Method for treating fault fracture zone through upper and lower combined collaborative grouting of mine

Abstract

The invention discloses a method for treating a fault fracture zone through upper and lower combined cooperative grouting of a mine, and relates to the technical field of fault fracture zone governance, the method comprises the following steps: S1, constructing a slurry conveying drill hole, the lower end of the slurry conveying drill hole is communicated with an underground roadway, and the upper end of the slurry conveying drill hole extends to the ground; s2, a plurality of grouting drill holes are formed in the head-on working face of the underground roadway; s3, a grouting station is arranged on the ground, grout is conveyed to the head-on working face of the underground roadway through the grout conveying drill hole by means of a grouting pipeline, and the grouting pipeline is connected with an orifice of the grouting drill hole to inject the grout into the fault fracture zone through the grouting drill hole; and S4, after the slurry solidifies stones, finishing the work. The slurry conveying distance is short, and the occupied space of the ground is small.

Description

Technical Field

[0001] The present invention relates to the technical field of fault fracture zone treatment, and particularly to a method for jointly grouting and treating a fault fracture zone by cooperation between the surface and underground of a mine. Background Art

[0002] When driving a roadway underground in a mine, it is inevitable to pass through a fault zone. The upper and lower connected fracture zones formed by the fault generally easily form a water passage leading to the upper and lower aquifers, and there are risks of water inrush and collapse during driving through. For relatively large water-bearing faults, reinforcement treatment is generally required.

[0003] In the industry, the grouting method is generally used for reinforcement treatment. The slurry is injected into the voids of the fault fracture zone to form a stone body, which fills and reinforces the fracture zone. According to different grouting methods, it can be divided into grouting in the roadway working face underground and surface grouting.

[0004] Grouting in the roadway working face underground means constructing a borehole at the position of the fault zone in the roadway working face, arranging a grouting pump and a slurry mixing system near the working face, transporting the grouting materials from the wellhead to the slurry mixing system by the mine transportation system, and injecting the prepared slurry into the fracture zone formation through the pipeline and the grouting hole by the grouting pump to achieve the reinforcement treatment of the fault fracture zone. The advantages of this method are: strong pertinence in treatment, the boreholes are arranged around the roadway direction, targeting the roadway area for treatment, and the borehole engineering quantity is small; the second is that the treatment effect can be judged by directly observing the water output of the inspection hole, which is easy to detect. The disadvantages are: it is difficult to transport equipment and materials, especially a large amount of grouting materials, and continuous large-scale grouting cannot be carried out; the roadway space is limited, large grouting equipment cannot be used, the treatment efficiency is low, the construction period is long, and the effect is difficult to guarantee; the working environment of workers is poor and the labor intensity is high.

[0005] Surface grouting treatment means arranging a drilling rig on the ground above the fault, constructing a borehole from the ground to the position of the fault fracture zone, setting up a grouting station on the ground, and injecting the slurry into the fault zone formation through the borehole to achieve the purpose of reinforcement treatment. The advantages of this method are: large grouting pressure, large slurry diffusion distance, and good treatment effect; convenient material transportation, suitable for large-flow continuous grouting; large construction equipment can be used, and the construction efficiency is high; short construction period, low cost, and good working environment for workers. The disadvantages are: it is necessary to occupy land for construction directly above the treatment position, with great coordination difficulty and relatively large social environment risks; the borehole needs to be drilled from the ground to the treatment position, and the roadway depth is generally large, so the borehole engineering quantity is relatively large; high-pressure slurry is easy to string into the existing roadways underground, which is not applicable to the conditions where there are roadways near the treatment area; the effect inspection needs to obtain relevant parameters through hydrogeological tests, which is not as intuitive and convenient as underground.

[0006] For some cases with high governance difficulty and many construction constraints: the fault location is far from the wellhead, the transportation of underground materials and equipment is difficult, and the time for personnel to come and go is long, which is not suitable for grouting in the underground roadway working face; in addition, the construction of the area directly above the governance area is difficult, and the distance between the governance area and the roadway working face is close, so it is not advisable to use the above-mentioned ground grouting method for governance in this case.

[0007] Therefore, there is an urgent need in the art for a new method for jointly and collaboratively grouting to treat fault fracture zones between the surface and underground of a mine to solve the above problems. Summary of the Invention

[0008] The object of the present invention is to provide a method for jointly and collaboratively grouting to treat fault fracture zones between the surface and underground of a mine to solve the problems existing in the above-mentioned prior art, with a short slurry transportation distance and a small land occupation area on the ground.

[0009] To achieve the above object, the present invention provides the following solutions:

[0010] The present invention discloses a method for jointly and collaboratively grouting to treat fault fracture zones between the surface and underground of a mine, including the following steps:

[0011] S1. Construct a slurry transportation borehole, the lower end of the slurry transportation borehole is connected to the underground roadway, and the upper end of the slurry transportation borehole extends to the ground;

[0012] S2. Arrange a plurality of grouting boreholes at the heading working face of the underground roadway;

[0013] S3. Set up a grouting station on the ground, use a grouting pipeline to transport the slurry to the heading working face of the underground roadway through the slurry transportation borehole, and connect the grouting pipeline to the orifice of the grouting borehole to inject the slurry into the fault fracture zone through the grouting borehole;

[0014] S4. After the slurry solidifies and forms stones, the work ends.

[0015] Preferably, the slurry transportation borehole includes a first slurry transportation hole and a second slurry transportation hole, the first slurry transportation hole is located above the second slurry transportation hole, and the inner diameter of the first slurry transportation hole is larger than the inner diameter of the second slurry transportation hole. A first water stop casing is provided in the first slurry transportation hole, and a second water stop casing is provided in the second slurry transportation hole.

[0016] Preferably, when constructing the slurry transportation borehole, first carry out the drilling work of the first slurry transportation hole, install the first water stop casing and carry out the pipe fixing work after the first slurry transportation hole is formed; then drill the second slurry transportation hole in the first water stop casing, and install the second water stop casing and carry out the pipe fixing work inside the second slurry transportation hole after the drilling work of the second slurry transportation hole ends.

[0017] Preferably, the inner diameter of the first grout delivery hole is 244 mm, the outer diameter of the first water-stop casing is 194 mm, and the wall thickness of the first water-stop casing is 5 mm;

[0018] The inner diameter of the second grout delivery hole is 152 mm, the outer diameter of the second water-stop casing is 140 mm, and the wall thickness of the second water-stop casing is 5 mm.

[0019] Preferably, when drilling the second grout delivery hole, first use the first grout delivery drill bit to drill from the bottom of the first grout delivery hole to the underground roadway, and then use the second grout delivery drill bit to continue drilling. The diameter of the hole drilled by the second grout delivery drill bit is larger than the diameter of the hole drilled by the first grout delivery drill bit, and the second grout delivery drill bit drills to above the grout leakage section to form the second grout delivery hole. After placing a wooden plug into the second grout delivery hole for grouting, then place each of the second water-stop casings into the second grout delivery hole in sequence to complete the pipe fixing work of the second grout delivery hole. Then use the first grout delivery drill bit to drill through the second water-stop casing again and pierce the wooden plug to form a drill pipe grout delivery hole.

[0020] Preferably, the grout injection pipeline includes a first grout injection pipe. One end of the first grout injection pipe is connected to the grout source of the grout injection station, the second end of the first grout injection pipe is connected to the grout delivery drill pipe. The grout delivery drill pipe passes through the grout delivery hole, and the lower end of the grout delivery drill pipe is communicated with the grout injection hole through a second grout injection pipe.

[0021] Preferably, a wire-passing steel pipe is connected to the grout delivery drill pipe.

[0022] Preferably, when opening the grout injection hole, first use the first grout injection drill bit to drill a hole, and then lower the hole mouth pipe; then change to the second grout injection drill bit to drill. The drilling diameter of the second grout injection drill bit is smaller than the drilling diameter of the first grout injection drill bit. The second grout injection drill bit stops drilling in front of the fault fracture zone, and then install the pressure-bearing grout injection pipe; finally, change to the third grout injection drill bit to drill until the final hole depth of the grout injection hole is reached.

[0023] Preferably, there are seven grout injection holes, namely the first grout injection hole, the second grout injection hole, the third grout injection hole, the fourth grout injection hole, the fifth grout injection hole, the sixth grout injection hole and the seventh grout injection hole. In addition, two inspection holes are drilled on the heading face of the underground roadway;

[0024] The first grout injection hole and the fifth grout injection hole are 1 m away from the bottom surface of the underground roadway. The distance between the first grout injection hole and the left side of the underground roadway and the distance between the fifth grout injection hole and the right side of the underground roadway are both 0.5 m;

[0025] The second grouting hole and the fourth grouting hole are 2 m away from the bottom surface of the underground roadway, and the distances between the second grouting hole and the left side of the underground roadway and between the fourth grouting hole and the right side of the underground roadway are both 0.5 m.

[0026] Preferably, when drilling each of the grouting holes;

[0027] First, conduct the first round of drilling, that is, drill the first grouting hole, the second grouting hole, the third grouting hole, the fourth grouting hole, and the fifth grouting hole, measure the hole deviation, draw the landing point diagram of the drilling trajectory of the grouting section cross-section, comprehensively analyze the grouting effect of the first round, and determine the grouting parameters for the second round;

[0028] Conduct the second round of drilling and construct the sixth grouting hole and the seventh grouting hole;

[0029] Conduct the third round of drilling and construct two inspection holes.

[0030] The present invention has achieved the following technical effects compared with the prior art:

[0031] The present invention constructs grouting holes at the heading face of the underground roadway, and simultaneously constructs slurry transportation holes and a grouting station at a suitable position on the ground. After the construction of the slurry transportation holes is completed, install slurry transportation pipelines to connect the ground grouting station with the grouting holes in the underground roadway, so as to realize the grouting of the rock mass in the fault zone by the ground grouting station through the grouting holes. The present invention avoids the disadvantages of underground or ground grouting, can not only shorten the transportation distance of the slurry, but also reduce the ground occupation rate, and realizes the high-quality and high-efficiency treatment of the fault fracture zone. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] 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 embodiments. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0033] Figure 1 It is the working principle diagram of the method for jointly and cooperatively grouting and treating the fault fracture zone by the present invention in the mine;

[0034] Figure 2 It is the distribution diagram of grouting holes in the method for jointly and cooperatively grouting and treating the fault fracture zone by the present invention in the mine;

[0035] In the figure: 1 - slurry injection borehole; 101 - first slurry injection hole; 1011 - first water stop casing; 102 - second slurry injection hole; 1021 - second water stop casing; 2 - underground roadway; 3 - grouting borehole; 301 - first grouting hole; 302 - second grouting hole; 303 - third grouting hole; 304 - fourth grouting hole; 305 - fifth grouting hole; 306 - sixth grouting hole; 307 - seventh grouting hole; 4 - pressure grouting pipe; 5 - fault fracture zone; 6 - grouting pump; 7 - distribution box; 8 - inspection hole. Detailed implementation manners

[0036] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying 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 shall fall within the protection scope of the present invention.

[0037] The purpose of the present invention is to provide a method for jointly and cooperatively grouting to treat the fault fracture zone between the surface and the underground of a mine, so as to solve the problems existing in the above-mentioned prior art, such as short slurry transportation distance and small land occupation area on the ground.

[0038] To make the above-mentioned objects, features and advantages of the present invention more obvious and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific implementation manners.

[0039] As Figure 1 - Figure 2 shown, this embodiment provides a method for jointly and cooperatively grouting to treat the fault fracture zone between the surface and the underground of a mine, including the following steps:

[0040] S1. Construct the slurry injection borehole 1, the lower end of the slurry injection borehole 1 is connected to the underground roadway 2, and the upper end of the slurry injection borehole 1 extends to the ground.

[0041] S2. Arrange a plurality of grouting boreholes 3 at the heading face of the underground roadway 2, and the specific number of the grouting boreholes 3 can be adjusted according to actual needs.

[0042] S3. Set up a grouting station on the ground. The grouting station is an existing mature facility, which includes existing equipment such as a grouting pump 6, a distribution box 7 and a slurry mixing machine (or slurry stirring equipment) (of course, it also includes some other necessary equipment in the grouting station, and these are all prior arts and will not be described one by one). Use the grouting pipeline to transport the slurry to the heading face of the underground roadway 2 through the slurry injection borehole 1. The grouting pump 6 can use the existing BQ350 type grouting pump 6 to provide the transportation power for the grouting pipeline. The grouting pump 6 is used to transport the well-stirred slurry in the slurry stirring equipment to the slurry injection borehole 1 through the grouting pipeline. The grouting pipeline is connected to the orifice of the grouting borehole 3 to inject the slurry into the fault fracture zone 5 through the grouting borehole 3.

[0043] S4. After the slurry solidifies and forms a stone, an effective water-blocking curtain is formed outside the contour of the preset underground roadway 2, and the work ends here. This facilitates the subsequent safe passage of the underground roadway 2 through the fault fracture zone 5.

[0044] In this embodiment, the grouting borehole 1 is formed by segmented drilling, so the grouting borehole 1 includes a first grouting hole 101 and a second grouting hole 102. The first grouting hole 101 is located above the second grouting hole 102, and the inner diameter of the first grouting hole 101 is larger than that of the second grouting hole 102. A first water-stop casing 1011 is provided in the first grouting hole 101, and the outer diameter of the first water-stop casing 1011 is smaller than the inner diameter of the first grouting hole 101. Similarly, a second water-stop casing 1021 is provided in the second grouting hole 102, and the outer diameter of the second water-stop casing 1021 is smaller than the inner diameter of the second grouting hole 102.

[0045] In this embodiment, when constructing the grouting borehole 1, first carry out the drilling work of the first grouting hole 101. After the first grouting hole 101 is formed, install the first water-stop casing 1011 and carry out the pipe-fixing work. As for the pipe-fixing work of the first water-stop casing 1011, inject slurry into the first water-stop sleeve pipe. The slurry will flow into the annular gap between the first water-stop casing 1011 and the first grouting hole 101 through the side wall through holes of the first water-stop casing 1011 to prevent the water in the upper aquifer from being introduced into the underground roadway 2. When the slurry solidifies, the fixation of the first water-stop casing 1011 can be completed, and a closed water-stop inspection is carried out on the pipe-fixing quality to ensure the closed quality of the first water-stop casing 1011.

[0046] Then drill the second grouting hole 102 in the first water-stop casing 1011. After the drilling work of the second grouting hole 102 is completed, install the second water-stop casing 1021 inside the second grouting hole 102 and carry out the pipe-fixing work.

[0047] It should be noted here that for the construction of the grouting borehole 1, the equipment used in this embodiment is the existing TSJ-2000 water source drill and the drill tower structure. Among them, the power of the TSJ-2000 water source drill adopts a rotary drive mode, which is commonly used for coal mine freezing and grouting hole drilling, and has the characteristics of high drilling efficiency and strong adaptability. It uses drill pipes in the ordinary drilling industry, and the commonly used one is of the φ73mm specification.

[0048] In addition, during the construction of the slurry injection borehole 1, if only relying on the TSJ-2000 water source drill, the slurry injection borehole 1 may have the problem of deviation. Therefore, it can also be used in combination with a directional drilling tool: the drilling tool combination uses a common drilling tool plus a positive displacement downhole motor. Among them, the positive displacement downhole motor uses drilling fluid as power and converts the liquid pressure energy into mechanical energy. When the slurry pumped out by the mud pump flows through the bypass valve and enters the motor, a certain pressure difference is formed at the inlet and outlet of the motor, pushing the rotor to rotate around the axis of the stator, and transmitting the rotational speed and torque to the drill bit through the universal joint shaft and the transmission shaft. The universal joint shaft and the rod body can be designed as 1°, 1.5°, or 1.75° according to needs. Using the positive displacement downhole motor can effectively make up for the deviation of the vertical angle drilling of the slurry injection borehole 1. These are all common equipment in the drilling field, so the connection relationship and working principle will not be elaborated here.

[0049] In this embodiment, the inner diameter of the first slurry injection hole 101 is 244 mm, the outer diameter of the first water stop casing 1011 is 194 mm, and the wall thickness of the first water stop casing 1011 is 5 mm. The inner diameter of the second slurry injection hole 102 is 152 mm, the outer diameter of the second water stop casing 1021 is 140 mm, and the wall thickness of the second water stop casing 1021 is 5 mm. Of course, those skilled in the art can also adjust the specific dimensions of each component in the slurry injection borehole 1 according to actual needs, not limited to just this one.

[0050] In this embodiment, when drilling the second slurry injection hole 102, first use the first slurry injection drill bit to drill from the bottom of the first slurry injection hole 101 to the underground roadway 2. At this time, the drilled hole diameter is 118 mm. Then use the second slurry injection drill bit to continue drilling. The hole diameter drilled by the second slurry injection drill bit is larger than the hole diameter drilled by the first slurry injection drill bit. At this time, the drilled hole diameter is 152 mm. And the second slurry injection drill bit drills to about 1 m above the slurry leakage section to form the second slurry injection hole 102. Generally, the slurry leakage section is at a position about 1 - 2 m above the underground roadway 2. After placing a wooden plug into the second slurry injection hole 102, grout is injected into it. Then, each second water stop casing 1021 is placed into the second slurry injection hole 102 in sequence. At this time, the second water stop casing 1021 will be installed into the second slurry injection hole 102 filled with slurry in sequence. Of course, some slurry will also flow into the annular gap between the second water stop casing 1021 and the second slurry injection hole 102, so as to realize the pipe fixing work of the second slurry injection hole 102. This method is the single-fluid cement slurry grouting method. After the slurry solidifies and has strength, a closed water stop inspection is carried out on the fixed pipe. Then use the first slurry injection drill bit (118 mm hole diameter) to drill through the wooden plug again from the second water stop casing 1021 to form a drill pipe slurry injection hole, and the slurry on the ground will flow into the underground roadway 2 through the drill pipe slurry injection hole.

[0051] During the installation process of the second water-stop casing 1021, the second water-stop casings 1021 are connected in sequence from top to bottom, and two adjacent second water-stop casings 1021 are connected by threads. After a second water-stop casing 1021 is installed in place, the pipe string (or inner casing) connected to its upper end can be rotated in the reverse direction to release its connection with the second water-stop casing 1021, that is, the installation of the second water-stop casing 1021 is realized. This installation method is called the pipe-throwing method in the industry, which can effectively prevent collapse.

[0052] In addition, it can be seen from Figure 1 that the upper end of the second slurry injection hole 102 (and the second water-stop casing 1021 at the uppermost position) will extend into a part of the first slurry injection hole 101 (and the lower end of the first water-stop casing 1011 at the lowermost position), forming an overlapping area, and the overlapping length is 10 m, which can further improve the water-stop effect.

[0053] In this embodiment, the grouting pipeline includes a first grouting pipe. One end of the first grouting pipe is connected to the slurry source of the grouting station (i.e., connected to the outlet of the grouting pump 6), and the second end of the first grouting pipe is connected to a grouting drill pipe with a diameter of 60 mm. The grouting drill pipe passes through the grouting hole 1, and the inside of the grouting drill pipe has a channel for transporting slurry. The lower end of the grouting drill pipe is communicated with the grouting hole 3 through a second grouting pipe.

[0054] During actual use, the slurry in the grouting station is transported to the upper end of the grouting drill pipe through the first grouting pipe. The slurry flows downward through the center of the grouting drill pipe, and the slurry flowing out of the grouting drill pipe then flows into the grouting hole 3 through the second grouting pipe.

[0055] In this embodiment, the grouting drill pipe is connected with a wire-passing steel pipe. The wire-passing steel pipe is an existing one-inch steel pipe (i.e., with a diameter of 1 inch). The wire-passing steel pipe can be tied to one side of the grouting drill pipe by a rope, and a telephone line is lowered into the inside of the wire-passing steel pipe for use in communication between the wellhead and the underground.

[0056] In this embodiment, when opening the grouting borehole 3, first use the first grouting drill bit to drill a hole. At this time, the hole diameter is 171 mm. Then, lower a casing pipe with a diameter of 159 mm, and the length of the casing pipe is not less than 3 m. Then, fill the inside with grout for pipe fixing operation. After the pipe fixing is dry, apply a pressure of not less than 1 MPa. Then, replace it with the second grouting drill bit to drill a hole. The drilling diameter of the second grouting drill bit is smaller than that of the first grouting drill bit. At this time, the hole diameter of the drilling is 133 mm. The second grouting drill bit stops drilling in front of the fault fracture zone 5, specifically stops in front of the fault fracture zone 5 and the distance is 5 m (the specific distance can be adjusted according to the actual situation). Then, install a pressure-bearing grouting pipe 4 with a diameter of 127 mm. After lowering the pressure-bearing grouting pipe 4, then introduce grout for pipe fixing. After the pipe fixing is dry, apply a pressure of not less than 12 MPa to ensure the stability and safety of the pressure-bearing grouting pipe 4. Finally, replace it with the third grouting drill to drill a hole. The third grouting drill drills to the final hole depth of the grouting borehole 3. The grouting borehole 3 should exceed the fault fracture zone 5, and the final hole depth of the grouting borehole 3 is located about 10 m behind the fault fracture zone 5 (this distance can also be adjusted according to actual needs). After the grouting borehole 3 is completed, connect the second grouting pipe and grout the grouting section (i.e., near the fault fracture zone 5). Grouting can be carried out at any time when encountering fragmentation and water inflow during the drilling process.

[0057] In this embodiment, as Figure 2 shown, there are seven grouting boreholes 3, namely the first grouting hole 301, the second grouting hole 302, the third grouting hole 303, the fourth grouting hole 304, the fifth grouting hole 305, the sixth grouting hole 306 and the seventh grouting hole 307. In addition, two inspection holes 8 are drilled on the heading working face of the underground roadway 2. The specific setting positions of each grouting hole are as follows:

[0058] First of all, the first grouting hole 301 and the fifth grouting hole 305 are 1 m away from the bottom surface of the underground roadway 2. The distance between the first grouting hole 301 and the left side of the underground roadway 2 is the same as the distance between the fifth grouting hole 305 and the right side of the underground roadway 2, both of which are 0.5 m.

[0059] The second grouting hole 302 and the fourth grouting hole 304 are 2 m away from the bottom surface of the underground roadway 2. The distance between the second grouting hole 302 and the left side of the underground roadway 2 is the same as the distance between the fourth grouting hole 304 and the right side of the underground roadway 2, both of which are 0.5 m.

[0060] The third grouting hole 303 is located at the midpoint between the second grouting hole 302 and the fourth grouting hole 304. Therefore, the third grouting hole 303 is 2 m away from the bottom surface of the underground roadway 2.

[0061] As for the specific positions of the sixth grouting hole 306, the seventh grouting hole 307, and the two inspection holes 8, they can be adjusted according to actual needs and are not limited herein.

[0062] In this embodiment, when drilling each grouting hole 3, a ZDY-4000S type hydraulic drill is used. This drill is convenient and flexible, has a large torque, and is mostly used for the construction of underground roadways 2. Its drill pipe uses a φ73mm spiral drill pipe. The specific working sequence is as follows:

[0063] Before drilling, first calculate the opening horizontal azimuth and the opening up-and-down angle of the first-round grouting holes, so that the landing points of the grouting holes 3 on the cross-section behind the fault fracture zone 5 along the direction of the underground roadway 2 are on the contour line of the underground roadway 2. The specific meaning of this sentence is that, as can be seen from Figure 1 the grouting holes 3 are inclined holes, and the end points of the grouting holes 3 will exceed the fault fracture zone 5. Then Figure 1 the landing points of the grouting holes 3 on the cross-section behind the fault fracture zone 5 (i.e., the right side of Figure 1 ) are exactly at the edge position of the underground roadway 2. Specifically, the first grouting hole 301 and the second grouting hole 302 may be at the left edge position of the underground roadway 2 when on the cross-section behind the fault fracture zone 5, the fourth grouting hole 304 and the fifth grouting hole 305 may be at the right edge position of the underground roadway 2 when on the cross-section behind the fault fracture zone 5, and the third grouting hole 303 may be at the top edge position of the underground roadway 2 when on the cross-section behind the fault fracture zone 5.

[0064] The vertical depth of the grouting holes 3 along the direction of the underground roadway 2 exceeds the fault fracture zone 5 by about 10m. Since the use of a ground grouting system can achieve large-flow continuous high-pressure grouting, the grouting holes 3 are used for grouting the fault fracture layer with the section from 5m away from the fault fracture zone 5 to the bottom hole depth (i.e., 10m beyond the fault fracture zone 5) as the grouting section.

[0065] Perform the first-round drilling, that is, drill the first grouting hole 301, the second grouting hole 302, the third grouting hole 303, the fourth grouting hole 304, and the fifth grouting hole 305, lower the pressure-bearing grouting pipe 4 and complete pipe fixation. After the drilling reaches the bottom hole depth, grout the formation of the grouting section in batches. After the first grouting, wait for it to solidify and then perform the second grouting or even multiple times until the qualified standard is reached. Then use a fiber optic gyro to measure the hole deviation, draw the drilling trajectory landing point diagram of the grouting section, comprehensively analyze the effect of the first-round grouting, determine the parameters of the second-round grouting, and the second-round drilling structure and drilling depth are the same as those of the first-round drilling.

[0066] Perform the second-round drilling and construct the sixth grouting hole 306 and the seventh grouting hole 307.

[0067] Perform the third round of drilling and construct two inspection holes 8. The depth of the inspection holes is the same as that of the grouting holes 3. After drilling the inspection holes 8, observe whether there is water gushing out in the inspection holes. If there is water gushing out, it indicates that the grouting effect is not good. If there is no water gushing out, grout until the qualified standard is reached and strengthen the grouting quality of the fault fracture zone 5.

[0068] Accurately calibrate and recheck the opening positions, azimuths (horizontal direction), and dips (vertical direction) of each grouting hole 3 to ensure the accurate opening of the grouting holes 3. When opening the grouting holes 3, reasonably set the pre-deviation amount according to the actual natural deviation (self-weight) during construction. The drill pipe generally inclines upward by 1-2°.

[0069] In addition, due to the construction of the grouting holes 3 at the heading face being restricted by the position space of the underground roadway 2, only one drilling rig can be used to construct each grouting hole 3 one by one. Adopt the method of cross-operation for each hole. During the period when one hole is waiting for the pipe to solidify and dry, construct other holes, and overall construct all the grouting holes 3 to achieve the maximum construction efficiency and effectively shorten the construction period.

[0070] In this embodiment, the slurry used for grouting is mainly single-liquid cement slurry, and clay-thickened cement slurry is supplemented when necessary.

[0071] Single-liquid cement slurry: The slurry material is prepared with PO42.5 grade ordinary Portland cement. The advantages of single-liquid cement slurry are good cementation, high stone strength, and convenient slurry preparation. The slurry injection should be first thin (the mass ratio of water to cement is 1:1) and then thick (the mass ratio of water to cement is 0.6-0.8:1). During the initial grouting, a large amount of continuous injection should be carried out. After the slurry starts to set and the hole is refilled, grout again. When the pressure does not rise for a long time during the grouting of a certain ratio of slurry, adjust the slurry concentration. When necessary, add 3-5% (by mass) of water glass to the single-liquid slurry to thicken the slurry and shorten the initial setting time. Clay-thickened cement slurry is to add a certain amount of bentonite to the single-liquid cement slurry to improve the injectability of the single-liquid slurry, enhance the diffusion ability, and strengthen the water blocking effect.

[0072] The calculation of the grouting volume adopts the following formula:

[0073] Q = A × S × n × h × β / m

[0074] In the formula: S - the average cross-sectional area of the grouting section of the roadway, according to the diffusion range; A - the slurry loss coefficient is taken as 1.5; n - the average fissure rate, 15%; h - the length of the grouting section, determined according to the height; β - the slurry filling coefficient, 0.9; m - the slurry solidification rate, 0.85.

[0075] Calculate the expected grouting volume of the slurry, which is only for reference of the expected grouting volume during specific construction. Execute according to the grouting end standard, and take the actual grouting volume as the standard.

[0076] Grouting completion criteria: Final volume ≤ 100 L / min, grouting pressure rising regularly, final pressure reaching above 6 MPa. The time for maintaining the final grouting pressure and final volume for 20 min is qualified.

[0077] In the present invention, specific examples are used to elaborate on the principle and implementation manner of the present invention. The description of the above embodiments is only used to help understand the method and its core idea of the present invention; at the same time, for those of ordinary skill in the art, according to the idea of the present invention, there will be changes in the specific implementation manner and application scope. In summary, the content of this specification should not be construed as a limitation to the present invention.

Claims

1. A method for treating fault fracture zones by joint grouting in a mine, characterized in that: The following steps are involved: S1, constructing a slurry delivery borehole (1), wherein the lower end of the slurry delivery borehole (1) is connected to the underground tunnel (2), and the upper end of the slurry delivery borehole (1) extends to the ground; S2, arranging a plurality of grouting holes (3) on the front working surface of the underground tunnel (2); S3, setting up a grouting station on the ground, using a grouting pipeline to transport the slurry to the head working face of the underground tunnel (2) through the grouting borehole (1), and connecting the grouting pipeline to the orifice of the grouting borehole (3) to inject the slurry into the fault fracture zone through the grouting borehole (3); S4. After the slurry solidifies into stone, the work is finished.

2. The method for treating fault fracture zones by joint grouting in a mine according to claim 1 is characterized in that: The slurry delivery borehole (1) comprises a first slurry delivery hole (101) and a second slurry delivery hole (102); the first slurry delivery hole (101) is located above the second slurry delivery hole (102), and the inner diameter of the first slurry delivery hole (101) is larger than the inner diameter of the second slurry delivery hole (102); a first water stop casing (1011) is provided in the first slurry delivery hole (101), and a second water stop casing (1021) is provided in the second slurry delivery hole (102).

3. The method for treating fault fracture zones by joint grouting in a mine according to claim 2 is characterized in that: When constructing the grouting borehole (1), the first grouting hole (101) is firstly drilled. After the first grouting hole (101) is formed, the first water-stopping sleeve (1011) is installed and the pipe fixing work is performed; then, the second grouting hole (102) is drilled in the center of the first water-stopping sleeve (1011). After the drilling work of the second grouting hole (102) is completed, the second water-stopping sleeve (1021) is installed inside the second grouting hole (102) and the pipe fixing work is performed.

4. The method for treating fault fracture zones by upper and lower joint grouting in a mine according to claim 3 is characterized in that: The inner diameter of the first slurry delivery hole (101) is 244 mm, the outer diameter of the first waterproof casing (1011) is 194 mm, and the wall thickness of the first waterproof casing (1011) is 5 mm; The inner diameter of the second slurry delivery hole (102) is 152 mm, the outer diameter of the second water-stopping sleeve (1021) is 140 mm, and the wall thickness of the second water-stopping sleeve (1021) is 5 mm.

5. The method for treating fault fracture zones by upper and lower joint grouting in a mine according to claim 3 is characterized in that: When drilling the second slurry delivery hole (102), the first slurry delivery drill bit is first used to drill from the bottom of the first slurry delivery hole (101) to the underground tunnel (2), and then the second slurry delivery drill bit is used to continue drilling. The hole diameter drilled by the second slurry delivery drill bit is larger than the hole diameter drilled by the first slurry delivery drill bit, and the second slurry delivery drill bit drills to the top of the slurry leakage section to form the second slurry delivery hole (102). A wooden plug is placed in the second slurry delivery hole (102) and grouting is performed. Then, each of the second water-stopping sleeves (1021) is placed in the second slurry delivery hole (102) in turn, thereby achieving the second slurry delivery hole (102) fixing work. Then, the first slurry delivery drill bit is used to drill again from the second water-stopping sleeve (1021) and sweep through the wooden plug, thereby forming a drill rod slurry delivery hole.

6. The method for treating fault fracture zones by joint grouting in a mine according to claim 1 is characterized in that: The grouting pipeline comprises a first grouting pipe, one end of which is connected to a slurry source of the grouting station, the second end of which is connected to a grouting drill rod, the grouting drill rod passes through the grouting borehole (1), and the lower end of the grouting drill rod is connected to the grouting borehole (3) via a second grouting pipe.

7. The method for treating fault fracture zones by upper and lower joint grouting in a mine according to claim 6 is characterized in that: The slurry delivery drill rod is connected with a line-through steel pipe.

8. The method for treating fault fracture zones by upper and lower joint grouting in a mine according to claim 1 is characterized in that: When drilling the grouting borehole (3), first use the first grouting drill bit to drill the hole, and then insert the orifice pipe; then use the second grouting drill bit to drill the hole, the drilling diameter of the second grouting drill bit is smaller than the drilling diameter of the first grouting drill bit, the second grouting drill bit drills to the front of the fault fracture zone and stops, and then installs the pressure grouting pipe; finally, use the third grouting drill bit to drill the hole, and the third grouting drill hole is drilled to the final hole depth of the grouting borehole (3).

9. The method for treating fault fracture zones by upper and lower joint grouting in a mine according to claim 1 is characterized in that: The grouting boreholes (3) are provided with seven, namely a first grouting hole (301), a second grouting hole (302), a third grouting hole (303), a fourth grouting hole (304), a fifth grouting hole (305), a sixth grouting hole (306) and a seventh grouting hole (307); in addition, two inspection holes (8) are drilled on the front working surface of the underground tunnel (2); The first grouting hole (301) and the fifth grouting hole (305) are 1 m away from the bottom surface of the underground tunnel (2); the distance between the first grouting hole (301) and the left side of the underground tunnel (2) and the distance between the fifth grouting hole (305) and the right side of the underground tunnel (2) are both 0.5 m; The second grouting hole (302) and the fourth grouting hole (304) are 2 m away from the bottom surface of the underground tunnel (2); the distance between the second grouting hole (302) and the left side of the underground tunnel (2) and the distance between the fourth grouting hole (304) and the right side of the underground tunnel (2) are both 0.5 m.

10. The method for treating fault fracture zones by upper and lower joint grouting in a mine according to claim 9, characterized in that: When drilling into each of the grouting boreholes (3); Firstly, a first round of drilling is performed, i.e., the first grouting hole (301), the second grouting hole (302), the third grouting hole (303), the fourth grouting hole (304) and the fifth grouting hole (305) are drilled, hole inclination is measured, a point diagram of the drilling trajectory of the grouting section section is drawn, the effect of the first round of grouting is comprehensively analyzed, and the parameters of the second round of grouting are determined; Perform a second round of drilling to construct the sixth grouting hole (306) and the seventh grouting hole (307); The third round of drilling is carried out to construct two inspection holes (8).

Images