diversion, clay filling and concrete plugging of the wellhead, including the following steps: 1) Wellhead cleaning: clean up the silted soil at the wellhead section and review the geological conditions of the wellhead section; 2) Roughening and grooving of the tunnel wall: roughening the weathered layer of the tunnel wall in the mine until it reaches the fresh rock layer; setting the position and length of the clay filling section in the mine, and making interval grooves around the tunnel wall of the set clay filling section; 3) Concrete cushion: Lay a concrete cushion on the working surface at the bottom of the mine hole; 4) Brickwork: Brickwork is set up on the inner side of the clay filling section away from the wellhead, and ensure that the brickwork is in close contact with the mine wall; 5) Temporary water diversion: During the brickwork construction, a water diversion pipe is set up to divert the water gushing out of the mine. The position of the water diversion pipe is higher than the siltation soil in the mine, and a gate valve is set on the water diversion pipe; 6) Clay filling: Fill the clay filling section in the mine where the roughening and groove carving of the cave wall in step 2) have been completed; 7) Concrete plugging of the wellhead: After the clay filling is completed, the outer end of the clay filling section is closed by building brick masonry; the gate valve on the water pipe is closed, and then the water pipe outside the gate valve is densely filled with clay to isolate water, and then the part of the water pipe outside the mine hole is cut off; C30 corrosion-resistant concrete is poured at the mine hole to form a concrete plugging section, and the water pipe and gate valve are poured together in the mine to complete the plugging of the wellhead.

2. A mine plugging method according to claim 1, characterized in that: The length of the clay filling section in step 2) should meet the following requirements: L1≥P*K s *K / (A*γ*Q) Where, L1: length of clay filling section (m), P: water pressure near the wellhead (kPa), A: cross-sectional area of ​​the wellhead (m 2 ), K s : Clay permeability coefficient (cm / s), γ: Clay density (t / m 3 ), Q: water inflow from wellhead (m 3 / d), K: safety factor.

3. A mine plugging method according to claim 1, characterized in that: In the step 7), the wellhead is sealed with concrete, and the length of the concrete sealing section should meet the following requirements: L ≥ P*A*K / (C*frb) In the formula, L: length of the concrete sealing section of the water wellhead (m), P: water pressure near the water wellhead (kPa), A: cross-sectional area of ​​the water wellhead (m2), K: safety factor, C: circumference of the cross-sectional area of ​​the water wellhead (m), frb: characteristic value of the bond strength between the cave wall and concrete (kPa).

4. A mine plugging method according to any one of claims 1 to 3, characterized in that: The compressive strength of the brick masonry in step 4) is not less than M10 and the thickness is not less than 0.24m.

5. A mine plugging method according to any one of claims 1 to 3, characterized in that: In the step 6), before clay filling, the clay needs to be fully mixed after adding water, and the clay is filled manually in layers, with a layer thickness of no more than 20 cm. The clay is compacted during filling, and the compaction coefficient is no less than 0.

85.

6. A mine plugging structure according to the method of claim 1, comprising a mine (1) and a concrete plugging section (2) arranged in the mine (1), characterized in that: The invention also comprises a clay filling section (3) and a water conduit (4) arranged in the mine (1); the clay filling section (3) is arranged in front of the concrete blocking section (2); the clay filling section (3) is filled with clay; brickwork (5) for sealing is provided at both ends of the clay filling section (3); in the clay filling section (3), the roughened inner wall of the mine (1) is provided with spaced grooves (21); the water conduit (4) passes through the clay filling section (3) and the concrete blocking section (2); and a gate valve (41) is provided on the water conduit (4).

7. A mine sealing structure according to claim 6, characterized in that: The inner wall of the mine shaft (1) of the concrete plugging section (2) is roughened.

8. A mine sealing structure according to claim 6, characterized in that: A concrete cushion layer is provided on the ground surface of the mine (1) within the clay filling section (3) and the concrete blocking section (2).

9. A mine sealing structure according to any one of claims 6 to 8, characterized in that: The water pipe (4) is arranged at a position higher than the silted soil in the mine (1); the water pipe (4) is a PPR pipe with a diameter greater than 75 mm.

10. A mine plugging structure according to any one of claims 6 to 8, characterized in that: The compaction coefficient of the clay in the clay filling section (3) is not less than 0.85.

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