An efficient method for grouting hole distribution

Abstract

The application discloses a high-efficiency grouting hole arrangement method, which comprises the following steps: obtaining a geological sketch, analyzing and determining surrounding rock fissures which have an influence on cavern excavation, determining a drilling hole route with the highest intersection rate with the surrounding rock fissures, performing drilling hole construction according to the drilling hole route, performing grouting operation, and checking grouting effect, etc. The high-efficiency grouting hole arrangement method is based on the intersection rate theory, and the longer the intersection of a single hole and fissures, the greater the intersection rate, the better the groutability, and the better the grouting effect. Compared with a conventional grouting design hole perpendicular to a rock surface, the high-efficiency grouting hole arrangement method is simple in principle, easy to understand, convenient to operate, has more fissure plugging, has good leak stopping effect, and is suitable for grouting water plugging operation of water conservancy and hydropower underground tunnel engineering, underground oil storage and gas storage engineering.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of engineering construction technology, in particular to a high-efficiency grouting hole arrangement method. BACKGROUND

[0002] The effect of underground cavern grouting water plugging is reflected in the number of fissures filled with slurry. Generally speaking, the more fissures in surrounding rock that are plugged by slurry, the better the effect of underground cavern grouting water plugging. The conventional grouting hole direction of underground cavern is perpendicular to the excavated rock surface. This hole arrangement method uses multiple and dense holes to increase the number of intersections between grouting holes and fissures to achieve the purpose of grouting water plugging. It is found in actual construction that: although the orifice of some vertical holes is at the water seepage point position, it deviates from the direction of fissures inside the rock mass, and even has no intersection with the fissures inside the rock mass, with a nearly zero intersection rate. Therefore, this hole arrangement method cannot achieve the best hole angle, has a low intersection rate, and greatly reduces the grouting effect. Thus, the vertical hole arrangement method has poor pertinence, low grouting efficiency, large engineering quantity, and high cost. SUMMARY

[0003] The present application provides a high-efficiency grouting hole arrangement method to replace the existing conventional grouting hole direction design of underground cavern perpendicular to the rock surface. The high-efficiency grouting hole arrangement method fully utilizes the fissure trend to solve the problems of small intersection rate and low grouting efficiency caused by traditional vertical grouting.

[0004] The technical scheme adopted by the present application is as follows:

[0005] A high-efficiency grouting hole arrangement method based on the intersection rate theory, specifically comprising the following steps:

[0006] Step one, obtaining a geological sketch of the current working face of the underground cavern;

[0007] Step two, obtaining a surrounding rock fissure and cavern excavation position intersection graph based on the geological sketch combined with the cavern excavation position design graph, and determining the surrounding rock fissures that affect the cavern excavation through the analysis of the surrounding rock fissure and cavern excavation position intersection graph;

[0008] Step three, determining the drilling hole route with the highest intersection rate with the surrounding rock fissure according to the angle and position of the surrounding rock fissure;

[0009] Step four, drilling the hole according to the drilling hole route to form a grouting hole;

[0010] Step five, performing grouting operation through the drilling hole route with the highest intersection rate with the surrounding rock fissure;

[0011] Step six, obtaining the geological sketch of the designed excavation area of the underground cavern again to check the grouting effect.

[0012] Further, the geological sketch is obtained in the following manner:

[0013] S1, the infrared camera takes a picture to obtain a current tunnel mileage face image;

[0014] S2, the obtained face image is pre-processed;

[0015] S3, the pre-processed image is edge detected to obtain an image structure surface boundary line;

[0016] S4, after edge detection, boundary extraction is performed to obtain face bedding joint information;

[0017] S5, the current face geological sketch is drawn in combination with the bedding joint information, and the joint and fracture trend in the rock is marked.

[0018] Further, in the step two, when the surrounding rock fissure intersecting with the tunnel excavation position graph is analyzed and determined to be a single surrounding rock fissure affected by the tunnel excavation, and the surrounding rock fissure intersects with the tunnel crown or the excavation face, the connecting line between the intersection point of the surrounding rock fissure and the tunnel excavation face and the center point of the surrounding rock fissure is taken as the along-seam hole arrangement.

[0019] Further, in the step two, when the surrounding rock fissure intersecting with the tunnel excavation position graph is analyzed and determined to be a plurality of intersecting surrounding rock fissures affected by the tunnel excavation, and the plurality of intersecting surrounding rock fissures all intersect with the tunnel crown or the excavation face, the connecting line between the highest intersection point of the plurality of intersecting surrounding rock fissures and the tunnel crown or the excavation face is taken as the through hole arrangement.

[0020] Further, in the step two, when the surrounding rock fissure intersecting with the tunnel excavation position graph is analyzed and determined to be a plurality of intersecting surrounding rock fissures affected by the tunnel excavation, and the plurality of intersecting surrounding rock fissures all intersect with the tunnel crown or the excavation face, and the intersection points of the plurality of intersecting surrounding rock fissures with the tunnel crown and the excavation face are at the same height, the intersection point of the surrounding rock fissure with the tunnel crown is selected as the parallel hole arrangement.

[0021] Further, in the step two, when the surrounding rock fissure intersecting with the tunnel excavation position graph is analyzed and determined to be a plurality of intersecting surrounding rock fissures affected by the tunnel excavation, and the plurality of intersecting surrounding rock fissures all intersect with the tunnel crown or the excavation face, and the intersection points of the plurality of intersecting surrounding rock fissures with the tunnel crown and the excavation face are at the same height, the intersection point of the surrounding rock fissure with the tunnel crown is selected as the parallel hole arrangement.

[0022] Further, the calculation method of the intersection rate is:

[0023] r=L0 / L

[0024] In the formula, L is the hole depth, L0 is the intersection length, and r is the intersection rate.

[0025] Furthermore, the grouting holes adopt a diameter of φ42mm, and the spacing, number, and depth of the holes are determined according to the distribution and characteristics of the water leakage fissures in the surrounding rock, as well as the grouting pressure and the grout diffusion range.

[0026] Furthermore, the location of the grouting hole should be selected so that the bottom of the grouting hole intersects with the leakage crack, and the location should be selected at the part with the largest leakage. For horizontal cracks, it is advisable to make an inclined hole from bottom to top; for vertical cracks, it is advisable to make a straight hole directly opposite the crack.

[0027] Furthermore, the spacing of the grouting holes should be determined based on the leakage pressure, crack size, leakage volume, and grout diffusion radius. A simulation test should be conducted before grouting, and the spacing should be adjusted based on the effect check during the grouting process.

[0028] The beneficial effects of this invention are:

[0029] This efficient grouting borehole layout method includes steps such as obtaining geological sketches, analyzing and identifying surrounding rock fissures that affect tunnel excavation, determining the drilling route with the highest intersection rate with the surrounding rock fissures, drilling according to the drilling route, grouting operations, and checking the grouting effect. This efficient grouting borehole layout method is based on the intersection rate theory. The longer the intersection of a single borehole with a fissure, the greater the intersection rate, the better the groutability, and the higher the grouting effect. Compared with conventional system grouting design boreholes perpendicular to the rock surface, this efficient grouting borehole layout method is simple and easy to understand, convenient to operate, seals more fissures, and has a good leak-stopping effect. It is suitable for grouting and water-stopping operations in underground tunnel projects for water conservancy and hydropower, underground oil depots, and gas storage projects. Attached Figure Description

[0030] Figure 1 This is a geological sketch of the present invention;

[0031] Figure 2 This is a schematic diagram of the intersection rate of the present invention;

[0032] Figure 3 This is a schematic diagram of the intersection rate comparison of the present invention;

[0033] Figure 4 This is a schematic diagram of the drilling route for a single surrounding rock fracture according to the present invention;

[0034] Figure 5 This is a schematic diagram of the drilling route when multiple intersecting surrounding rock fissures of the present invention intersect with the tunnel roof arch or the excavation face.

[0035] Figure 6 This is a schematic diagram of the drilling route when multiple intersecting surrounding rock fissures are roughly parallel and at the same height as the intersection of the tunnel arch and the excavation face.

[0036] Figure 7 This is a schematic diagram of the drilling route when there is no intersection between the surrounding rock fissure and the cavern arch or excavation face.

[0037] Figure 8 Figure 1 is a schematic diagram of a drilling route in the presence of various surrounding rock fissures according to the present application. DETAILED DESCRIPTION

[0038] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings of the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by a person of ordinary skill in the art without creative effort belong to the scope of protection of the present application.

[0039] The present embodiment provides a high-efficiency grouting hole arrangement method, which is based on the theory of intersection rate, i.e. the percentage of a fissure in a grouting hole. The longer the intersection of a single hole and a fissure, the greater the intersection rate, the better the groutability, and the higher the grouting effect.

[0040] The high-efficiency grouting hole arrangement method specifically includes the following steps:

[0041] Step 1: Obtain a geological sketch of the current working face of an underground cavern, mainly including faults, joints, dikes, etc. The geological sketch is obtained in the following manner.

[0042] S1: Take pictures of the overall and detailed features of the tunnel working face and side wall using an infrared camera to obtain the working face and side wall images of the current cavern mileage;

[0043] S2: Perform image preprocessing on the obtained working face images;

[0044] Image preprocessing: Since the infrared emitting diode fill light is used for close-range photography, there is inevitably a problem of uneven illumination. The image preprocessing is mainly to address the problem of uneven brightness of the images due to the illumination. Before taking pictures, first measure the distribution of the light intensity of the working face, and according to the measurement results, obtain the light intensity distribution curves in the horizontal and vertical directions. According to the distribution curves, perform brightness equalization processing on the taken pictures to eliminate the effects of overexposure and underexposure. For the images after brightness equalization processing, perform clustering analysis and edge detection, respectively. The clustering analysis is used to classify different rock types, and the edge detection is used to process the bedding joint information of the working face.

[0045] S3: Perform surrounding rock fissure edge detection on the preprocessed images to obtain the structural plane boundary lines of the images;

[0046] Edge detection: Since the joint or bedding is the fracture of the rock mass of the working face, but there is no significant displacement between the rocks forming the fracture. From the perspective of image analysis, the joint has the following characteristics in the image: the gray value is obviously lower than that of the two side regions, and it is almost black; the geometric characteristics are fine and almost straight line segments of different lengths, but there is no directionality. The image characteristics of the fracture are some polyline segments, and the most obvious feature of the image is a thin black line, which has the characteristic of a gray value obviously lower than that of the two side regions. The local SUSAN operator adopted directly starts from the characteristics of the fracture, and identifies the fracture region. The specific implementation is that a square template of a certain size 9x9 is first selected, the difference between the neighborhood and the reference point is calculated with the center point of the template as the reference point, if the difference is greater than zero, it is set to 1, and if the difference is less than zero, it is set to 0, then the number of 1 is counted as the response output of the center point; finally, the final operator response result image is input after traversing all the points of the image.

[0047] S4, after edge detection, boundary extraction is performed to obtain the information of the bedding and joint of the working face;

[0048] Boundary extraction: due to the edge detection algorithm, there are many discontinuities between the polyline segments of the processed image, so down-sampling combined with Hough transform is used for boundary extraction of the fracture. The purpose of down-sampling is to connect the discontinuous polyline and exclude isolated points. The result after down-sampling.

[0049] The purpose of Hough transform is to detect and extract straight lines. A straight line in an image is a collection of discrete points, and the geometric equation of the discrete points of a straight line can be expressed by a discrete polar coordinate formula of the straight line: X*cos(theta)+y*sin(theta)=r. Where angle theta refers to the included angle between r and the X axis, and r is the geometric perpendicular distance to the straight line. Any point x, y on the straight line can be expressed, where r and theta are constants.

[0050] The pixel coordinates P(x, y) of the image are known, and r and theta are the variables we are looking for. If we can draw each (r, theta) value according to the pixel point coordinate P(x, y) value, then we can convert from the Cartesian coordinate system of the image to the polar coordinate Hough space system. This transformation from point to curve is called Hough transform of straight line. When the Hough transform algorithm starts, each pixel coordinate point P(x, y) is converted to a curve point on (r, theta), and is accumulated to the corresponding grid data point. When a peak appears, it means that there is a straight line, and the information of the fault, bedding, joint, dike, etc. is recorded.

[0051] S5, draw the geological sketch of the current working face combined with the bedding joint information, mainly describe the fault position, occurrence, fault fracture zone width, etc.; mainly describe the joint occurrence, density, width, extension, exposed position, etc.; mainly describe the position, width, fracture, weathering degree of the dike, etc.; mainly describe the position of the water outlet point and its relationship with the fault and joint, water outlet state (drop, flow, gush), water yield, etc. The geological sketch is shown in Figure 1 .

[0052] Step two, based on the geological sketch, combined with the underground cavern excavation and support design drawing, get the surrounding rock fracture and cavern excavation position display diagram, as shown in Figure 1 , through the analysis of the distribution of surrounding rock fractures and field water outlets, determine the fractures that affect the cavern grouting and water plugging, i.e. f3 fractures.

[0053] Step three, as shown in Figure 1 , according to the trend and dip angle of the surrounding rock fractures, determine the drilling hole route K with the highest intersection rate with the surrounding rock fractures;

[0054] This efficient grouting hole layout method is different from the existing vertical hole, as shown in Figure 2 , assuming the hole depth is L, and the intersection length is L0, according to the intersection rate theory, the intersection rate of the hole is: r=L0 / L, where r is the intersection rate, and L0 is the intersection length.

[0055] As shown in Figure 3 , the intersection rate of K4 hole and f4 surrounding rock fracture is r=L4 / L, and the intersection rate of K3 hole and f4 surrounding rock fracture is r=L3 / L. The intersection rate of the grouting hole K4 hole laid according to this efficient grouting hole layout method is much larger than that of the grouting hole K3 hole laid according to the vertical hole method, so the intersection rate of K4 hole is large, the grouting performance is good, and the grouting effect is high, while K3 hole deviates from the fracture direction in the rock mass, and even has no intersection with the fracture in the rock mass, the intersection rate is zero; the vertical hole method cannot achieve the best hole angle, has poor targeting, low intersection rate, low grouting efficiency, large engineering quantity, and high cost.

[0056] The trend of the fractures in the surrounding rock is generally curved in three-dimensional space, rarely extends in a straight line, and the grouting hole direction is a straight line. When underground drilling is performed, the operation space is limited, and it is difficult to realize the combination of hole and fracture. Therefore, the drilling angle must be controlled as much as possible during construction to achieve the maximum intersection rate, improve the grouting effect, and reduce the engineering cost. The center of the grouting hole with the best grouting angle overlaps with the center of the surrounding rock fracture, and the intersection rate with the surrounding rock fracture is the largest; the closer the angle of the grouting hole to the best grouting angle, the better the grouting effect. Therefore, in the process of design or construction, controlling the drilling angle to improve the intersection rate is an important quality index in construction. There are many cases when determining the surrounding rock fractures that affect the cavern excavation through the intersection of surrounding rock fractures and cavern excavation positions:

[0057] Case 1: The analysis of the intersection of the surrounding rock fissure and the position of the chamber excavation determines that the surrounding rock fissure affecting the chamber excavation is a single surrounding rock fissure, which has an intersection with the chamber crown or the excavation face, as shown in the following figure. Figure 4 The specific method is that, according to the principle of determining a straight line by two points, the connecting line of the intersection A of the f1 surrounding rock fissure and the chamber excavation face and the center point B of the f1 surrounding rock fissure is taken as the hole direction to obtain the through-hole K1 with the maximum intersection ratio.

[0058] Case 2: The analysis of the intersection of the surrounding rock fissure and the position of the chamber excavation determines that the surrounding rock fissure affecting the chamber excavation is multiple intersecting surrounding rock fissures, and all the multiple intersecting surrounding rock fissures have an intersection with the chamber crown or the excavation face, as shown in the following figure. Figure 5 The specific method is that, for this case, the highest intersection point of the multiple intersecting surrounding rock fissures, i.e., the intersection D of the f2 surrounding rock fissure and the f3 surrounding rock fissure, and the highest intersection point of the multiple intersecting surrounding rock fissures, i.e., the intersection C of the f3 surrounding rock fissure and the chamber excavation face, are connected as the drilling route to drill the K1 hole, at this time, the intersection ratio of the K1 hole and the f3 surrounding rock fissure is greater than that of the K1 hole and the f1 and f2 surrounding rock fissures, but since the highest intersection point of the surrounding rock fissure and the chamber crown or the excavation face is selected, the operation space is not limited during the underground hole making, and the segment from the intersection E to the intersection D is mostly the post-excavation segment, which is not in the grouting range, so the CFD three-point connecting line is the best grouting arrangement method.

[0059] Case 3: On the basis of Case 2, when the multiple intersecting surrounding rock fissures are roughly parallel and have the same intersection height with the chamber crown and the excavation face, as shown in the following figure. Figure 6 The specific method is that, for this case, the intersection of the surrounding rock fissure and the chamber crown is taken as the hole position, i.e., the intersection F and the intersection C are taken as the hole starting points, respectively, and the intersection G and the intersection D of the f2 surrounding rock fissure are taken as the hole directions, respectively, and then the straight lines FG and CD are connected to drill the K1 and K2 holes, thereby forming the best hole arrangement method.

[0060] Case 4: When the surrounding rock fissure has no intersection with the chamber crown or the excavation face, and there is a risk of water seepage, as shown in the following figure. Figure 7 The specific method is that, for this case, the traditional vertical hole arrangement method is adopted for grouting, because in this case, the hole cannot be arranged along the fissure, and the intersection ratio is the same at any angle.

[0061] The processing methods of the above four cases are applied to the present embodiment, as shown in the following figure. Figure 8As shown, the f1 surrounding rock fissure, the f2 surrounding rock fissure, the f3 surrounding rock fissure and the f4 surrounding rock fissure in the embodiment are the surrounding rock fissures affected by the cavern excavation; therefore, it can be determined that the two drilling routes of the K4 hole and the K1 hole are set, that is, the maximum intersection ratio is obtained, and thus the f1 surrounding rock fissure, the f2 surrounding rock fissure, the f3 surrounding rock fissure and the f4 surrounding rock fissure can be effectively grouted.

[0062] Step four, the drilling rig is positioned to make a hole, and drilling is performed according to the drilling route K; for example, Figure 1

[0063] The grouting hole is usually of a diameter of φ42 mm, and the hole spacing, number and hole depth arrangement thereof are closely related to the distribution, characteristics of the water leakage fissure of the surrounding rock and the grouting pressure and slurry diffusion range, and reasonable hole arrangement is an important factor for obtaining good water plugging effect. In order to achieve an ideal intersection ratio, the main principles are as follows:

[0064] The selection of the grouting hole position should make the bottom of the grouting hole intersect with the water leakage fissure, and be selected at the position with the largest water leakage amount, so as to make the water conductivity good and the water yield large, and almost induce all the water leakage. Generally, the horizontal fissure is suitable for downward inclined hole making along the joint, and the vertical fissure is suitable for straight hole making opposite to the fissure.

[0065] The hole spacing of the grouting hole should be determined according to the water leakage pressure, fissure size, water leakage amount and slurry diffusion radius, and a simulation test can be performed before grouting to determine the hole spacing. When there is no test verification, the hole spacing is generally 100-150 cm. In this example, the grouting is arranged according to a hole spacing of 1.5 m, and the hole spacing can be adjusted according to the effect during the grouting process.

[0066] Step five, grouting is performed through the drilling route with the highest intersection ratio with the surrounding rock fissure;

[0067] Grouting is performed according to the design requirements of the raw materials, grouting mode, grouting pressure, slurry water-cement ratio and the like.

[0068] Step six, water pressure inspection is performed to check the grouting effect, and the geological sketch of the underground cavern design excavation area is obtained again;

[0069] The detailed operation of this step is the same as that of step 1, the actual effect after grouting is checked through the geological sketch of the underground cavern design excavation area obtained again, and if there is still the surrounding rock fissure affected by the cavern excavation, the above steps are repeated for secondary hole arrangement and grouting until the grouting inspection is qualified.

[0070] ​The efficient grouting hole distribution method is suitable for the water plugging operation of the underground cavern grouting in the relatively direct fissure of the surrounding rock, the principle is simple and easy to understand, the operation is convenient, the efficiency is high, the cost can be reduced, and the cost waste caused by the conventional vertical hole system grouting can be avoided. The hole direction is along the joint surface of the surrounding rock and the trend of the fissure and penetrates the joint surface and the trend of the fissure, forms the hole and the crack, realizes the efficient grouting water plugging with few holes. Based on the geological exploration data and the actual situation, the fissure distribution, the water seepage channel, the water seepage amount and the influence range of the surrounding rock in the grouting section are fully investigated, the drill rod is adjusted to the concentric and same direction according to the actual situation during the hole forming. The principle is simple and easy to understand, the operation is convenient, the single hole crack penetration rate is high, the fissure is blocked, the plugging effect is good, the engineering investment can be saved, and the efficient grouting effect is achieved.

[0071] The above embodiments are only used for describing the technical solutions of the present application, but not limited to them; although the present application is described in detail with reference to the above embodiments, those skilled in the art should understand that the technical solutions recorded in the above embodiments can be modified, or some or all of the technical features can be replaced by the equivalent; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application, and they should be covered in the scope of the claims and the description of the present application.

Claims

1. A highly efficient grouting hole distribution method, characterized in that: The efficient grouting hole distribution method is based on the theory of intersection rate, and specifically comprises the following steps: Step one, obtaining a geological sketch of the current tunnel face; Step two, obtaining a surrounding rock fracture and tunnel excavation position intersection graph based on the geological sketch and combined with a tunnel excavation position design graph, and determining the surrounding rock fractures affecting the tunnel excavation through the surrounding rock fracture and tunnel excavation position intersection graph analysis; Step three, determining the drilling hole route with the highest intersection rate with the surrounding rock fractures according to the angle and position of the surrounding rock fractures; Step four, drilling machine in place, drilling according to the drilling hole route to form a grouting hole; Step five, grouting operation through the drilling hole route with the highest intersection rate with the surrounding rock fractures; Step six, obtaining a geological sketch of the designed excavation area of the underground tunnel to check the grouting effect; When the surrounding rock fractures affecting the tunnel excavation are single surrounding rock fractures and the surrounding rock fractures have intersection points with the tunnel crown or excavation face in the step two, the connecting line of the intersection point of the surrounding rock fractures and the tunnel excavation face and the center point of the surrounding rock fractures is taken as the along-joint hole arrangement; When the surrounding rock fractures affecting the tunnel excavation are multiple intersecting surrounding rock fractures and the multiple intersecting surrounding rock fractures all have intersection points with the tunnel crown or excavation face in the step two, the connecting line of the highest intersection point of the multiple intersecting surrounding rock fractures and the highest intersection point of the multiple intersecting surrounding rock fractures is taken as the through hole arrangement; When the surrounding rock fractures affecting the tunnel excavation are multiple intersecting surrounding rock fractures and the multiple intersecting surrounding rock fractures all have intersection points with the tunnel crown or excavation face in the step two, and the intersection points of the multiple intersecting surrounding rock fractures and the tunnel crown and excavation face are at the same height, the intersection point of the surrounding rock fractures and the tunnel crown is selected as the parallel hole arrangement; When the surrounding rock fractures affecting the tunnel excavation have no intersection points with the tunnel crown or excavation face and there is a risk of water seepage in the step two, the vertical hole arrangement is adopted; The calculation method of the intersection rate is as follows: r=L0 / L In the formula, L is the hole depth, L0 is the intersection length, and r is the intersection rate.

2. The efficient grouting hole distribution method according to claim 1, characterized in that: The geological sketch is obtained in the following manner: S1, infrared camera shooting to obtain a tunnel face image of the current tunnel section; S2, image preprocessing of the obtained tunnel face image; S3, surrounding rock fracture edge detection of the preprocessed image to obtain an image structure surface boundary line; S4, boundary extraction after edge detection to obtain bedding joint information of the tunnel face; S5, drawing a geological sketch of the current tunnel face combined with the bedding joint information, and marking the in-rock joint and fracture trend.

3. The efficient grout placement hole delivery method of claim 1, wherein: The grouting hole adopts a hole diameter of φ42mm, and the hole spacing, number and hole depth arrangement are determined according to the distribution and characteristics of the water leakage fractures of the surrounding rock, and the grouting pressure and slurry diffusion range.

4. The method of claim 3, wherein: The selection of the position of the grouting hole should make the bottom of the grouting hole intersect with the water leakage fracture, and be selected at the position with the largest water leakage amount. The horizontal fracture is preferably inclined upward along the fracture, and the vertical fracture is preferably perpendicular to the fracture.

5. The method of claim 3, wherein: The hole distance of the grouting hole should be determined according to the water leakage pressure, the fracture size, the water leakage amount and the diffusion radius of the slurry, and a simulation test is performed before grouting, and the interval distance is adjusted according to the effect during the grouting process.

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