Ultra-high-strength integrated anchor-grouting support device and support method

Abstract

The present invention discloses an ultra-high-strength integrated anchor-grouting support device and a support method, and relates to the technical field of surrounding rock control of coal mine tunnels. The device comprises: a grouting tray, a hemispherical groove is provided at the center of the grouting tray, a conical step is provided at the bottom of the hemispherical groove, a plurality of grouting holes are provided in the conical step, and a grouting steel pipe is installed in the grouting hole; a self-aligning ball head, the self-aligning ball head is matched with the groove of the grouting tray and can rotate freely, the self-aligning ball head is provided with a drilling hole, an annular grouting groove is provided on the peripheral side of the self-aligning ball head, and a plurality of grouting holes are provided in the annular grouting groove; a grouting steel pipe, one end of the grouting steel pipe is fixedly connected to the self-aligning ball head, and the peripheral side of the grouting steel pipe is densely covered with through holes; a grouting connection device, which is connected to the grouting steel pipe when grouting is performed; an anchor rod vertically inserted into the grouting steel pipe, and the anchor rod passes through a sealing plug. The present invention has the advantages of large flow, adjustable centering, and easy construction, and can effectively improve the grouting efficiency of the solid anchor rod and the strength and effect of anchor-grouting support.

Description

Technical Field

[0001] The invention belongs to the technical field of surrounding rock control of coal mine tunnels, and in particular relates to an ultra-high-strength integrated anchor-grouting support device and a support method. Background Art

[0002] In the field of surrounding rock control of coal mine tunnels, the combination of grouting reinforcement technology and anchor bolt and cable support technology to form "anchor grouting" support technology is a widely used means of surrounding rock control for complex conditions tunnels. It can significantly improve the bearing capacity of surrounding rocks and the anchoring performance of anchor bolts and cables. It is a key technology to achieve safe control of surrounding rocks in complex conditions tunnels and ensure safe, efficient and green mining of coal resources. At present, the high-strength anchor grouting support method with "hollow grouting anchor cable or hollow grouting anchor rod" as the core is widely used in actual engineering, such as Chinese patent ZL200920226255.4, railway industry standard TB / T3356-2014, etc. It mainly uses the hollow structure of the anchor cable (rod) body for grouting to achieve full-length anchoring of the anchor cable (rod) and cementation reinforcement of surrounding rock cracks. However, since the ultimate bearing capacity of the hollow grouting anchor cable (rod) is significantly lower than that of the solid anchor cable (rod) under the same diameter conditions, the existing high-strength anchor grouting support technology is difficult to meet the actual underground complex conditions tunnel support strength requirements. How to use the original solid anchor cables (rods) for surrounding rock grouting reinforcement, so as to achieve both surrounding rock strengthening and full-length anchoring of the anchor cables (rods), and thus achieve an ultra-high-strength integrated anchor-grouting support effect that exceeds the existing anchor-grouting support strength, is a current research hotspot in the fields of mining engineering and geotechnical engineering.

[0003] Chinese patents 2019212039250, 202211316440.9, etc. propose a device and method for grouting using a solid anchor rod (cable), but this type of technology generally has the following problems during use:

[0004] (1) Due to the limited size of the slurry inlet hole, the slurry injection speed is slow and the grouting efficiency is low. At the same time, impurities such as large particles in the slurry will cause the slurry inlet hole to be blocked, resulting in grouting failure.

[0005] (2) When the anchor cable (rod) borehole is not perpendicular to the tunnel surface (i.e., inclined borehole), it is difficult to install the grouting device to fit tightly to the rock surface. On the one hand, this will cause the grouting device to be damaged by shearing, and on the other hand, the borehole will not be able to be sealed tightly, resulting in serious slurry leakage.

[0006] Therefore, the existing devices and methods for grouting using solid anchor cables (rods) still have a lot of room for improvement in the application of complex tunnel conditions in coal mines. In order to meet the needs of ultra-high-strength anchor support in complex tunnel conditions, it is urgent to invent a multifunctional and efficient grouting device and anchor support method that can be used for solid anchor cable (rod) grouting with large flow, adjustable centering, and easy construction. Summary of the invention

[0007] The purpose of the present invention is to provide an ultra-high strength integrated anchor grouting support device and a support method, which has the advantages of large flow, adjustable centering, easy construction, etc., and can effectively improve the grouting efficiency of solid anchor cables (rods) and the strength and effect of anchor grouting support.

[0008] In order to solve the above technical problems, the present invention is achieved through the following technical solutions:

[0009] The present invention is an ultra-high strength integrated anchor-grouting support device, comprising:

[0010] A grouting tray, wherein the center of the grouting tray is provided with a through hemispherical groove, the bottom circumference of the hemispherical groove is provided with a conical step, a plurality of grouting holes are evenly arranged in the conical step, and a grouting steel pipe is installed in the grouting hole;

[0011] A self-aligning ball head, which is hemispherical and fits the groove of the grouting tray and can rotate freely. The self-aligning ball head is provided with a drill hole. The circumference of the self-aligning ball head is provided with an annular grouting groove opposite to the position of the conical step, and a plurality of grouting holes are provided in the annular grouting groove;

[0012] A grouting steel pipe, one end of which is fixedly connected to the self-aligning ball head, and the circumference of the grouting steel pipe is densely covered with through holes;

[0013] A grouting connection device, which is connected to the grouting steel pipe during grouting;

[0014] An anchor rod is vertically inserted into the grouting steel pipe from the entrance of the self-aligning ball head, and a sealing plug is provided at the entrance of the drill hole of the self-aligning ball head, and the anchor rod passes through the sealing plug.

[0015] As a preferred technical solution of the present invention, the grouting tray is a square thick steel plate, and the thickness of the grouting tray is not less than 20 mm.

[0016] As a preferred technical solution of the present invention, the angle of the tapered step is 30-45°.

[0017] As a preferred technical solution of the present invention, there are four slurry inlet holes, all of which are perpendicular to the side direction of the grouting tray and penetrate the hemispherical groove. An internal thread is provided at the entrance of the slurry inlet hole.

[0018] As a preferred technical solution of the present invention, the slurry inlet steel pipe is L-shaped, and one end is threadedly connected to the slurry inlet hole, and the other end is provided with an internal thread, which is used to install a sealing rod when spraying on the tunnel surface.

[0019] As a preferred technical solution of the present invention, two parallel annular sealing grooves with sealing rubber rings are provided in the hemispherical groove; and they are respectively located above and below the pulp inlet hole.

[0020] As a preferred technical solution of the present invention, a conical drilling plug is sleeved on the grouting steel pipe.

[0021] As a preferred technical solution of the present invention, the grouting connection device includes: a slurry storage bin, one end of which is connected to a slurry inlet hose, and the other end is provided with a plurality of slurry outlet hoses, the slurry inlet hose is provided with a stop valve, and the slurry outlet hose is connected to the slurry inlet steel pipe during grouting.

[0022] The present invention also provides a support method, which adopts the above-mentioned ultra-high strength integrated anchor-grouting support device, and the method comprises the following steps:

[0023] To install the solid anchor, a hydraulic anchor drill is used to drill a large hole in the tunnel, and then a small hole is drilled at the end of the large hole. One end of the solid anchor is grout-fixed at the bottom of the small hole, and finally the grouting steel pipe is installed in the large hole.

[0024] Install the grouting tray, put the drilling plug, the steel plate for tunnel support, and the grouting tray on the grouting steel pipe in sequence, and the outlet of the grouting steel pipe on the grouting tray should face the tunnel space; then connect the self-aligning ball head to the grouting steel pipe through threads, install the sealing plug and the anchor nut, and perform anchor pre-tensioning;

[0025] The tunnel surface is sprayed and sealed. After the grouting tray is installed, the tunnel surface is sprayed with concrete to seal it. When spraying concrete, a solid sealing stick is first installed at the entrance of the slurry steel pipe. One end of the sealing stick is provided with an external thread, which can be connected to the outlet thread of the slurry steel pipe. The length is greater than the thickness of the sprayed concrete layer. When the tunnel surface is sprayed with concrete, the sealing stick is removed from the grouting tray.

[0026] For grouting of solid anchor rods, connect the outlet hose of the grouting connection device to the grouting steel pipe of the grouting tray through the reserved drilled hole in the shotcrete layer, connect the grouting pump output pipeline to the grouting hose of the grouting connection device, open the stop valve, and then grout the solid anchor rods.

[0027] The present invention has the following beneficial effects:

[0028] 1. The grouting tray has both the supporting function of a conventional tray and the grouting function, effectively realizing the integration of solid anchor cable (rod) support and grouting.

[0029] 2. The grouting tray has multiple grouting channels with large diameters, which significantly increases the grouting volume and speed during the grouting process and prevents grouting channels from being blocked;

[0030] 3. The self-aligning ball head allows the grouting steel pipe and the solid anchor cable (rod) to rotate freely within a certain range, solving the problem that conventional grouting devices cannot be used for inclined drilling. It can not only ensure the sealing effect of drilling grouting, but also prevent the grouting steel pipe and the anchor cable from being sheared.

[0031] Of course, any product implementing the present invention does not necessarily need to achieve all of the advantages described above at the same time. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for describing the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative work.

[0033] Figure 1 It is the installation schematic diagram of the present invention.

[0034] Figure 2 It is a top view of the grouting tray in the present invention.

[0035] Figure 3 It is a schematic diagram of the three-dimensional structure of the self-aligning ball head in the present invention.

[0036] Figure 4 It is a schematic structural diagram of the grouting connection device in the present invention.

[0037] In the accompanying drawings, the components represented by the reference numerals are listed as follows:

[0038] 1-anchor rod; 2-grouting steel pipe; 21-through hole; 3-grouting tray; 31-slurry inlet hole; 32-sealing rubber ring; 33-conical step; 4-self-aligning ball head; 41-annular slurry outlet groove; 42-slurry outlet hole; 5-drilling plug; 6-steel guard plate; 7-slurry inlet steel pipe; 8-sealing plug; 9-anchor rod nut; 10-large hole; 11-small hole; 12-slurry storage bin; 13-slurry inlet hose; 14-slurry outlet hose; 15-stop valve. DETAILED DESCRIPTION

[0039] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0040] In the description of the present invention, it should be understood that the terms "opening", "upper", "lower", "thickness", "top", "middle", "length", "inside", "all around" and the like indicating orientation or positional relationship are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the components or elements referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0041] See also Figure 1-Figure 4 The present invention discloses an ultra-high-strength integrated anchor-grouting support device, comprising a grouting tray 3, a self-aligning ball head 4, a grouting steel pipe 2, a grouting connection device, and an anchor rod 1.

[0042] A specific application of this embodiment is: the ultra-high strength integrated anchor-grouting support device is mainly composed of the following parts:

[0043] 1. Grouting tray 3

[0044] The grouting tray 3 is made by cutting a square thick steel plate with a thickness of not less than 20 mm; a hemispherical groove is opened in the center of the grouting tray 3, and the hemispherical groove runs through the grouting tray 3; from the side with a smaller diameter of the hemispherical groove opening on the surface of the grouting tray 3, a hole is expanded toward the inside of the tray to form a conical step 33 with an angle of about 30-45°, and the depth of the conical step 33 is about 1 / 5 of the thickness of the grouting tray 3;

[0045] A circular slurry inlet hole 31 is opened on each of the four sides of the grouting tray 3. The four slurry inlet holes 31 are perpendicular to the side direction of the grouting tray 3 and are connected with the hemispherical groove; a threaded internal thread is provided at the entrance of each slurry inlet hole 31, and four "L-shaped" slurry inlet steel pipes 7 are installed respectively, and the outer diameter of the slurry inlet steel pipe 7 is smaller than the thickness of the grouting tray 3; one end of the "L-shaped" slurry inlet steel pipe 7 is provided with a threaded external thread (connected to the slurry inlet hole 31), and the other end is provided with a threaded internal thread; after the "L-shaped" slurry inlet steel pipe 7 is threadedly connected and fixed with the slurry inlet hole 31, the slurry inlet steel pipe 7 and the surface of the grouting tray 3 are kept in a vertical state;

[0046] Two annular sealing grooves with a groove width of 1 mm are arranged in the hemispherical groove; the two annular sealing grooves are respectively located above and below the slurry inlet hole 31; and two sealing rubber rings 32 are respectively arranged in the annular sealing grooves.

[0047] 2. Self-aligning ball head 4

[0048] The self-aligning ball head 4 is made of the same steel material as the grouting tray 3 and is made into a hemispherical shape. The spherical surface is completely consistent with the spherical surface of the hemispherical groove in the grouting tray 3, but the height of the self-aligning ball head 4 is greater than the depth of the hemispherical groove; the self-aligning ball head 4 can rotate freely in the hemispherical groove of the grouting tray 3;

[0049] A through hole is opened at the center of the plane of the vertical self-aligning ball head 4, and the diameter of the hole is larger than the diameter of the anchor rod 1 to ensure that the anchor rod 1 can freely pass through the hole; a certain length of threaded internal thread is opened at the exit of the hole for connecting the grouting steel pipe 2;

[0050] An annular slurry outlet groove 41 is opened in the middle of the hemispherical surface of the self-aligning ball head 4, the groove depth is about 1 / 4~1 / 3 of the radius of the self-aligning ball head 4, and the groove width is smaller than the distance between the two annular sealing grooves in the upper hemispherical groove of the grouting tray 3; four slurry outlet holes 42 are opened at the bottom of the annular slurry outlet groove 41, and the slurry outlet holes 42 are evenly distributed; the depth of the annular slurry outlet groove and the number of slurry outlet holes 42 can be increased according to the grouting flow rate requirements.

[0051] A conical sealing plug 8 is provided at the entrance of the borehole of the self-aligning ball head 4, with an inner diameter slightly larger than the diameter of the anchor rod and a thickness not exceeding 20 mm, to prevent slurry from flowing out of the gap between the borehole of the self-aligning ball head 4 and the anchor rod.

[0052] 3. Grouting steel pipe 2

[0053] The grouting steel pipe 2 is made of a seamed or seamless grouting steel pipe, the outer diameter of the grouting steel pipe 7 is 32-36 mm, and the wall thickness is not less than 1 mm; an outer thread is arranged at one end of the grouting steel pipe 2, which can match and connect with the inner thread of the drill hole outlet of the self-aligning ball head 4; a drilling plug 5 is sleeved on the grouting steel pipe 2, which is made of flexible rubber, is conical, and has a length of not less than 300 mm;

[0054] The grouting steel pipe 2 is drilled with through holes 21 in sequence; the length of the grouting steel pipe 2 is determined according to the grouting depth required by the anchor rod. When the grouting depth exceeds 3000mm, the grouting steel pipe 2 is connected in sections of 1500~2000mm.

[0055] 4. Grouting connection device

[0056] The grouting connection device includes a slurry inlet hose 13, four slurry outlet hoses 14, a slurry storage bin 12, and a stop valve 15; the slurry storage bin is disc-shaped, with a slurry inlet internal threaded opening and four slurry outlet internal threaded openings arranged around it, and the stop valve 15 is connected to the slurry inlet internal threaded opening; the diameter of the slurry inlet hose is larger than that of the slurry outlet hose, and the cross-sectional area is 4 times that of the slurry outlet hose.

[0057] One end of the slurry inlet hose 13 is connected to the stop valve 15 at the slurry inlet internal threaded port of the slurry storage bin 12, and the other end is provided with a universal quick-connect connector for connecting to the grouting pump output pipeline;

[0058] Both ends of the slurry discharge hose 14 are provided with external thread, one end is respectively connected to the four slurry discharge internal thread ports, and the other end is respectively connected to the four "L-shaped" slurry inlet steel pipes 7 of the grouting tray 3.

[0059] The support method using the above-mentioned ultra-high strength anchor-grouting support device is as follows:

[0060] 1. Install the solid anchor rod. According to the design requirements of the tunnel anchor support, select the appropriate position of the tunnel roof or the two sides, use a hydraulic anchor drill to drill a large hole 10 with a hole diameter of φ32~42mm, and the drilling depth is slightly greater than the designed grouting depth requirement; then use a hydraulic anchor drill to drill a small hole 11 with a hole diameter of φ28~32mm, and the total depth (depth of the large hole 10 + depth of the small hole 11) meets the designed solid anchor rod length requirement. After the hole is drilled, first put the grouting steel pipe 2 into the large hole 10, then put a specified amount of resin anchoring agent into the grouting steel pipe 2, use the anchor rod to send the resin anchoring agent to the bottom of the small hole 11, and use the anchor drill to fully stir it, so that the solid anchor rod is effectively anchored at the bottom of the small hole 11. In this step, by first putting the grouting steel pipe 2 into the large hole 10, the "step effect" between the "large hole 10" and the "small hole 11" can be eliminated, so that the resin anchoring agent can be smoothly sent into the small hole 11.

[0061] 2. Install the grouting tray 3. Put the drilling plug 5, the steel guard plate 6 or W-shaped / M-shaped steel belt for roadway support, and the grouting tray 3 on the grouting steel pipe 2 in sequence, and the outlet of the "L-shaped" grouting steel pipe 7 on the grouting tray 3 should face the roadway space; then connect the self-aligning ball head 4 to the grouting steel pipe 2 through threads, and then put the conical sealing plug 8 on the anchor rod 1, and finally install the anchor cable lock or anchor rod nut 9, and pre-tension the anchor rod. In this step, the grouting tray 3 is used in conjunction with the steel guard plate or W-shaped / M-shaped steel belt for tunnel support to achieve a better surface protection support effect than the conventional anchor tray, so the conventional anchor tray in the previous support can be eliminated; at the same time, the grouting tray 3 can be used to achieve direct grouting of the solid anchor; in addition, since the self-aligning ball head 4 can achieve 30~45° free rotation, when the drill hole is not perpendicular to the tunnel surface, the self-aligning ball head 4 can be rotated to achieve a close fit between the tray and the tunnel surface, which can not only ensure the sealing effect of the drilling grouting, but also prevent the grouting steel pipe 2 and the anchor body from being sheared.

[0062] 3. Spray grouting and sealing of the tunnel surface. After the grouting tray 3 is installed, the tunnel surface needs to be sealed with sprayed concrete to prevent grouting and leakage from the surrounding rock surface during the subsequent grouting process. When spraying concrete, in order to prevent the sprayed concrete from covering the outlet of the grouting steel pipe 7 on the grouting tray 3, a solid PVC sealing stick is installed at the outlet of each grouting steel pipe 7. One end of the sealing stick is provided with an external thread, which can be connected to the outlet thread of the grouting steel pipe 7. The diameter of the sealing stick is slightly larger than the diameter of the grouting hose 14, and the length is greater than the thickness of the sprayed concrete layer. The sealing stick is installed on each grouting tray 3 before spraying concrete. After the spraying of concrete on the tunnel surface is completed, it is promptly removed from the grouting tray 3 for reuse; corresponding holes will be left in the sprayed concrete layer at the sealing stick for the subsequent installation of the grouting hose 14 of the grouting connection device.

[0063] 4. Grouting of solid anchor rods. Connect the four grouting hoses 14 of the grouting connection device to the four grouting steel pipes 7 of the grouting tray 3 through the reserved holes in the shotcrete layer in turn, connect the grouting pump output pipeline to the grouting hose 13 of the grouting connection device, and open the stop valve 15 to grout the solid anchor rod. When the grouting of the anchor rod is completed, close the stop valve 15. After waiting for a few minutes (after the drilling and pipeline grouting pressure dissipates), take out the four grouting hoses of the grouting connection device from the grouting tray 3 in turn for reuse in subsequent grouting. In this step, the slurry flow process is: grouting pump → grouting connection device grouting hose 13 → grouting connection device 4-way grouting hose 14 → 4 grouting steel pipes 7 on the grouting tray 3 → 4 grouting holes 31 on the grouting tray 3 → annular grouting groove 41 on the self-aligning ball head 4 → grouting hole 42 of the self-aligning ball head 4 → grouting steel pipe 2 → through hole 21 of grouting steel pipe 2 → surrounding rock drilling. Compared with the previous grouting device, by increasing the channel for slurry injection into the borehole, the grouting amount and grouting speed are significantly improved, and the grouting efficiency is improved. At the same time, the grouting connection device can be reused, reducing the cost of auxiliary grouting materials.

[0064] In the description of this specification, the description with reference to the terms "one embodiment", "example", "specific example", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0065] The preferred embodiments of the present invention disclosed above are only used to help illustrate the present invention. The preferred embodiments do not describe all the details in detail, nor do they limit the invention to the specific implementation methods described. Obviously, many modifications and changes can be made according to the content of this specification. This specification selects and specifically describes these embodiments in order to better explain the principles and practical applications of the present invention, so that those skilled in the art can understand and use the present invention well. The present invention is limited only by the claims and their full scope and equivalents.

Claims

1. Ultra-high strength integrated anchor grouting support device, characterized in that: include: A grouting tray, the center of which is provided with a through hemispherical groove, the bottom of which extends from the side with a smaller hole diameter to the inside of the tray to form a conical step, a plurality of slurry inlet holes are evenly arranged in the conical step, and a slurry inlet steel pipe is installed at the entrance of the slurry inlet hole; A self-aligning ball head, which is hemispherical and fits into a hemispherical groove to rotate freely. The self-aligning ball head is provided with a drill hole. The circumference of the self-aligning ball head is provided with an annular slurry outlet groove opposite to the position of the conical step, and a plurality of slurry outlet holes are provided in the annular slurry outlet groove; A grouting steel pipe, one end of which is fixedly connected to the self-aligning ball head, and the circumference of the grouting steel pipe is densely covered with through holes; A grouting connection device, which is connected to the grouting steel pipe during grouting; An anchor rod is vertically inserted into the grouting steel pipe from the entrance of the self-aligning ball head. A sealing plug is provided at the entrance of the drill hole of the self-aligning ball head, and the anchor rod passes through the sealing plug.

2. The ultra-high strength integrated anchor-grouting support device according to claim 1 is characterized in that: The grouting tray is a square thick steel plate, and the thickness of the grouting tray is not less than 20 mm.

3. The ultra-high strength integrated anchor-grouting support device according to claim 1 is characterized in that: The angle of the tapered step is 30-45°.

4. The ultra-high strength integrated anchor-grouting support device according to claim 1 is characterized in that: There are four slurry inlet holes, all of which are perpendicular to the side direction of the grouting tray and penetrate the hemispherical groove. The entrances of the slurry inlet holes are provided with internal threads.

5. The ultra-high strength integrated anchor-grouting support device according to claim 1 is characterized in that: Two parallel annular sealing grooves with sealing rubber rings are arranged in the hemispherical groove, and are respectively located above and below the pulp inlet hole.

6. The ultra-high strength integrated anchor-grouting support device according to claim 1, characterized in that: The slurry inlet steel pipe is L-shaped, and one end is threadedly connected to the slurry inlet hole, and the other end is provided with an internal thread, which is used to install a sealing rod when spraying slurry on the tunnel surface.

7. The ultra-high strength integrated anchor-grouting support device according to claim 6, characterized in that: A conical drilling hole sealing plug is sleeved on the grouting steel pipe.

8. The ultra-high strength integrated anchor-grouting support device according to claim 7 is characterized in that: The grouting connection device comprises: a slurry storage bin, one end of which is connected to a slurry inlet hose, and the other end is provided with a plurality of slurry outlet hoses, the slurry inlet hose is provided with a stop valve, and the slurry outlet hose is connected to the slurry inlet steel pipe during grouting.

9. A support method using the ultra-high strength integrated anchor-grouting support device according to claim 8, characterized in that: The method comprises the following steps: To install the anchor rod, a hydraulic anchor drill is used to drill a large hole in the tunnel, and then a small hole is drilled at the end of the large hole. One end of the anchor rod is fixed at the bottom of the small hole, and finally the grouting steel pipe is installed in the large hole. Install the grouting tray, put the drilling plug, the steel plate for tunnel support, and the grouting tray on the grouting steel pipe in sequence, and the outlet of the grouting steel pipe on the grouting tray should face the tunnel space; then connect the self-aligning ball head to the grouting steel pipe through threads, install the sealing plug and the anchor nut, and perform anchor pre-tensioning; The tunnel surface is sprayed and sealed. After the grouting tray is installed, the tunnel surface is sprayed with concrete to seal it. When spraying concrete, a solid sealing stick is first installed at the entrance of the slurry steel pipe. One end of the sealing stick is provided with an external thread, which can be connected with the outlet thread of the slurry steel pipe. The length is greater than the thickness of the sprayed concrete layer. When the tunnel surface is sprayed with concrete, the sealing stick is removed from the grouting tray. For anchor grouting, connect the grouting hose of the grouting connection device to the grouting steel pipe of the grouting tray through the reserved drilled hole in the shotcrete layer, connect the grouting pump output pipeline to the grouting hose of the grouting connection device, open the stop valve, and grout the anchor.

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