A construction and treatment method for hydrophobic drilling of water inrush points in inclined mine shafts

Abstract

The present invention discloses a construction and treatment method for a water drainage borehole at a water inrush point in an inclined shaft, which relates to the technical field of water drainage borehole construction for water inrush points in coalfield mines and includes the following steps: a step of determining the types of construction parameters, a step of determining the implementation of parameters, and a step of grouting and curing for the inclined shaft. The present invention adopts group borehole pumping and water drainage pressure reduction to first lower the water level of the gravel aquifer around the water inrush point. When the water inflow is very small, grouting and plugging are carried out from the inverted arch in the inclined shaft. The operation is easy and the plugging effect is good.

Description

Technical Field

[0001] The present invention relates to the technical field of construction of drainage boreholes at water inrush points in coal mine shafts, and particularly to a construction and treatment method for drainage boreholes at water inrush points in inclined shafts. Background Art

[0002] Generally, vertical shafts and inclined shafts are used in a mixed way for mine development. Among them, the vertical shaft is the main shaft, responsible for coal hoisting, and the auxiliary inclined shaft is mainly responsible for auxiliary hoisting and serves as a safety passage, with a slope of about -28°. The shaft is located in a gravel aquifer. During heavy rainfall in the rainy season, the groundwater level rises, and the water in the underground aquifer, fault fissure water, and old goaf water gather and penetrate into the auxiliary inclined shaft through various channels and rock fissures. When the shaft wall of the inclined shaft ruptures under the extrusion of the gravel aquifer, it becomes a water inrush point where a large amount of underground aquifer water surges into the shaft, and the water volume in the mine increases sharply in a short time. Long-term shaft water inrush will cause the mud and sand in the shaft wall gravel to be washed away by the inrush water, and the water inrush channel gradually enlarges. When the water entering the auxiliary inclined shaft exceeds the normal drainage capacity, a flood will occur. This not only seriously damages the normal transportation and production of the auxiliary inclined shaft but also threatens the lives and property safety of the people.

[0003] To solve the problem of mine plugging, currently, the commonly used methods are dynamic water grouting and static water grouting. However, for the treatment of roadway water inrush with a large water output, it is difficult to use the dynamic water grouting method for treatment, and there is no precedent at home and abroad; if the static water grouting method is used, it can only wait until the roadway is flooded, which causes huge losses to the mine. Since once a large water inrush point occurs in the auxiliary inclined shaft, its water output is huge, and there is currently no economical and effective rapid construction and treatment method.

[0004] Therefore, proposing a construction and treatment method for drainage boreholes at water inrush points in inclined shafts to solve the difficulties existing in the prior art is an urgent problem for those skilled in the art. Summary of the Invention

[0005] In view of this, the present invention provides a construction and treatment method for drainage boreholes at water inrush points in inclined shafts, which realizes the rapid dewatering of large water inrush points in inclined shafts and repairs the damaged inclined shafts, completely solves the problems of water inrush and seepage in inclined shafts, and restores the normal production of the mine.

[0006] To achieve the above object, the present invention adopts the following technical solutions:

[0007] A construction and treatment method for drainage boreholes at water inrush points in inclined shafts includes the following steps:

[0008] S101. Step of determining the types of construction parameters: Based on the water inrush point in the inclined shaft, determine the types of construction parameters for the drainage boreholes.

[0009] S201. Step of determining the implementation of parameters: Determine the implementation methods of each construction parameter.

[0010] S301. Inclined shaft grouting maintenance steps: Drain the gravel aquifer where the inclined shaft is located to reduce the water volume at the water outlet point of the auxiliary inclined shaft. When the water volume at the water gushing point of the auxiliary inclined shaft drops below the first standard value, construct an inverted arch near the water gushing point of the auxiliary inclined shaft and carry out post-grouting behind the shaft wall, so as to reduce the water gushing volume at the water gushing point of the auxiliary inclined shaft below the second standard value and complete the treatment.

[0011] Optionally, the types of construction parameters in S101 include: the layout range and spacing of dewatering boreholes; the number of boreholes; the size and structure of boreholes.

[0012] Optionally, the specific implementation content of the layout range and spacing of dewatering boreholes in S201 is as follows:

[0013] Taking the water inrush point as the center, drill holes starting from the position L 1 m away from the inclined shaft on both sides of the shaft. The dewatering boreholes are arranged at intervals of L 2 m and a row of dewatering holes are drilled in the direction of the bottom of the well, which is the first row of dewatering holes.

[0014] Optionally, according to the dewatering speed and effect in S201, a row of dewatering holes is added at L 3 m inside the first row of dewatering holes. The hole spacing is the same as or similar to that of the first row of dewatering holes, but is arranged in a staggered manner with the first row of dewatering holes, which is the second row of dewatering holes.

[0015] Optionally, the specific implementation content of the size and structure of dewatering boreholes in S201 is as follows:

[0016] The dewatering boreholes are advanced without core from the ground downwards, and the hole diameter becomes smaller from top to bottom. The depth of the dewatering boreholes is based on reaching the bedrock.

[0017] Optionally, in S201, three-stage boreholes and three-stage casing pipes are adopted. The upper two sections of the casing pipes are solid pipes, and the bottommost section is a grid pipe.

[0018] Optionally, the specific implementation content of the number of dewatering boreholes in S201 is as follows:

[0019] The number of dewatering boreholes is determined by calculation using the large well method according to the water gushing volume of the auxiliary inclined shaft. The specific process is as follows:

[0020] First, arrange multiple dewatering boreholes, and then increase the dewatering boreholes according to the dewatering effect for joint dewatering. When the water level of the gravel aquifer where the inclined shaft is located is reduced and the water gushing volume at the water inrush point of the auxiliary inclined shaft is decreased, and when the water gushing volume of the auxiliary inclined shaft drops below the first standard value, stop increasing the dewatering boreholes.

[0021] Optionally, the specific implementation content of the inverted arch construction of the inclined shaft in S301 is as follows:

[0022] When the water inflow of the auxiliary inclined shaft drops below the first standard value, while all the dewatering boreholes are dewatering together, reinforced concrete inverted arches are constructed from the inclined shaft within the vicinity of the water gushing point, and grouting pipes are embedded within a vertical range of L 4 m above and below the water gushing point.

[0023] Optionally, after the construction of the inverted arch is completed and cured for t days, the embedded grouting pipes are subjected to post-grouting behind the shaft wall, so as to reduce the water inflow of the water gushing point of the auxiliary inclined shaft below the second standard value.

[0024] As can be seen from the above technical solutions, compared with the prior art, the present invention provides a method for constructing and treating dewatering boreholes at the water inrush point of an inclined shaft: adopting group hole pumping and dewatering pressure reduction to first lower the water level of the gravel aquifer around the water inrush point. When the water output is very small, grouting and plugging are carried out from the inverted arch within the inclined shaft. The operation is easy and the plugging effect is good. Description of the Drawings

[0025] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only the embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on the provided drawings.

[0026] Figure 1 It is a flow chart of a method for constructing and treating dewatering boreholes at the water inrush point of an inclined shaft provided by the present invention;

[0027] Figure 2 It is an arrangement diagram of dewatering boreholes provided for a specific embodiment of the present invention;

[0028] Among them: 1 - dewatering borehole, 2 - water inrush point. Detailed Embodiment

[0029] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0030] Referring to Figure 1 as shown, the present invention discloses a method for constructing and treating dewatering boreholes at the water inrush point of an inclined shaft, including the following steps:

[0031] S101. Step of determining the types of construction parameters: Based on the water inrush point of the inclined shaft, determine the types of construction parameters for the dewatering boreholes;

[0032] S201. Parameter implementation determination step: Determine the implementation methods of each construction parameter;

[0033] S301. Inclined shaft grouting maintenance step: Drain the gravel aquifer where the inclined shaft is located to reduce the water volume at the water outlet point of the auxiliary inclined shaft. When the water volume at the water gushing point of the auxiliary inclined shaft drops below the first standard value, construct an inverted arch near the water gushing point of the auxiliary inclined shaft and perform post-grouting behind the shaft wall, so as to reduce the water gushing volume at the water gushing point of the auxiliary inclined shaft below the second standard value and complete the treatment.

[0034] Furthermore, the types of construction parameters in S101 include: the layout range and spacing of dewatering boreholes; the number of boreholes; the size and structure of boreholes.

[0035] Even further, the specific implementation content of the layout range and spacing of dewatering boreholes in S201 is:

[0036] Taking the water inrush point as the center, drill holes starting from the position L 1 m away from the inclined shaft on both sides of the shaft. The dewatering boreholes are arranged at intervals of L 2 m and drill a row of dewatering holes in the direction of the bottom of the shaft, which is the first row of dewatering holes.

[0037] Specifically, L 1 m can be 15 ± 1 m, and L 2 m can be 10 ± 1 m.

[0038] Furthermore, according to the dewatering speed and effect in S201, add a row of dewatering holes at L 3 m inside the first row of dewatering holes. The hole spacing of this row is the same as or similar to that of the first row of dewatering holes, but it is arranged in a staggered manner with the first row of dewatering holes, which is the second row of dewatering holes.

[0039] Specifically, L 3 m can be 3 - 5 m.

[0040] Furthermore, the specific implementation content of the size and structure of dewatering boreholes in S201 is:

[0041] The dewatering boreholes are advanced without core from the ground downwards, and the hole diameter becomes smaller from top to bottom. The depth of the dewatering boreholes is based on reaching the bedrock.

[0042] Furthermore, in S201, three - stage boreholes and three - stage casing pipes are adopted. The upper two sections of the casing pipes are solid pipes, and the bottommost section is a screen pipe.

[0043] Even further, the hole diameter structure is flexibly controlled according to the formation and actual construction. If the construction is easy, two - stage hole diameters and two - stage casing pipes can also be adopted, with the upper section being a solid pipe and the lower section being a screen pipe.

[0044] Furthermore, the specific implementation content of the number of dewatering boreholes in S201 is:

[0045] The number of hydrophobic boreholes is determined by the large well method according to the water inflow of the auxiliary inclined shaft. The specific process is as follows:

[0046] First, arrange multiple hydrophobic boreholes, and then increase the number of hydrophobic boreholes according to the hydrophobic effect for combined hydrophobic drainage. When the water level of the gravel aquifer where the inclined shaft is located is lowered and the water inflow at the water inrush point of the auxiliary inclined shaft is reduced, when the water inflow of the auxiliary inclined shaft drops below the first standard value, stop increasing the hydrophobic boreholes.

[0047] Specifically, the first standard value can be 50 m 3 / h.

[0048] Furthermore, the specific content of the invert construction of the inclined shaft in S301 is as follows:

[0049] When the water inflow of the auxiliary inclined shaft drops below the first standard value, while all the hydrophobic boreholes are jointly draining water, construct a reinforced concrete invert from the inside of the inclined shaft near the water inrush point, and embed grouting pipes vertically within a range of L 4 m above and below the water inrush point.

[0050] Specifically, L 4 m can be 65 m.

[0051] Furthermore, after the invert construction is completed and cured for t days, perform post-grouting behind the shaft wall for the embedded grouting pipes, so as to reduce the water inflow at the water inrush point of the auxiliary inclined shaft below the second standard value.

[0052] Specifically, t days can be 26 - 30 days, and the second standard value can be 6 m 3 / h.

[0053] Furthermore, from the ground downwards, the boreholes are divided into 0 - 30 m, 30 - 60 m, and 60 - 85 m; the borehole diameters are φ500 mm, φ420 mm, and φ355 mm in sequence, and the casing diameters are φ426 mm, φ377 mm, and φ325 mm in sequence;

[0054] The depth of the hydrophobic boreholes is based on reaching the bedrock (about 85 m);

[0055] After the water volume at the water inrush point of the auxiliary inclined shaft drops below 50 m 3 / h, construct a reinforced concrete invert within a range of 30 m above the water inrush point to 35 m below the water inrush point, a total of 65 m, and embed φ60 mm grouting pipes.

[0056] The present invention takes the water inrush point as the center, and on both sides of the inclined shaft, 2 to 3 rows of drainage boreholes are arranged in the direction of the well depth. The longitudinal spacing of the boreholes is 10 ± 1 m, and the transverse spacing is 3 to 5 m, arranged in a staggered manner. The boreholes are advanced without core from the ground downwards, using three-stage boreholes and three-stage casing pipes. The hole diameters decrease from large to small from top to bottom. The depth of the boreholes is based on reaching the bedrock. The upper two sections of the casing pipes are solid pipes, and the lower section is a grid pipe; the drainage boreholes are arranged in rows and staggered, and jointly drain water, which can quickly lower the water level of the gravel aquifer and achieve the purpose of reducing the water inflow of the inclined shaft; the number of boreholes is calculated and determined by the large well method according to the water inflow. A number of drainage boreholes are arranged in advance, and several boreholes are added according to the drainage effect, which can avoid unnecessary waste; by using group borehole pumping and drainage pressure reduction, the water level of the gravel aquifer around the water inrush point is reduced. When the water output is 50 m 3 / h, the invert construction is carried out from the inside of the inclined shaft, and the grouting pipes are embedded and maintained for one month, and then grouted and sealed. The operation is easy and the sealing effect is good.

[0057] In a specific embodiment, taking the water inrush of a certain auxiliary inclined shaft in a coal mine in Henan as an example, referring to Figure 2 as shown, the rapid construction and treatment method of drainage boreholes for extremely large water inrush points in coal mine inclined shafts provided by the present invention is further described.

[0058] Due to the large-scale atmospheric precipitation in the whole province infiltrating into the shaft along the Quaternary surface soil layer, the water inflow of the auxiliary inclined shaft continues to increase. The auxiliary inclined shaft shaft bursts and water inrushes at 124 m (water inrush point 2). The mud and sand in the Quaternary gravel are washed away by the water inrush, and the water inrush channel gradually increases. Due to sufficient recharge water source, the water inflow is getting larger and larger. After more than twenty days, the water inflow continues to increase and stabilizes at 2300 m 3 / h. The long-term water inrush in the shaft poses a serious threat to the transportation of the auxiliary inclined shaft and the safety of the mine. Therefore, around the water inrush point of the auxiliary inclined shaft, 18 drainage boreholes 1 are arranged in advance on the ground on both sides of the auxiliary inclined shaft shaft, and then 6 drainage boreholes 1 are added. A total of 24 drainage boreholes 1 are arranged to jointly drain water. When the water volume of the water inrush point of the auxiliary inclined shaft drops below 50 m 3 / h, a reinforced concrete invert is constructed within a range of 30 m above the water inrush point to 35 m below the water inrush point, a total of 65 m, and φ60 mm grouting pipes are embedded. After the invert construction is completed and maintained for 28 days, shaft wall back grouting is carried out within a range of 30 m above the water inrush point of the auxiliary inclined shaft to 35 m below the water inrush point, a total of 65 m, so as to reduce the water volume of the water inrush point below 6 m 3 / h. Table 1 shows the coordinates and depths of the drainage boreholes:

[0059] Table 1 Coordinates and Depths of Drainage Boreholes

[0060]

[0061] This project started on October 12, 2021 and ended on December 29, 2021, lasting for 79 days. A total of 24 drainage boreholes were constructed, and the borehole depth, final hole horizon, hole diameter structure, and casing length all met the design requirements.

[0062] Engineering effect: A total of 24 drainage boreholes were constructed in this project, with a total footage of 2140m. Through pumping, there is no longer water gushing out within 20m above and below the 124m (at the second refuge chamber) of the auxiliary inclined shaft shaft, achieving the expected effect, relieving the pressure of underground drainage, and creating good construction conditions for shaft repair and subsequent treatment.

[0063] The above description of the disclosed embodiments is presented in a progressive manner so that those skilled in the art can implement or use the present invention. Various modifications to these embodiments will be obvious to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to these embodiments shown herein, but rather to the broadest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for constructing and treating a water drainage borehole at a water inrush point in an inclined shaft, characterized in that, it includes the following steps: S101. Step of determining the types of construction parameters: Based on the water inrush point in the inclined shaft, determine the types of construction parameters for the water drainage borehole; The types of construction parameters in S101 include: the layout range and spacing of the water drainage boreholes, the number of boreholes, the borehole size and structure; S201. Step of determining the implementation of parameters: Determine the implementation methods of each construction parameter; S301. Step of grouting and curing the inclined shaft: Drain the gravel aquifer where the inclined shaft is located to reduce the water volume at the water outlet point of the auxiliary inclined shaft. When the water volume at the water inrush point of the auxiliary inclined shaft drops below the first standard value, construct an inverted arch near the water inrush point of the auxiliary inclined shaft and perform post-grouting behind the shaft wall, so as to reduce the water inrush volume at the water inrush point of the auxiliary inclined shaft below the second standard value and complete the treatment; The specific content of the inverted arch construction of the inclined shaft in S301 is: When the water inrush volume of the auxiliary inclined shaft drops below the first standard value, while all the water drainage boreholes are draining water together, construct a reinforced concrete inverted arch from inside the inclined shaft near the water inrush point, and embed grouting pipes within a vertical range of L4 m above and below the water inrush point; After the inverted arch construction is completed and cured for t days, perform post-grouting behind the shaft wall on the embedded grouting pipes, so as to reduce the water inrush volume at the water inrush point of the auxiliary inclined shaft below the second standard value.

2. A method for constructing and treating a water drainage borehole at a water inrush point in an inclined shaft according to claim 1, characterized in that, The specific content of the implementation of the layout range and spacing of the water drainage boreholes in S201 is: Taking the water inrush point as the center, drill holes starting from a position L1 m away from the inclined shaft on both sides of the shaft. The water drainage boreholes are arranged at an interval of L2 m, and a row of water drainage holes are drilled in the direction of the bottom of the shaft, which is the first row of water drainage holes.

3. A method for constructing and treating a water drainage borehole at a water inrush point in an inclined shaft according to claim 2, characterized in that, In S201, according to the water drainage speed and effect, add a row of water drainage holes at a distance of L3 m inside the first row of water drainage holes. The hole spacing of this row is the same as or similar to that of the first row of water drainage holes, but is arranged in a staggered manner with the first row of water drainage holes, which is the second row of water drainage holes.

4. A method for constructing and treating a water drainage borehole at a water inrush point in an inclined shaft according to claim 1, characterized in that, The specific content of the implementation of the borehole size and structure of the water drainage borehole in S201 is: The water drainage borehole is advanced without a core from the ground downwards, and the borehole diameter gradually decreases from top to bottom. The depth of the water drainage borehole is based on reaching the bedrock.

5. A method for constructing and treating a water drainage borehole at a water inrush point in an inclined shaft according to claim 4, characterized in that, In S201, three-stage boreholes and three-stage casings are adopted. The upper two sections of the casings are solid pipes, and the bottommost section is a screen pipe.

6. A method for constructing and treating a water drainage borehole at a water inrush point in an inclined shaft according to claim 1, characterized in that, The specific content of the implementation of the number of water drainage boreholes in S201 is: The number of water drainage boreholes is set and determined by calculating using the large well method according to the water inrush volume of the auxiliary inclined shaft. The specific process is: Arrange multiple dewatering boreholes in advance, and then increase the dewatering boreholes according to the dewatering effect for combined dewatering. When the water level of the gravel aquifer where the inclined shaft is located is lowered and the water inflow at the water inrush point of the auxiliary inclined shaft is reduced, stop increasing the dewatering boreholes when the water inflow of the auxiliary inclined shaft drops below the first standard value.

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