Coal mine inclined shaft wellbore water treatment method

Abstract

The application discloses a coal mine inclined shaft wellbore water treatment method, the spatial position of the coal mine inclined shaft wellbore water treatment is determined through theoretical calculation, a directional drilling, segmentation, sequence, advancing type grouting method parallel to the inclined shaft wellbore is adopted to form a ring curtain body around the inclined shaft wellbore, the directional drainage mode increases the slurry diffusion range and diffusion efficiency, and reduces the water inflow of the strong water-rich and strong recharge loose layer coal mine inclined shaft wellbore. The application constructs a ring space curtain water interception system of the coal mine inclined shaft wellbore, realizes a strong water-rich and strong recharge stratum ring space omnidirectional water blocking coal mine inclined shaft wellbore treatment method, is suitable for both the strong water-rich loose layer and the rock stratum with developed pores and fissures, solves the problem that the existing inclined shaft treatment method cannot simultaneously satisfy the loose layer and the rock stratum, and greatly improves the strong water-rich and strong recharge stratum inclined shaft wellbore leakage water treatment level and treatment effect.

Description

Technical Field

[0001] This invention belongs to the field of mine water hazard prevention and shaft reinforcement technology, and relates to a method for treating water in inclined shafts of coal mines. Background Technology

[0002] The development of inclined shafts involves traversing aquifers such as water-rich loose layers, weathered bedrock, and porous, fractured bedrock. Construction involves large volumes of water and presents significant challenges. Furthermore, after the shaft is completed, the water level in the loose layers and bedrock outside the shaft continuously rises. Due to factors such as joint gaps in the shaft shaft, water intake holes, masonry cracks, and construction defects, the inclined shaft is highly susceptible to water leakage. Prolonged water leakage will lead to water inrush and sand carrying, increasing mine water inflow and drainage costs. It will also deteriorate the working environment inside the shaft, increase environmental pressure, cause corrosion of shaft equipment and facilities, increase maintenance costs, reduce the service life of the inclined shaft and mine equipment, and may even cause shaft rupture, triggering water-related accidents, affecting safe production, and ultimately rendering the shaft unusable.

[0003] To address water leakage in inclined shafts of coal mines, current methods mainly include grouting behind the shaft wall and surface grouting. Grouting behind the shaft wall involves drilling holes at regular intervals in the inclined shaft and lowering grouting pipes to inject grout into the loose layer and weathered bedrock layer outside the shaft. However, this method damages the shaft structure, reduces its strength, and increases the risk of leakage. Surface grouting involves drilling vertically or inclined holes to the location of the leakage point on the ground and injecting grout into the loose layer and weathered bedrock layer outside the leakage point to seal it. However, highly water-rich and strongly replenished strata have extremely developed pores, resulting in complex grout diffusion directions and difficult-to-control diffusion ranges. This makes it difficult to completely seal the seepage channels on the outside of the inclined shaft, failing to achieve the desired seepage prevention and plugging effect. Summary of the Invention

[0004] In view of the shortcomings of the existing technology, the purpose of this invention is to provide a method for treating water in inclined shafts of coal mines, which solves the problems of water leakage, sand-carrying water inrush, structural damage, strength reduction, complex diffusion range of grout injected into vertical boreholes on the ground, difficulty in grout injection, and difficulty in sealing seepage channels in the existing technology.

[0005] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0006] A method for treating water in an inclined shaft of a coal mine includes the following steps:

[0007] Step 1: Investigate the engineering geological and hydrogeological conditions of the inclined shaft of a coal mine with strong water-rich and recharged loose strata, delineate the stratification of the surrounding soil and rock layers, and determine the excavation cross-section height of the inclined shaft. The width of the inclined shaft excavation section B is measured, and the mechanical parameters of the surrounding soil and rock mass, cohesion c and internal friction angle φ, are tested. The number n of leakage points in the inclined shaft and the water level of the loose layer around the inclined shaft are monitored. ;

[0008] Step 2: Calculate the theoretical radius of the loosened zone of the surrounding rock in the inclined shaft. ;

[0009] In the formula: R b理 —Theoretical radius of the loosened zone of the surrounding rock in the inclined shaft, in meters;

[0010] —Equivalent radius of the inclined shaft excavation section, in meters. ;

[0011] h 筒 —Height of the inclined shaft excavation section, in meters;

[0012] B—Width of the inclined shaft excavation section, in meters;

[0013] P—Initial in-situ stress of the surrounding rock of the inclined shaft, MPa, P=γH 埋 ;

[0014] γ—Solid weight of the rock mass surrounding the inclined shaft, N / m 3 ;

[0015] H 埋 —Buried depth of inclined shaft, m;

[0016] P1—initial support reaction force of inclined shaft shaft, MPa;

[0017] c—cohesion of the surrounding rock of the inclined shaft, MPa;

[0018] φ—Angle of friction within the surrounding rock of the inclined shaft, °;

[0019] Step 3: Calculate the theoretical radius of the plastic zone of the rock and soil in the inclined shaft. ;

[0020] In the formula: —Equivalent radius of the inclined shaft excavation section, in meters. ;

[0021] —Strain of the surrounding rock in the inclined shaft, MPa ;

[0022] — Inclined shaft support reaction force, MPa;

[0023] c—cohesion of the soil and rock mass surrounding the inclined shaft, MPa;

[0024] φ—Angle of friction within the soil and rock surrounding the inclined shaft, °;

[0025] γ—Unit weight of the overlying rock and soil of the inclined shaft, kN / m 3 ;

[0026] —Vertical distance from the top of the inclined shaft to the ground surface, in meters;

[0027] Step 4: Determine the theoretical radius of the loosened zone of the surrounding rock in the inclined shaft. The boundary range of the pore and fracture development area on the outer side of the wellbore; the theoretical radius of the plastic zone of the soil and rock mass in the inclined wellbore. This refers to the boundary range of the outer boundary region where pores and fractures develop.

[0028] Step 5: Install online monitoring holes for construction water level and water quality on the outside of the inclined shaft, and install a fully automatic monitoring system in the online monitoring holes to monitor the groundwater level, water quality and flow field parameters around the inclined shaft in real time.

[0029] Step 6: In the area where pores and fractures develop on the outside of the inclined shaft, directional boreholes are arranged along the inclination direction of the shaft and parallel to the outer wall of the inclined shaft. The directional boreholes are constructed in a sequential and segmented manner, and a ring-shaped grouting curtain is constructed by grouting.

[0030] Step 7: Monitor the changes in water level and water quality in the inclined shaft before, during and after the treatment by using online water level and water quality monitoring wells; draw groundwater flow field and groundwater chemical field; monitor and evaluate the water treatment effect in the inclined shaft of coal mines in strong water-rich and strongly recharged strata; and ensure the safe operation of the inclined shaft of coal mines in strong water-rich and strongly recharged strata.

[0031] The present invention also includes the following technical features:

[0032] Specifically, there are multiple directional boreholes, which are respectively arranged at the top, sides and bottom of the inclined shaft.

[0033] Specifically, the number m of directional boreholes is determined according to the size of the inclined well shaft. When the radius of the inclined well shaft is 2 to 4, m is 3 to 5, and when the radius of the inclined well shaft is 4 to 7, m is 5 to 6.

[0034] Specifically, the trajectory of the directional drilling is within the boundary between the inclined wellbore and the area where pores and fractures develop on the outer side of the wellbore.

[0035] Specifically, the annular grouting curtain body includes an annular grouting curtain core area and an annular grouting curtain peripheral area; the annular grouting curtain core area is the range from the outer wall of the inclined well to the outer boundary of the pore and fracture development area on the outside of the well, and the annular grouting curtain peripheral area is the range from the outer boundary of the pore and fracture development area on the outside of the well to the outer boundary of the pore and fracture development area.

[0036] Specifically, in step 6, directional drilling is divided into three phases. The first and second phases both use the hole-to-hole construction process. The third phase hole is used as an inspection hole. When grout leakage is found, the third phase hole is used as a grouting hole for grouting and reinforcement.

[0037] In directional drilling and grouting, the length L of each segment is 10~50m, when the formation permeability coefficient K < 10. -2 When the speed is cm / s, L is taken as 50m; when 10 -2 When cm / s ≤ K < 1 cm / s, L is 40 m; when 1 cm / s ≤ K < 5 cm / s, L is 30 m; when 5 cm / s ≤ K < 10 cm / s, L is 20 m; when 10 cm / s ≤ K, L is 10 m.

[0038] Specifically, the directional drilling segmented grouting volume ;

[0039] Where: Q—the volume of grouting in directional drilling segments;

[0040] —Permeability coefficient of the formation surrounding the borehole;

[0041] —Length of directional drilling sections;

[0042] —Grouting pressure at the orifice of the directional borehole;

[0043] —Water pressure at the contact front between the borehole diffusion slurry and water;

[0044] R —Diffusion radius of grouting fluid in directional drilling;

[0045] r —Radius of directional drilling;

[0046] μ —The dynamic viscosity of a liquid.

[0047] Specifically, step 6, which involves constructing directional drilling and building a ring-shaped grouting curtain using a segmented and sequential approach, includes the following steps:

[0048] Step 6.1: Place the directional drilling rig at the wellhead of the inclined shaft. First, construct the first section length L of the first-sequence directional grouting hole and the first section length L of the first-sequence directional pumping hole. Install the grouting pipe and grouting pressure gauge at the wellhead of the first-sequence directional grouting hole. Grout into the first section length L of the first-sequence directional grouting hole through the grouting pipe. At the same time, lower the pump into the first-sequence directional pumping hole. Use the pump to extract water from the formation near the first section length L of the first-sequence directional pumping hole. The grout in the first-sequence directional grouting hole flows around the well shaft to the first-sequence directional pumping hole. When the water extracted from the first-sequence directional pumping hole changes from clear water to turbid grout, stop pumping and close the valve at the wellhead of the first-sequence directional pumping hole. Continue grouting in the first-sequence directional grouting hole until the grouting flow rate q≤15L / min or the grouting pressure≥2MPa. Then, stop grouting and close the gate valve at the wellhead of the first-sequence directional grouting hole.

[0049] Step 6.2: Install a grouting pipe and pressure gauge at the orifice of the first-order directional pumping hole. Inject grout into the borehole of length L of the first-order directional pumping hole through the grouting pipe. The grout in the first-order directional pumping hole diffuses around the perimeter of the inclined shaft, filling the space of the core area and the outer area of ​​the annular grouting curtain. Stop grouting when the grouting flow rate q ≤ 15 L / min or the grouting pressure ≥ 2 MPa, and close the gate valve at the orifice of the first-order directional pumping hole. After 12 hours of curing, repeat steps 6.1 to 6.2 to complete the drilling and grouting of the next section of length L of the first-order directional grouting hole and the first-order directional pumping hole, until the drilling and grouting construction of the treatment section of the first-order directional grouting hole and the first-order directional pumping hole is completed.

[0050] Step 6.3: Construct the first section L of the second-order directional grouting hole and the first section L of the second-order directional pumping hole. Install a grouting pipe and a grouting pressure gauge at the opening of the second-order directional grouting hole. Grout is injected into the borehole of the first section L of the second-order directional grouting hole through the grouting pipe. At the same time, a pump is lowered into the second-order directional pumping hole to pump water out of the borehole from the strata near the first section L of the second-order directional pumping hole. Repeat step 6.3 to complete the drilling and grouting construction of the treatment sections of the second-order directional grouting hole and the second-order directional pumping hole.

[0051] Step 6.4: Drill the first section of the three-stage directional inspection hole with a length of L and conduct a water pressure test. When the permeability is <0.1Lu, it indicates that the treatment effect of this section is good and has the effect of blocking water and preventing seepage. When the permeability is ≥0.1Lu, it indicates that the treatment effect of this section does not meet the standard and has not achieved an effective effect of blocking water and preventing seepage. Grouting reinforcement is required.

[0052] Step 6.5, repeat step 6.4, to complete the drilling of the three-order directional inspection holes, water pressure test, treatment effect evaluation, grouting reinforcement, and form an annular grouting curtain.

[0053] Specifically, in step 6.4, when the water-blocking and seepage prevention effect of the treatment section does not meet the standard, a grouting pipe and a pressure gauge are installed at the orifice of the three-order directional inspection hole to perform three-order grouting reinforcement on the section. The grout enters the three-order directional inspection hole through the grouting pipe to replenish the residual space in the core area and the outer area of ​​the annular grouting curtain.

[0054] Specifically, the horizontal spacing between the online water level and water quality monitoring holes is 80~100m.

[0055] Compared with the prior art, the present invention has the following technical effects:

[0056] (I) The coal mine inclined shaft water treatment method of the present invention can scientifically and reasonably delineate the treatment area, make full use of the space range of the excavation disturbance area and the loosening zone of the surrounding rock of the shaft, and turn the original unfavorable factors to shaft safety into favorable conditions for grouting diffusion, thus ensuring the safety and durability of the inclined shaft water inrush treatment section.

[0057] (II) This invention determines the spatial location for water treatment in inclined coal mine shafts through theoretical calculations. It adopts a directional drilling, segmented, sequential, and forward grouting method parallel to the inclined shaft to form an annular curtain around the shaft. The directional diversion method increases the diffusion range and efficiency of the slurry, reduces the water inflow in the inclined shaft of coal mines with strong water-rich and strongly replenished loose layers, and overcomes the problems of wide slurry diffusion range, difficult slurry injection, and inadequate sealing of pore channels in the existing technology. It solves the problems of water leakage, sand-carrying water inflow, structural damage and destruction, and reduced strength in the shaft.

[0058] (III) This invention constructs a ring-shaped spatial curtain water interception and seepage prevention system for inclined shafts in coal mines, realizing a method for treating inclined shafts in coal mines that blocks water in all directions in the ring space of highly water-rich and highly replenished strata. This invention is applicable to both loose layers with high water content and rock strata with well-developed pores and fractures, solving the problem that existing inclined shaft treatment methods cannot simultaneously meet the needs of loose layers and rock strata, and significantly improving the level and effect of water leakage treatment in inclined shafts of highly water-rich and highly replenished strata. Attached Figure Description

[0059] Figure 1 This is a schematic diagram showing the relationship between the inclined shaft and the surrounding rock and soil of the present invention;

[0060] Figure 2 This is a schematic diagram of the inclined shaft, surrounding rock and soil, and the location of the directional borehole of the present invention;

[0061] Figure 3 This is a front view of the inclined shaft to be treated according to the present invention;

[0062] Figure 4 This is a top view of the inclined shaft to be treated according to the present invention;

[0063] Figure 5 This is a schematic diagram of the construction of the inclined shaft annular curtain sequential directional grouting hole of the present invention;

[0064] Figure 6 This is a schematic diagram of the construction of the inclined shaft annular curtain sequential directional pumping hole of the present invention;

[0065] Figure 7 This is a schematic diagram of the segmented and sequential construction of the inclined shaft annular curtain directional drilling of the present invention;

[0066] Figure 8 This is a schematic diagram of the construction of the inclined shaft annular curtain two-stage directional grouting hole of the present invention;

[0067] Figure 9 This is a schematic diagram of the construction of the inclined shaft annular curtain two-stage directional pumping hole of the present invention;

[0068] Figure 10 This is a schematic diagram of the construction of the inclined shaft annular curtain three-stage directional inspection hole of the present invention;

[0069] Figure 11 This is a front view of the inclined shaft and annular curtain of the present invention;

[0070] Figure 12 This is a cross-sectional view of the inclined shaft and annular curtain of the present invention along line A-A';

[0071] Figure 13 This is a cross-sectional view of the inclined shaft and annular curtain of the present invention, B-B'.

[0072] The meanings of the labels in the diagram are as follows:

[0073] 1. Inclined wellbore; 2. Leakage point; 3. Pore and fracture development area on the outer side of the wellbore; 4. Outer boundary area of ​​pore and fracture development; 5. Directional drilling rig; 6. Directional borehole; 6-1. First-order directional grouting hole; 6-2. First-order directional pumping hole; 6-3. Second-order directional grouting hole; 6-4. Second-order directional pumping hole; 6-5. Third-order directional inspection hole; 7. Annular grouting curtain body; 7-1. Core area of ​​the annular grouting curtain; 7-2. Outer area of ​​the annular grouting curtain; 8. Online water level and water quality monitoring hole. Detailed Implementation

[0074] The following are specific embodiments of the present invention. It should be noted that the present invention is not limited to the following specific embodiments. All equivalent modifications made based on the technical solutions of this application fall within the protection scope of the present invention.

[0075] Example 1:

[0076] This embodiment provides a method for treating water in inclined shafts of coal mines, including the following steps:

[0077] Step 1, as follows Figure 1As shown, the engineering geological and hydrogeological conditions of the inclined shaft 1 of a coal mine with strong water-rich and strongly replenished loose strata were investigated. The stratification of the surrounding soil and rock layers of the inclined shaft 1 was accurately determined, and the vertical height of the excavation section of the inclined shaft 1 was ascertained. The horizontal width B of the excavation section of the inclined shaft 1 is measured. Mechanical parameters such as the cohesion c and internal friction angle φ of the surrounding soil and rock are tested. The number of leakage points 2 in the inclined shaft 1 is n, and the water inflow at leakage point 2 is... The water level in the loose layer around the well is ;

[0078] Step 2: Calculate the theoretical radius of the loosened zone of the surrounding rock in the inclined shaft 1. R b理 :

[0079] ;

[0080] In the formula: R b理 —Theoretical radius of the loosened zone of the surrounding rock in the inclined shaft, in meters;

[0081] —Equivalent radius of the inclined shaft excavation section, in meters. ;

[0082] h 筒 —Height of the inclined shaft excavation section, in meters;

[0083] B—Width of the inclined shaft excavation section, in meters;

[0084] P—Initial in-situ stress of the surrounding rock of the inclined shaft, MPa, P=γH 埋 ;

[0085] γ—Solid weight of the rock mass surrounding the inclined shaft, N / m 3 ;

[0086] H 埋 —Buried depth of inclined shaft, m;

[0087] P1—initial support reaction force of inclined shaft, MPa;

[0088] c—cohesion of the surrounding rock of the inclined shaft, MPa;

[0089] φ—Internal friction angle of the surrounding rock of the inclined shaft, in degrees;

[0090] Step 3: Calculate the theoretical radius of the plastic zone of the soil and rock mass in the inclined shaft 1. :

[0091] ;

[0092] In the formula: —Equivalent radius of the inclined shaft excavation section, in meters. ;

[0093] —Strain of the surrounding rock in the inclined shaft, MPa ;

[0094] — Inclined shaft support reaction force, MPa;

[0095] c—cohesion of the soil and rock mass surrounding the inclined shaft, MPa;

[0096] φ—Angle of friction within the soil and rock surrounding the inclined shaft, °;

[0097] γ—Unit weight of the overlying rock and soil of the inclined shaft, kN / m 3 ;

[0098] —Vertical distance from the top of the inclined shaft to the ground surface, in meters;

[0099] Step 4, as follows Figure 2 As shown, the theoretical radius of the loosened zone of the surrounding rock in the inclined shaft 1 is determined. The boundary range of pore and fracture development zone 3 on the outer side of the wellbore, and the theoretical radius of the plastic zone of the soil and rock mass in the inclined wellbore 1. The boundary range of region 4, the outer boundary region for the development of pores and fractures;

[0100] Step 5, as follows Figure 7 As shown, online monitoring wells 8 for groundwater level and quality are installed on the outside of the inclined shaft 1. The horizontal spacing between the monitoring wells is 80-100m. A fully automatic monitoring system is installed in each monitoring well to monitor the groundwater level, water quality, and flow field parameters around the inclined shaft 1 in real time. The water level on the outside is recorded as... , , … …;

[0101] Step 6, as follows Figure 2 , Figure 3As shown, directional boreholes 6 are arranged along the inclination direction of the wellbore in the pore and fracture development area 3 outside the inclined wellbore, and the directional boreholes 6 are parallel to the outer wall of the inclined wellbore. To improve the grouting effect and water plugging efficiency, the directional boreholes 6 and the annular grouting curtain 7 are constructed in a sequential and segmented manner; m directional boreholes 6 are respectively arranged at the top, sides and bottom of the inclined wellbore 1; the annular grouting curtain 7 includes an annular grouting curtain core area 7-1 and an annular grouting curtain outer perimeter area 7-2. The annular grouting curtain core area 7-1 is the range from the outer wall of the inclined wellbore 1 to the outer boundary of the pore and fracture development area 3 outside the wellbore, and the annular grouting curtain outer perimeter area 7-2 is the range from the outer boundary of the pore and fracture development area 3 outside the wellbore to the outer boundary of the pore and fracture development outer boundary area 4; as Figure 3 and Figure 4 As shown, the trajectory of directional borehole 6 lies within the boundary between the inclined wellbore 1 and the pore and fracture development region 3 on the outer side of the wellbore. The number m of directional boreholes 6 is determined according to the size of the inclined wellbore. When the wellbore radius... The value is 3~5, and the wellbore radius is... Take 5-6 at a time;

[0102] Directional drilling is divided into three phases. Phases one and two employ a head-on drilling technique. Phase three holes serve as inspection holes; when grout leakage is detected, these holes are used for grouting reinforcement. As shown in Formula 1, the grouting volume is positively correlated with the section length L and the formation permeability coefficient K. The smaller the formation permeability coefficient K, the smaller the grouting volume Q; conversely, the longer the section length L, the larger the grouting volume Q. The grouting volume Q is controlled by the section length L and the formation permeability coefficient K. Based on the geological characteristics of the inclined shaft in coal mines, the section length L for each drilling and grouting phase is 10-50m, with the specific length L determined according to the geological conditions. When the formation permeability coefficient K < 10... -2 When the speed is cm / s, L is taken as 50m; when 10 -2 When cm / s ≤ K < 1cm / s, L is 40m; when 1cm / s ≤ K < 5cm / s, L is 30m; when 5cm / s ≤ K < 10cm / s, L is 20m; when 10cm / s ≤ K, L is 10m.

[0103] (1)

[0104] Where: Q—the volume of grouting in the borehole sections;

[0105] —Permeability coefficient of the formation surrounding the borehole;

[0106] —Length of directional drilling sections;

[0107] —Grouting pressure at the orifice of the directional borehole;

[0108] —Water pressure at the contact front between the borehole diffusion slurry and water;

[0109] R —Diffusion radius of grouting fluid in directional drilling;

[0110] r —Radius of directional drilling;

[0111] μ —The dynamic viscosity of the liquid;

[0112] Step 6, which involves constructing the directional drilling 6 and the annular grouting curtain 7 using a sequential and segmented approach, includes the following steps:

[0113] Step 6.1, as follows Figure 4 As shown, a directional drilling rig 5 is installed at the wellhead of the inclined shaft 1. First, the first section L of a sequential directional grouting hole 6-1 and the first section L of a sequential directional pumping hole 6-2 are constructed. A grouting pipe and a grouting pressure gauge are installed at the opening of the sequential directional grouting hole 6-1. Grout is injected into the borehole of the first section L of the sequential directional grouting hole 6-1 through the grouting pipe. Simultaneously, a pump is lowered into the sequential directional pumping hole 6-2. The pump extracts water from the formation near the first section L of the sequential directional pumping hole 6-2. During water extraction from the formation near the first section L of the sequential directional pumping hole 6-2, the water pressure at that location is increased due to the pump's suction. The value is negative, and water from the surrounding strata continuously converges into the pumping section. According to the calculation theory of Formula 1, the diffusion radius R of the grouting fluid in the directional drilling continuously increases towards the first-order directional pumping hole 6-2. The contact front between the grouting fluid and water in the borehole continuously moves forward to the first-order directional pumping hole 6-2. The water pressure at the contact front of the grouting fluid in the borehole... When the value is negative, the grouting Q increases further, increasing the grout diffusion rate and range, such as... Figure 5 As shown, the grout in the first-order directional grouting hole 6-1 around the well flows around the well to the first-order directional pumping hole 6-2. When the water pumped out of the first-order directional pumping hole 6-2 changes from clear water to turbid grout, pumping is stopped and the orifice valve of the first-order directional pumping hole 6-2 is closed. Grouting continues in the first-order directional grouting hole 6-1 until the grouting flow rate q≤15L / min or the grouting pressure≥2MPa. Grouting is then stopped and the orifice gate valve of the first-order directional grouting hole 6-1 is closed.

[0114] Step 6.2: Install a grouting pipe and pressure gauge at the opening of the first-order directional pumping hole 6-2, and inject grout into the borehole of length L of the first-order directional pumping hole 6-2 through the grouting pipe. Figure 6As shown, the grout in the first-order directional pumping hole 6-2 diffuses around the inclined shaft 1, filling the space of the core area 7-1 and the outer area 7-2 of the annular grouting curtain. Grouting is stopped when the grouting flow rate q ≤ 15 L / min or the grouting pressure ≥ 2 MPa, and the gate valve of the first-order directional pumping hole 6-2 is closed.

[0115] Step 6.3, wait 12 hours, if... Figure 7 As shown, repeat steps 6.1 to 6.2 to complete the drilling and grouting of the next section of length L for the first-order directional grouting hole 6-1 and the first-order directional pumping hole 6-2;

[0116] Step 6.4, as follows Figure 7 As shown, repeat steps 6.1 to 6.3 until the drilling and grouting of the treatment section is completed by the first-order directional grouting hole 6-1 and the first-order directional pumping hole 6-2.

[0117] Step 6.5, as follows Figure 8 , Figure 9 As shown, the first section L of the second-order directional grouting hole 6-3 and the first section L of the second-order directional pumping hole 6-4 are constructed. A grouting pipe and a grouting pressure gauge are installed at the opening of the second-order directional grouting hole 6-3. Grout is injected into the borehole of the first section L of the second-order directional grouting hole 6-3 through the grouting pipe. At the same time, a water pump is lowered into the second-order directional pumping hole 6-4. The water pump is used to pump the water in the stratum near the first section L of the second-order directional pumping hole 6-4 out of the borehole. Step 6.5 is repeated to complete the drilling and grouting construction of the first section of the second-order directional grouting hole 6-3 and the treatment section of the second-order directional pumping hole 6-4.

[0118] Step 6.6, as follows Figure 10 As shown, the first section of the directional inspection hole 6-5 of the third construction sequence was drilled for a water pressure test. When the permeability was <0.1Lu, it indicated that the treatment effect of this section was good and had a good water blocking and seepage prevention effect. When the permeability was ≥0.1Lu, it indicated that the treatment effect of this section did not meet the standard and did not achieve an effective water blocking and seepage prevention effect, and grouting reinforcement was required.

[0119] Step 6.7: When the water-blocking and seepage prevention effect of the treatment section length L in step 6.5 is not up to standard, install a grouting pipe and pressure gauge at the opening of the three-order directional inspection hole 6-5, and perform three-order grouting reinforcement on the section. The grout enters the three-order directional inspection hole 6-5 through the grouting pipe to fill the residual space of the core area 7-1 and the outer area 7-2 of the annular grouting curtain.

[0120] Step 6.8, repeating steps 6.6 and 6.7, completes the drilling, water pressure test, treatment effect evaluation, grouting reinforcement, and other work for the three-order directional inspection hole 6-5, forming a structure as shown in the figure. Figure 11 The annular grouting curtain shown is 7;

[0121] like Figure 10 As shown, the annular grouting curtain body 7 includes an annular grouting curtain core area 7-1 and an annular grouting curtain peripheral area 7-2. The annular grouting curtain core area 7-1 is the range from the outer wall of the inclined well barrel 1 to the outer boundary of the pore and fracture development area 3 on the outer side of the well barrel. The annular grouting curtain peripheral area 7-2 is the range from the outer boundary of the pore and fracture development area 3 on the outer side of the well barrel to the outer boundary of the pore and fracture development outer boundary area 4.

[0122] like Figure 12 As shown, the annular grouting curtain 7 of the inclined shaft 1 constructed in this invention passes through the loose layer section, as... Figure 13 As shown, the original leakage point of the well shaft is no longer seeping water, the water level outside the well shaft has been restored, and the groundwater flow field and hydrochemical field are stable. The annular grouting curtain body 7 of the inclined well shaft 1 constructed by this invention through the bedrock section has very good effects in loose layers and bedrock with strong water supply.

[0123] Step 7: By monitoring the changes in water level and water quality in the inclined shaft 1 before, during, and after treatment through the online water level and water quality monitoring borehole 8, the groundwater flow field and groundwater chemical field are plotted to monitor and evaluate the water treatment effect in the inclined shaft of the coal mine in the strong water-rich and strongly recharged strata, and to ensure the safe operation of the inclined shaft of the coal mine in the strong water-rich and strongly recharged strata.

Claims

1. A method for treating water in inclined shafts of coal mines, characterized in that, Includes the following steps: Step 1: Investigate the engineering geological and hydrogeological conditions of the inclined shaft of a coal mine with strong water-rich and recharged loose strata, delineate the stratification of the surrounding soil and rock layers, and determine the excavation cross-section height of the inclined shaft. The width of the inclined shaft excavation section B is measured, and the mechanical parameters of the surrounding soil and rock mass, cohesion c and internal friction angle φ, are tested. The number n of leakage points in the inclined shaft and the water level of the loose layer around the inclined shaft are monitored. ; Step 2: Calculate the theoretical radius of the loosened zone of the surrounding rock in the inclined shaft. ; In the formula: R b理 —Theoretical radius of the loosened zone of the surrounding rock in the inclined shaft, in meters; —Equivalent radius of the inclined shaft excavation section, in meters. ; h 筒 —Height of the inclined shaft excavation section, in meters; B—Width of the inclined shaft excavation section, in meters; P—Initial in-situ stress of the surrounding rock of the inclined shaft, MPa, P=γH 埋 ; γ—Solid weight of the rock mass surrounding the inclined shaft, N / m 3 ; H 埋 —Depth of burial casing, m; P1—initial support reaction force of inclined shaft, MPa; c—cohesion of the surrounding rock of the inclined shaft, MPa; φ—Angle of friction within the surrounding rock of the inclined shaft, °; Step 3: Calculate the theoretical radius of the plastic zone of the rock and soil in the inclined shaft. ; In the formula: —Equivalent radius of the inclined shaft excavation section, in meters. ; —Strain of the surrounding rock in the inclined shaft, MPa ; —Slanted well casing support reaction force, MPa; c—cohesion of the soil and rock mass surrounding the inclined shaft, MPa; φ—Angle of friction within the soil and rock surrounding the inclined shaft, °; γ—Unit weight of the overlying rock and soil of the inclined shaft, kN / m 3 ; —Vertical distance from the top of the inclined shaft to the ground surface, in meters; Step 4: Determine the theoretical radius of the loosened zone of the surrounding rock in the inclined shaft. The boundary range of the pore and fracture development area on the outer side of the wellbore; the theoretical radius of the plastic zone of the soil and rock mass in the inclined wellbore. This refers to the boundary range of the outer boundary region where pores and fractures develop. Step 5: Install online monitoring holes for construction water level and water quality on the outside of the inclined shaft, and install a fully automatic monitoring system in the online monitoring holes to monitor the groundwater level, water quality and flow field parameters around the inclined shaft in real time. Step 6: In the area of ​​pore and fracture development on the outside of the inclined well, directional boreholes are arranged along the inclination direction of the well and are parallel to the outer wall of the inclined well. The directional boreholes are constructed in a sequential and segmented manner. The trajectory of the directional boreholes is within the boundary between the inclined well and the area of ​​pore and fracture development on the outside of the well. A ring-shaped grouting curtain is constructed by grouting. Step 7: Monitor the changes in water level and water quality in the inclined shaft before, during and after the treatment by using online water level and water quality monitoring wells; draw groundwater flow field and groundwater chemical field; monitor and evaluate the water treatment effect in the inclined shaft of coal mines in strong water-rich and strongly recharged strata; and ensure the safe operation of the inclined shaft of coal mines in strong water-rich and strongly recharged strata.

2. The method for treating water in inclined shafts of coal mines as described in claim 1, characterized in that, The directional boreholes are multiple and are respectively located at the top, sides and bottom of the inclined shaft.

3. The method for treating water in inclined shafts of coal mines as described in claim 1, characterized in that, The number of directional boreholes m is determined according to the size of the inclined well. When the radius of the inclined well is 2~4, m is 3~5, and when the radius of the inclined well is 4~7, m is 5~6.

4. The method for treating water in inclined shafts of coal mines as described in claim 1, characterized in that, The annular grouting curtain body includes an annular grouting curtain core area and an annular grouting curtain peripheral area; the annular grouting curtain core area is the range from the outer wall of the inclined well to the outer boundary of the pore and fracture development area on the outside of the well, and the annular grouting curtain peripheral area is the range from the outer boundary of the pore and fracture development area on the outside of the well to the outer boundary of the pore and fracture development area.

5. The method for treating water in inclined shafts of coal mines as described in claim 1, characterized in that, In step 6, directional drilling is divided into three phases. The first and second phases both use the hole-to-hole construction process. The third phase hole is used as an inspection hole. When grout leakage is found, the third phase hole is used as a grouting hole for grouting and reinforcement. In directional drilling and grouting, the length L of each segment is 10~50m, when the formation permeability coefficient K < 10. -2 When the speed is cm / s, L is taken as 50m; when 10 -2 When cm / s ≤ K < 1 cm / s, L is 40 m; when 1 cm / s ≤ K < 5 cm / s, L is 30 m; when 5 cm / s ≤ K < 10 cm / s, L is 20 m; when 10 cm / s ≤ K, L is 10 m.

6. The method for treating water in inclined shafts of coal mines as described in claim 5, characterized in that, The directional drilling segmented grouting volume ; Where: Q—the volume of grouting in directional drilling segments; —Permeability coefficient of the formation surrounding the borehole; —Length of directional drilling sections; —Grouting pressure at the orifice of the directional borehole; —Water pressure at the contact front between the borehole diffusion slurry and water; R —Diffusion radius of grouting fluid in directional drilling; r —Radius of directional drilling; μ —The dynamic viscosity of a liquid.

7. The method for treating water in inclined shafts of coal mines as described in claim 6, characterized in that, Step 6, which involves constructing directional drilling and building an annular grouting curtain in a sequential and segmented manner, includes the following steps: Step 6.1: Place the directional drilling rig at the wellhead of the inclined shaft. First, construct the first section length L of the first-sequence directional grouting hole and the first section length L of the first-sequence directional pumping hole. Install the grouting pipe and grouting pressure gauge at the wellhead of the first-sequence directional grouting hole. Grout into the first section length L of the first-sequence directional grouting hole through the grouting pipe. At the same time, lower the pump into the first-sequence directional pumping hole. Use the pump to extract water from the formation near the first section length L of the first-sequence directional pumping hole. The grout in the first-sequence directional grouting hole flows around the well shaft to the first-sequence directional pumping hole. When the water extracted from the first-sequence directional pumping hole changes from clear water to turbid grout, stop pumping and close the valve at the wellhead of the first-sequence directional pumping hole. Continue grouting in the first-sequence directional grouting hole until the grouting flow rate q≤15L / min or the grouting pressure≥2MPa. Then, stop grouting and close the gate valve at the wellhead of the first-sequence directional grouting hole. Step 6.2: Install a grouting pipe and pressure gauge at the orifice of the first-order directional pumping hole. Inject grout into the borehole of length L of the first-order directional pumping hole through the grouting pipe. The grout in the first-order directional pumping hole diffuses around the perimeter of the inclined shaft, filling the space of the core area and the outer area of ​​the annular grouting curtain. Stop grouting when the grouting flow rate q ≤ 15 L / min or the grouting pressure ≥ 2 MPa, and close the gate valve at the orifice of the first-order directional pumping hole. After 12 hours of curing, repeat steps 6.1 to 6.2 to complete the drilling and grouting of the next section of length L of the first-order directional grouting hole and the first-order directional pumping hole, until the drilling and grouting construction of the treatment section of the first-order directional grouting hole and the first-order directional pumping hole is completed. Step 6.3: Construct the first section L of the second-order directional grouting hole and the first section L of the second-order directional pumping hole. Install a grouting pipe and a grouting pressure gauge at the opening of the second-order directional grouting hole. Grout is injected into the borehole of the first section L of the second-order directional grouting hole through the grouting pipe. At the same time, a pump is lowered into the second-order directional pumping hole to pump water out of the borehole from the strata near the first section L of the second-order directional pumping hole. Repeat step 6.3 to complete the drilling and grouting construction of the treatment sections of the second-order directional grouting hole and the second-order directional pumping hole. Step 6.4: Drill the first section of the three-stage directional inspection hole with a length of L and conduct a water pressure test. When the permeability is <0.1Lu, it indicates that the treatment effect of this section is good and has the effect of blocking water and preventing seepage. When the permeability is ≥0.1Lu, it indicates that the treatment effect of this section does not meet the standard and has not achieved an effective effect of blocking water and preventing seepage. Grouting reinforcement is required. Step 6.5, repeat step 6.4, to complete the drilling of the three-order directional inspection holes, water pressure test, treatment effect evaluation, grouting reinforcement, and form an annular grouting curtain.

8. The method for treating water in inclined shafts of coal mines as described in claim 7, characterized in that, In step 6.4, when the water-blocking and seepage prevention effect of the treatment section does not meet the standard, a grouting pipe and a pressure gauge are installed at the orifice of the three-order directional inspection hole to perform three-order grouting reinforcement on the section. The grout enters the three-order directional inspection hole through the grouting pipe to replenish the residual space in the core area and the outer area of ​​the annular grouting curtain.

9. The method for treating water in inclined shafts of coal mines as described in claim 1, characterized in that, The horizontal spacing between the online water level and water quality monitoring holes is 80~100m.

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