Advanced pipe shed high pressure control grouting device and method

Abstract

The application relates to the technical field of tunnel construction, in particular to an advanced pipe shed high-pressure control grouting device and method. The advanced pipe shed high-pressure control grouting device comprises a grouting pipe shed, a grout stopping device and a grout stopping grouting pipe. The grout stopping device is a membrane bag woven by fiber cloth, the grout stopping device is wrapped around the periphery of at least part of the pipe section of the grouting pipe shed, and the length of the grout stopping device along the length direction of the grouting pipe shed is greater than the thickness of the pipe shed guide wall, so that the grout stopping device can partially extend into the surrounding rock borehole through the pipe shed guide wall; the grout stopping grouting pipe is connected with the grout stopping device and is used for injecting grout into the grout stopping device, so that the injected grout extrudes the rock wall of the surrounding rock borehole to play a grout stopping role. In this way, the pressure of grouting on the grouting pipe shed can be improved, high-pressure grouting is realized, the grouting pipe shed can be fully coupled with the rock wall of the surrounding rock borehole, the combination strength of the grouting pipe shed and the surrounding rock is improved, the purpose of pre-reinforcing the surrounding rock is achieved, the construction is simple and fast, and the safety is high.

Description

Technical Field

[0001] The present application relates to the technical field of tunnel construction, and in particular to an advanced pipe-roof high-pressure controlled grouting device and method. Background Art

[0002] During tunnel construction, many processes require advance grouting reinforcement to ensure construction quality and safety. Taking tunnel entrances and exits as an example, during tunnel excavation, the surrounding rock stability of the portal section is relatively poor. Pipe-roof support can be pre-installed within a certain range outside the tunnel excavation contour to form an advance support structure. This advance support structure provides support in the strata ahead of the tunnel excavation face and can effectively control surrounding rock deformation. Especially in weak and fractured strata, such as soil tunnels or rock tunnel entrances with developed joints and fissures, pipe-roof support can withstand pressure from the soil or rock above and to the sides, preventing premature collapse of the surrounding rock during excavation.

[0003] For shallow tunnel entrances, pipe-roof support can enhance the bearing capacity of the ground at the top of the tunnel, avoiding excessive surface settlement due to a thin cover layer during construction. Conventional tunnel entrance pipe-roof support generally uses a large pipe-roof with a drilling depth greater than 30 meters for super-strength reinforcement. First, the tunnel entrance is excavated, a guide wall is constructed, and a guide steel pipe is installed on the guide wall. A down-the-hole drill is used to drill a hole through the guide steel pipe, and then the pipe-roof is inserted into the drill hole, and then low-pressure grouting is performed on the pipe-roof. The specific problems with the existing advanced pipe-roof grouting construction method are as follows:

[0004] (1) Due to the small spacing between the pipe racks and the impact of the down-the-hole drill during the drilling process, the integrity of the surrounding rock is easily damaged;

[0005] (2) Due to the low grouting pressure for the pipe roof, it is impossible to achieve full coupling between the grouting pipe roof and the borehole wall, which easily leads to separation of the pipe roof and the surrounding rock, overall destruction of the surrounding rock, and intrusion limit of about 10 meters.

[0006] (3) The above problems can be remedied by increasing the density of small advance guide tubes and conducting partial excavation. However, temporary upward excavation and large drill angles are prone to fatigue, which can easily have a serious impact on construction progress, quality and safety. Summary of the Invention

[0007] In order to solve the above technical problems or at least partially solve the above technical problems, the present application provides an advanced pipe-roof high-pressure controlled grouting device and method.

[0008] The first aspect of the present application provides an advanced pipe-roof high-pressure controlled grouting device, comprising:

[0009] A grouting pipe rack, wherein a grouting port is formed at one end of the grouting pipe rack along the length direction, the grouting pipe rack comprises a first pipe section relatively close to the grouting port and a second pipe section relatively far from the grouting port, and a plurality of slurry outlet holes are spaced apart on the pipe wall of the second pipe section;

[0010] A grouting device, the grouting device being a membrane bag woven from fiber cloth, the grouting device being wrapped around the periphery of at least a portion of the first pipe section of the grouting pipe rack, and the length of the grouting device along the length direction of the grouting pipe rack being greater than the thickness of the pipe rack guide wall, so that the grouting device can partially extend into the surrounding rock borehole through the pipe rack guide wall;

[0011] A grouting pipe is connected to the grouting device and is used to inject slurry into the grouting device so that the injected slurry squeezes the rock wall of the surrounding rock borehole to play a grouting role.

[0012] In some embodiments, the difference between the length of the grouting stop device along the length direction of the grouting pipe shed and the thickness of the pipe shed guide wall is greater than or equal to 1.5 meters;

[0013] Alternatively, along the length direction of the grouting pipe rack, the distances between the plurality of grouting holes and the grouting port are all greater than or equal to 2.5 meters.

[0014] In some embodiments, the grouting stop device has a accommodating cavity arranged around the grouting pipe rack, and the grouting stop device is sealed at both ends along the length direction. The grouting stop grouting pipe is connected to one end of the grouting stop device relatively close to the grouting port and is connected to the accommodating cavity to inject slurry into the accommodating cavity.

[0015] In some embodiments, the grouting device includes a first grouting section and a second grouting section that are interconnected along the length direction, and the grouting pipe is connected to the first grouting section;

[0016] A guide steel pipe for the grouting pipe rack to pass through is provided on the pipe rack guide wall, the second grouting stop section extends into the surrounding rock borehole through the guide steel pipe, the first grouting stop section is located at the guide steel pipe, the first grouting stop section is used to squeeze the guide steel pipe to stop grouting when slurry is injected, and the second grouting stop section is used to squeeze the rock wall of the surrounding rock borehole to stop grouting when slurry is injected.

[0017] In some embodiments, the plurality of slurry outlets are arranged in a plum blossom shape on the wall of the grouting pipe shed, and the directions of the slurry outlets can be adjusted by rotating the grouting pipe shed so that the directions of the plurality of slurry outlets are staggered from the top area of ​​the grouting pipe shed;

[0018] And / or, the grouting pipe rack has an opening that is cut obliquely and opened at one end thereof that is relatively far away from the grouting port along the length direction.

[0019] A second aspect of the present application provides a method for high-pressure controlled grouting of an advanced pipe roof, using the high-pressure controlled grouting device of any of the above embodiments, the method comprising the following steps:

[0020] S1: After the excavation of the opening protection is completed, the pipe roof guide wall is constructed;

[0021] S2, drilling holes into the surrounding rock around the cave entrance using drilling equipment;

[0022] S3, before installing the grouting pipe shed, prepare a grouting stop device, wherein the grouting stop device is a membrane bag woven from fiber cloth, and wrap the grouting stop device around the periphery of a portion of the pipe section of the grouting pipe shed to be installed, wherein the length of the grouting stop device along the longitudinal direction of the grouting pipe shed is greater than the thickness of the guide wall of the grouting pipe shed, and connect the grouting stop grouting pipe to the grouting stop device;

[0023] S4, extending the grouting pipe rack equipped with the grouting stop device into the surrounding rock drill hole through the pipe rack guide wall, and ensuring that the length of the grouting stop device extending through the pipe rack guide wall into the surrounding rock drill hole is greater than or equal to a preset length value;

[0024] S5, grouting is performed on the grouting device through the grouting stop grouting pipe, and after the slurry solidifies and reaches a preset strength value, high-pressure controlled grouting is performed on the grouting pipe rack.

[0025] In some embodiments, in S2, the drilling equipment uses a rotary geological drill or a rotary percussion drill; or, the drilling equipment uses a down-the-hole drill, and each time a first preset length is drilled, a second preset length is overlapped to ensure the drilling direction.

[0026] In some embodiments, in S3, the length of the grouting stop device along the length direction of the grouting pipe shed is lengthened to increase the length of the grouting stop device extending into the surrounding rock borehole through the pipe shed guide wall along the length direction of the grouting pipe shed, so as to suppress slurry from overflowing the surface;

[0027] Alternatively, in S4, the directions of the plurality of slurry outlet holes on the grouting pipe roof are adjusted by rotating the grouting pipe roof so that the directions of the plurality of slurry outlet holes are staggered from the top area of ​​the grouting pipe roof to prevent the slurry from overflowing onto the ground.

[0028] In some embodiments, in S4, the grouting pipe rack is installed by adding two guide chains; and / or, an oblique opening is set at the pipe opening at one end of the grouting pipe rack away from the grouting port to optimize the installation of the grouting pipe rack.

[0029] In some embodiments, in S5, the grouting condition is continuously observed during the high-pressure controlled grouting of the grouting pipe rack. If overflow occurs, any one or a combination of the gel time, the grouting pressure, and the water-to-material ratio of the slurry is adjusted to adjust the diffusion radius of the slurry.

[0030] Wherein, the grouting pressure of the high-pressure controlled grouting of the grouting pipe rack is greater than or equal to 2.5 MPa and less than or equal to 7.5 MPa.

[0031] The technical solution provided by the embodiments of the present application has the following advantages compared with the prior art:

[0032] The advanced pipe-roof high-pressure controlled grouting device and method provided in the present application wrap a special grouting-stopping device on the grouting pipe-roof. The grouting-stopping device is specifically a membrane bag woven with fiber cloth, and the length of the grouting-stopping device along the length direction of the grouting pipe-roof is greater than the thickness of the pipe-roof guide wall, and a grouting-stopping grouting pipe is connected to the grouting-stopping device. With such an arrangement, when the pipe-roof is installed, the grouting pipe-roof wrapped with the grouting-stopping device can be extended into the surrounding rock borehole through the pipe-roof guide wall, and the grouting-stopping device can be partially extended into the surrounding rock borehole through the pipe-roof guide wall, and then slurry is injected into the grouting-stopping device through the grouting-stopping grouting pipe, and the injected slurry is used to squeeze the rock wall of the surrounding rock borehole to stop grouting. The utility model discloses that when grouting the grouting pipe roof is carried out subsequently, the grouting stop device can be used to prevent the slurry from seeping out, so that the grouting pressure can be increased during the subsequent grouting of the grouting pipe roof, and high-pressure grouting can be achieved, so that the grouting pipe roof can be fully coupled with the rock wall of the surrounding rock borehole, thereby improving the bonding strength between the grouting pipe roof and the surrounding rock, and realizing the consolidation of the surrounding rock between the pipe roofs, thereby achieving the purpose of pre-reinforcement of the surrounding rock and reducing the influence of the overall destruction of the surrounding rock caused by the drilling process; and the construction of wrapping the grouting device on the grouting pipe roof and grouting the grouting device is simple, the construction speed is fast, which is conducive to improving the construction quality and has high construction safety. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application.

[0034] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0035] Figure 1 A schematic diagram of the structure of the advanced pipe-roof high-pressure controlled grouting device provided in an embodiment of the present application;

[0036] Figure 2Schematic diagram of high-pressure controlled grouting performed by the advanced pipe-roof high-pressure controlled grouting device provided in an embodiment of the present application;

[0037] Figure 3 A schematic flow chart of the advanced pipe-roof high-pressure controlled grouting method provided in an embodiment of the present application.

[0038] Among them, 1. Grouting pipe shed; 11. Grouting port; 12. Grouting hole; 13. Oblique cut; 2. Grouting stop device; 21. First grouting stop section; 22. Second grouting stop section; 3. Grouting stop grouting pipe; 4. Pipe shed guide wall; 5. Guide steel pipe; 6. Surrounding rock; 7. Surrounding rock drilling hole. DETAILED DESCRIPTION

[0039] In order to more clearly understand the above-mentioned objectives, features and advantages of the present application, the scheme of the present application will be further described below. It should be noted that, in the absence of conflict, the embodiments of the present application and the features therein can be combined with each other.

[0040] In the following description, many specific details are set forth to facilitate a full understanding of the present application, but the present application can also be implemented in other ways different from those described herein; it is obvious that the embodiments in the specification are only part of the embodiments of the present application, not all of the embodiments.

[0041] like Figure 1 FIG. 1 is a schematic diagram of the structure of the advanced pipe roof high-pressure controlled grouting device provided in an embodiment of the present application; Figure 2 , which is a schematic diagram of high-pressure controlled grouting performed by the advanced pipe-roof high-pressure controlled grouting device provided in an embodiment of the present application.

[0042] Some embodiments of the present application provide an advanced pipe-roof high-pressure controlled grouting device, comprising: a grouting pipe-roof 1 , a grouting stop device 2 and a grouting stop grouting pipe 3 .

[0043] Among them, a grouting port 11 is formed at one end of the grouting pipe rack 1 along the length direction, and the grouting pipe rack 1 includes a first pipe section relatively close to the grouting port 11 and a second pipe section relatively far away from the grouting port 11, and a plurality of slurry holes 12 are arranged at intervals on the pipe wall of the second pipe section; the grouting device 2 is a film bag woven with fiber cloth, and the grouting device 2 is wrapped around the outer periphery of at least part of the first pipe section of the grouting pipe rack 1, and the length of the grouting device 2 along the length direction of the grouting pipe rack 1 is greater than the thickness of the pipe rack guide wall 4, so that the grouting device 2 can partially extend into the surrounding rock borehole 7 through the pipe rack guide wall 4; the grouting grouting pipe 3 is connected to the grouting device 2, and is used to inject slurry into the grouting device 2, so that the injected slurry squeezes the rock wall of the surrounding rock borehole 7 to play a grouting role.

[0044] Reference Figure 2As shown, a surrounding rock borehole 7 is drilled on the surrounding rock 6, and a grouting pipe rack 1 equipped with a grouting stop device 2 extends into the surrounding rock borehole 7 through the pipe rack guide wall 4.

[0045] The advanced pipe-roof high-pressure controlled grouting device provided in the embodiment of the present application is provided by wrapping a special grouting-stopping device 2 on the grouting pipe-roof 1. The grouting-stopping device 2 is specifically a membrane bag woven with fiber cloth, and the length of the grouting-stopping device 2 along the length direction of the grouting pipe-roof 1 is greater than the thickness of the pipe-roof guide wall 4, and a grouting-stopping grouting pipe 3 is connected to the grouting-stopping device 2. With such an arrangement, when the pipe-roof is installed, the grouting pipe-roof 1 wrapped with the grouting-stopping device 2 can be extended into the surrounding rock borehole 7 through the pipe-roof guide wall 4, and the grouting-stopping device 2 can be partially extended into the surrounding rock borehole 7 through the pipe-roof guide wall 4, and then slurry is injected into the grouting-stopping device 2 through the grouting-stopping grouting pipe 3, and the injected slurry is used to squeeze the rock wall of the surrounding rock borehole 7 to lift it up. The grouting device 2 has a grouting-stopping effect, so that when the grouting pipe roof 1 is subsequently grouted, the grouting pressure can be increased to achieve high-pressure grouting, so that the grouting pipe roof 1 can be fully coupled with the rock wall of the surrounding rock borehole 7, thereby improving the bonding strength between the grouting pipe roof 1 and the surrounding rock 6, and realizing the consolidation of the surrounding rock 6 between the pipe roofs, thereby achieving the purpose of pre-reinforcement of the surrounding rock 6 and reducing the impact of the overall destruction of the surrounding rock caused by the drilling process; and the construction of wrapping the grouting device on the grouting pipe roof 1 and grouting the grouting device is simple, the construction speed is fast, which is conducive to improving the construction quality and has high construction safety.

[0046] It should be noted that the grouting pressure of the existing advance pipe-roof grouting device is generally around 1 MPa, or lower than 1 MPa. The advance pipe-roof high-pressure controlled grouting device provided in the embodiment of the present application can increase the grouting pressure of the advance pipe-roof grouting device to 2.5 MPa, or higher than 2.5 MPa, by installing a special grouting stop device 2 on the grouting pipe-roof 1. In this way, while avoiding slurry seepage, it can ensure that the slurry and the surrounding rock achieve a good compaction and penetration effect, thereby providing good support for the rock formation.

[0047] In some embodiments, reference Figure 2 As shown, the difference between the length of the grouting device 2 along the length direction of the grouting pipe 1 and the thickness of the pipe guide wall 4 is greater than or equal to 1.5 meters. With this arrangement, when the grouting pipe 1 is extended into the surrounding rock borehole 7 through the pipe guide wall 4, it can be ensured that the length of the grouting device 2 extending into the surrounding rock borehole 7 through the pipe guide wall 4 is greater than or equal to 1.5 meters. Figure 2L in the figure represents the length of the grouting stop device 2 extending along the length of the grouting pipe support 1 through the pipe support guide wall 4 into the surrounding rock borehole 7, with L ≥ 1.5 m. This effectively prevents grouting from backflowing and overflowing from the gap formed between the grouting pipe support 1 and the surrounding rock borehole 7 during grouting, as well as grouting from the surface due to shallow burial, thereby providing support for high-pressure grouting in the advanced pipe support.

[0048] In some embodiments, reference Figure 1 and Figure 2 As shown, along the length of the grouting pipe rack 1, the distance between the multiple grouting holes 12 and the grouting port 11 is greater than or equal to 2.5 meters. This arrangement ensures that when the grouting pipe rack 1 extends into the surrounding rock borehole 7 through the pipe rack guide wall 4, the distance between the multiple grouting holes 12 and the orifice of the surrounding rock borehole 7 is greater than 2 meters, thereby effectively preventing slurry overflow.

[0049] In some embodiments, reference Figure 1 and Figure 2 As shown, the grouting device 2 has a receiving cavity arranged around the grouting pipe shed 1, and the grouting device 2 is sealed at both ends along the length direction. The grouting grouting pipe 3 is connected to the end of the grouting device 2 relatively close to the grouting port 11 and communicates with the receiving cavity to inject slurry into the receiving cavity. In this way, when slurry is injected into the receiving cavity of the grouting device 2 through the grouting grouting pipe 3, the injected slurry will inflate the grouting device, so that the grouting device filled with slurry squeezes the rock wall of the surrounding rock borehole 7, thereby forming a good compaction effect between the grouting device 2 and the rock wall of the surrounding rock borehole 7, thereby achieving a good grouting effect, and preventing the injected slurry from seeping out from the grouting device 2 when the grouting pipe shed 1 is subsequently grouted.

[0050] In a specific implementation, the grouting device 2 can be connected to the grouting stop grouting pipe 3 using a special material (such as a composite material). Specifically, the grouting stop 2 can be provided with an installation port that communicates with the accommodating cavity of the grouting stop 2. One end of the grouting stop grouting pipe 3 can be inserted into the installation port and connected to the grouting stop 2 through the composite material, thereby allowing the grouting stop grouting pipe 3 to communicate with the accommodating cavity formed in the grouting stop 2.

[0051] Of course, the specific connection structure between the grouting stop grouting pipe 3 and the grouting stop device 2 is not limited to the above-mentioned limitation, and other methods can also be used to connect the grouting stop grouting pipe 3 to the grouting stop device 2. For example, the grouting stop grouting pipe 3 can be connected to the grouting stop device 2 through a grouting stop connector. Specifically, the grouting stop device 2 is provided with a mounting port, and the grouting stop connector can be a ring-shaped connector fixed at the mounting port. The grouting stop connector can be provided with an external thread, and the end of the grouting stop grouting pipe 3 used for connection with the grouting stop device 2 can be provided with an internal thread. The grouting stop grouting pipe 3 can be screwed and fixed on the grouting stop connector by the cooperation of the internal thread and the external thread, and the grouting stop grouting pipe 3 is connected to the accommodating cavity formed in the grouting stop device 2.

[0052] In some embodiments, reference Figure 1 and Figure 2 As shown, the grouting device 2 includes a first grouting section 21 and a second grouting section 22 which are interconnected along the length direction, and the grouting grouting pipe 3 is connected to the first grouting section 21; a guide steel pipe 5 for the grouting pipe rack 1 to pass through is provided on the pipe rack guide wall 4, and the second grouting section 22 extends into the surrounding rock borehole 7 through the guide steel pipe 5, and the first grouting section 21 is located at the guide steel pipe 5. The first grouting section 21 is used to squeeze the guide steel pipe 5 when the slurry is injected to play a grouting role, and the second grouting section 22 is used to squeeze the rock wall of the surrounding rock borehole 7 when the slurry is injected to play a grouting role.

[0053] It should be understood that after the excavation of the cave entrance protection is completed, the pipe-roof guide wall 4 is constructed first. Usually, a guide steel pipe 5 is installed on the pipe-roof guide wall 4, and then a drilling device is used to drill a hole through the guide steel pipe 5, and then the grouting pipe-roof 1 is inserted into the drilled hole.

[0054] It should be noted that the guide steel pipe 5 is usually an annular steel pipe. Figure 1 The structure shown shows a partial structure of the guide steel pipe 5 , with the purpose of more clearly showing the grouting device located in the guide steel pipe 5 .

[0055] In the above embodiment, after the slurry is injected into the grouting device 2 through the grouting grouting pipe 3, the first grouting section 21 of the grouting device 2 will squeeze the guide steel pipe 5, thereby tightly combining with the inner pipe wall of the guide steel pipe 5, and play a good grouting role. The second grouting section 22 of the grouting device 2 will squeeze the rock wall of the surrounding rock borehole 7, thereby tightly combining with the rock wall of the surrounding rock borehole 7, and play a good grouting role. This arrangement can utilize the grouting device 2 to play a good grouting role.

[0056] In some embodiments, reference Figure 1 and Figure 2As shown, a plurality of slurry holes 12 are arranged at intervals on the pipe wall of the second pipe section of the grouting pipe rack 1, and the plurality of slurry holes 12 are arranged in a plum blossom shape on the pipe wall of the grouting pipe rack 1 to ensure the uniformity of grouting; and the orientation of the slurry holes 12 can be adjusted by rotating the grouting pipe rack 1, so that the orientations of the plurality of slurry holes 12 are staggered from the top area of ​​the grouting pipe rack 1. With such an arrangement, when constructing a shallow buried tunnel entrance, by adjusting the orientation of the grouting pipe rack 1, the orientations of the plurality of slurry holes 12 of the grouting pipe rack 1 are staggered from the top area of ​​the grouting pipe rack 1, so as to effectively prevent the slurry from overflowing from the surface when grouting the grouting pipe rack 1.

[0057] In some embodiments, reference Figure 1 As shown, the grouting pipe rack 1 has an obliquely cut, open end at one end of the grouting pipe rack 1 that is relatively far from the grouting port 11 along its length. That is, an oblique cut 13 is formed at the end of the grouting pipe rack 1 that is relatively far from the grouting port 11 along its length. This arrangement provides a guide for the grouting pipe rack 1 at the end of the grouting pipe rack 1 that is relatively far from the grouting port 11, facilitating smooth placement of the grouting pipe rack 1 into the surrounding rock borehole 7. This is particularly effective when high-pressure grouting is used in soft rock substrates.

[0058] Reference Figure 3 As shown, other embodiments of the present application provide a method for advanced pipe-roof high-pressure controlled grouting, using an advanced pipe-roof high-pressure controlled grouting device as in any of the above embodiments, the method includes the following steps:

[0059] S1, after the excavation of the tunnel entrance protection is completed, the pipe roof guide wall 4 is constructed;

[0060] S2, drilling holes in the surrounding rock around the cave entrance using drilling equipment 7;

[0061] S3, before installing the grouting pipe shed 1, prepare a grouting stop device 2, which is a membrane bag woven from fiber cloth. Wrap the grouting stop device 2 around the outer periphery of the portion of the pipe section of the grouting pipe shed 1 to be installed, and ensure that the length of the grouting stop device 2 along the longitudinal direction of the grouting pipe shed 1 is greater than the thickness of the guide wall 4 of the pipe shed. Connect the grouting stop grouting pipe 3 to the grouting stop device 2;

[0062] S4, extending the grouting pipe 1 equipped with the grouting stop device 2 through the pipe shed guide wall 4 into the surrounding rock drill hole 7, and ensuring that the length of the grouting stop device 2 extending through the pipe shed guide wall 4 into the surrounding rock drill hole 7 is greater than or equal to a preset length value;

[0063] S5, grouting is performed on the grouting device through the grouting stop grouting pipe 3. After the slurry solidifies and reaches a preset strength value, high-pressure controlled grouting is performed on the grouting pipe rack 1.

[0064] The advanced pipe-roof high-pressure controlled grouting method provided in the embodiment of the present application is to prepare a grouting stop device 2 before installing the grouting pipe-roof 1. The grouting stop device 2 is a membrane bag woven of fiber cloth. The grouting stop device 2 is wrapped around the outer periphery of a part of the pipe section of the grouting pipe-roof 1 to be installed, and the length of the grouting stop device 2 along the length direction of the grouting pipe-roof 1 is greater than the thickness of the pipe-roof guide wall 4, and a grouting stop grouting pipe 3 is connected to the grouting stop device 2; then the grouting pipe-roof 1 equipped with the grouting stop device 2 is extended into the surrounding rock borehole 7 through the pipe-roof guide wall 4, and it is ensured that the length of the grouting stop device 2 extended into the surrounding rock borehole 7 through the pipe-roof guide wall 4 is greater than or equal to a preset length value; then slurry is injected into the grouting stop device 2 through the grouting stop grouting pipe 3, so as to use the injected slurry to squeeze the rock wall of the surrounding rock borehole 7 to play a grouting role. After the slurry solidifies and reaches a preset strength value, the grouting pipe shed 1 is grouted. Since the grouting stop device 2 can effectively prevent the leakage of slurry, the grouting pressure can be increased when grouting the grouting pipe shed 1 to achieve high-pressure grouting (the grouting pressure can be greater than or equal to 2.5MPa), so that the grouting pipe shed 1 can be fully coupled with the rock wall of the surrounding rock borehole 7, thereby improving the bonding strength between the grouting pipe shed 1 and the surrounding rock, and achieving the consolidation of the surrounding rock between the pipe sheds, thereby achieving the purpose of pre-reinforcement of the surrounding rock and reducing the impact of the overall destruction of the surrounding rock caused by the drilling process; and the construction of wrapping the grouting device on the grouting pipe shed 1 and grouting the grouting device is simple, the construction speed is fast, which is conducive to improving construction quality, and the construction safety is high. It should be noted that this special grouting stop device 2 can be produced by a factory, which can better improve construction efficiency.

[0065] In some implementations, in S1, the advanced pipe-roof high-pressure controlled grouting method requires the construction of a pipe-roof guide wall 4 after the excavation of the tunnel entrance protection is completed, using either poured concrete or sprayed concrete; in addition, a guide steel pipe 5 can be installed when constructing the guide wall. After the guide wall is laid out, drilling equipment can be used to drill surrounding rocks 7 at the reserved guide steel pipe 5, so that the guide steel pipe 5 can be used to constrain the drilling direction.

[0066] In some embodiments, in S2, when drilling holes 7 in the surrounding rock using drilling equipment, try to use professional large-scale equipment, such as a rotary geological drill, which causes less disturbance and damage to the surrounding rock. When drilling conditions are insufficient, a rotary percussion drill can be used, and try to use professional equipment such as a C6 drill, which has a small hole and a fast speed. If a down-the-hole drill is to be used, each time a first preset length is drilled, a second preset length is overlapped to ensure the drilling direction. For example, each time a hole is drilled for 20 meters, a 5-meter overlap is applied to ensure the drilling direction.

[0067] It should be noted that existing advanced pipe-roof construction methods typically use a down-the-hole drill to drill 30 meters at a time. This will set the upward drift angle based on theoretical parameters. Due to the rigidity and impact of the drilling, the drill rod will sag, leading to bottom hole encroachment and hole expansion, affecting the drilling quality. The advanced pipe-roof high-pressure controlled grouting method provided in the embodiments of the present application, when drilling with a down-the-hole drill, adopts a drilling method with a 5-meter overlap after each 20-meter drilling. This ensures the drilling direction and effectively prevents drill rod sagging, thereby resolving the problems of bottom hole encroachment and hole expansion caused by adjusting the drilling direction during the existing drilling process, and improving the drilling quality.

[0068] In some embodiments, in S3, the grouting pipe rack 1 is installed after the drilling is completed. Before installing the grouting pipe rack 1, a grouting stop device 2 must be made first. The grouting stop device 2 is a membrane bag woven from fiber cloth. The length of the grouting stop device 2 along the length direction of the grouting pipe rack 1 is greater than the thickness of the pipe rack guide wall 4 to ensure that the grouting device has sufficient length. Specifically, the length of the grouting stop device 2 extending into the surrounding rock borehole 7 through the pipe rack guide wall 4 is greater than or equal to a preset length value, for example, greater than or equal to 1.5 meters, so as to effectively inhibit the slurry from flowing back or overflowing from the surface when grouting the grouting pipe rack 1.

[0069] In order to more effectively suppress the slurry from flowing back or overflowing from the surface, in S3, the length of the grouting stop device 2 along the length direction of the grouting pipe pile 1 can be lengthened to increase the length of the grouting stop device 2 extending into the surrounding rock borehole 7 through the pipe pile guide wall 4 along the length direction of the grouting pipe pile 1. For example, the length of the grouting stop device 2 extending into the surrounding rock borehole 7 through the pipe pile guide wall 4 is set to be greater than or equal to 2 meters to suppress the slurry from overflowing from the surface.

[0070] In addition, in order to more effectively suppress the slurry from flowing back or overflowing from the surface, in S4, the directions of the multiple slurry holes 12 on the grouting pipe rack 1 can also be adjusted by rotating the grouting pipe rack 1, so that the directions of the multiple slurry holes 12 are staggered from the top area of ​​the grouting pipe rack 1 to suppress the slurry from overflowing from the surface.

[0071] In some embodiments, in S4, when the grouting pipe rack 1 equipped with the grouting stop device 2 is placed into the surrounding rock borehole 7, large-scale drilling equipment equipped with large-scale pipe rack installation equipment is preferably used to install the pipe rack. If a down-the-hole drilling rig is used, there is generally no matching large-scale pipe rack installation equipment, and most people use an excavator to push the grouting pipe rack 1. However, the excavator's pushing often causes the grouting pipe rack 1 to fail to reach the bottom of the surrounding rock borehole 7, and the top often deviates. Therefore, the grouting pipe rack 1 can be installed by adding two guide chains, which have strong force and facilitate detailed adjustment and control of direction, which is conducive to optimizing the installation of the grouting pipe rack 1. In addition, if a down-the-hole drilling rig is used, the end of the grouting pipe rack 1 away from the grouting port 11 (i.e., the end of the grouting pipe rack 1 extending into the surrounding rock borehole 7) can be configured with an oblique opening. This oblique opening can form a guide structure to guide the grouting pipe rack 1 more smoothly into the surrounding rock borehole 7. This oblique opening is more effective in soft rock matrix.

[0072] In some embodiments, in S5, after the grouting pipe shed 1 is installed, it is necessary to grout the grouting device 2. In order to improve the construction efficiency, a coagulant can be added to the slurry for grouting the grouting device 2 to accelerate the solidification rate of the slurry. After the strength of the solidified slurry reaches the requirement, the grouting pipe shed 1 is subjected to high-pressure controlled grouting. Specifically, the grouting pressure for the high-pressure controlled grouting of the grouting pipe shed 1 can be greater than or equal to 2.5 MPa and less than or equal to 7.5 MPa. For example, the grouting pressure can be 2.5 MPa, 3 MPa, 3.5 MPa, 4 MPa, 6 MPa, 7.5 MPa, etc. Of course, other grouting pressures can also be used as needed.

[0073] In specific implementation, in order to prevent the slurry from flowing back and overflowing from the surface, measures such as lengthening the grouting stop device 2 and / or adjusting the direction of the slurry outlet 12 on the grouting pipe rack 1 can be taken. At the same time, ground observation can be carried out, and the grouting situation can be continuously observed during the high-pressure controlled grouting of the grouting pipe rack 1. If grouting occurs, any one or more of the gel time, grouting pressure, and the water-to-material ratio of the slurry can be adjusted to adjust the diffusion radius of the slurry. In this way, through the advanced pipe rack high-pressure grouting, the coupling of the grouting pipe rack 1 and the surrounding rock 6 and the consolidation of the surrounding rock 6 between the pipe racks are achieved, thereby achieving the purpose of advanced pre-reinforcement of the surrounding rock 6.

[0074] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article, or device comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or elements inherent to such process, method, article, or device. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of other identical elements in the process, method, article, or device comprising the element.

[0075] The foregoing description is intended only to provide specific embodiments of the present application, which will enable those skilled in the art to understand and implement the present application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application is not limited to the embodiments described herein, but is intended to be construed in the broadest manner consistent with the principles and novel features disclosed herein.

Claims

1. An advanced pipe roof high-pressure controlled grouting device, characterized in that: include: A grouting pipe rack, wherein the grouting pipe rack has a grouting port formed at one end thereof along the length direction, the grouting pipe rack comprising a first pipe section relatively close to the grouting port and a second pipe section relatively far from the grouting port, a plurality of slurry outlet holes being arranged at intervals on the pipe wall of the second pipe section, and the grouting pipe rack having a pipe port relatively far from the grouting port along the length direction being obliquely cut and open; A grouting device, the grouting device being a membrane bag woven from fiber cloth, the grouting device being wrapped around the periphery of at least a portion of the first pipe section of the grouting pipe rack, and the length of the grouting device along the length direction of the grouting pipe rack being greater than the thickness of the pipe rack guide wall, so that the grouting device can partially extend into the surrounding rock borehole through the pipe rack guide wall; a grouting stop pipe connected to the grouting stop device and used to inject grout into the grouting stop device so that the injected grout squeezes the rock wall of the surrounding rock borehole to stop grouting; The grouting stop device has a receiving cavity arranged around the grouting pipe shed, and the two ends of the grouting stop device along the length direction are sealed. The grouting stop grouting pipe is connected to one end of the grouting stop device relatively close to the grouting port and communicates with the receiving cavity to inject slurry into the receiving cavity. The grouting device comprises a first grouting section and a second grouting section that are interconnected along the length direction, and the grouting pipe is connected to the first grouting section; A guide steel pipe for the grouting pipe rack to pass through is provided on the guide wall of the pipe rack, the second grouting stop section extends into the surrounding rock drill hole through the guide steel pipe, the first grouting stop section is located at the guide steel pipe, and the first grouting stop section is used to squeeze the guide steel pipe to stop grouting when grout is injected, and the second grouting stop section is used to squeeze the rock wall of the surrounding rock drill hole to stop grouting when grout is injected; The plurality of slurry outlet holes are arranged in a plum blossom shape on the pipe wall of the grouting pipe rack, and the directions of the slurry outlet holes can be adjusted by rotating the grouting pipe rack so that the directions of the plurality of slurry outlet holes are staggered from the top area of ​​the grouting pipe rack.

2. The advanced pipe roof high-pressure controlled grouting device according to claim 1 is characterized in that: The difference between the length of the grouting stop device along the length direction of the grouting pipe shed and the thickness of the pipe shed guide wall is greater than or equal to 1.5 meters; Alternatively, along the length direction of the grouting pipe rack, the distances between the plurality of grouting holes and the grouting port are all greater than or equal to 2.5 meters.

3. A method for high-pressure controlled grouting of an advanced pipe roof, characterized in that: Using the advanced pipe roof high-pressure controlled grouting device according to claim 1 or 2, the method comprises the following steps: S1: After the excavation of the opening protection is completed, the pipe roof guide wall is constructed; S2, drilling holes into the surrounding rock around the cave entrance using drilling equipment; S3, before installing the grouting pipe shed, prepare a grouting stop device, wherein the grouting stop device is a membrane bag woven from fiber cloth, and wrap the grouting stop device around the periphery of a portion of the pipe section of the grouting pipe shed to be installed, wherein the length of the grouting stop device along the longitudinal direction of the grouting pipe shed is greater than the thickness of the guide wall of the grouting pipe shed, and connect the grouting stop grouting pipe to the grouting stop device; S4, extending the grouting pipe rack equipped with the grouting stop device into the surrounding rock drill hole through the pipe rack guide wall, and ensuring that the length of the grouting stop device extending through the pipe rack guide wall into the surrounding rock drill hole is greater than or equal to a preset length value; S5, grouting is performed on the grouting device through the grouting stop grouting pipe, and after the slurry solidifies and reaches a preset strength value, high-pressure controlled grouting is performed on the grouting pipe rack.

4. The advanced pipe roof high-pressure controlled grouting method according to claim 3, characterized in that: In S2, the drilling equipment adopts a rotary geological drill or a rotary percussion drill; or, the drilling equipment adopts a down-the-hole drill, and each time a first preset length is drilled, a second preset length is overlapped to ensure the drilling direction.

5. The advanced pipe roof high-pressure controlled grouting method according to claim 3, characterized in that: In S3, the length of the grouting stop device along the length direction of the grouting pipe roof is lengthened to increase the length of the grouting stop device extending into the surrounding rock borehole through the pipe roof guide wall along the length direction of the grouting pipe roof, so as to suppress slurry from overflowing onto the surface; Alternatively, in S4, the directions of the plurality of slurry outlet holes on the grouting pipe roof are adjusted by rotating the grouting pipe roof so that the directions of the plurality of slurry outlet holes are staggered from the top area of ​​the grouting pipe roof to prevent the slurry from overflowing onto the ground.

6. The advanced pipe roof high-pressure controlled grouting method according to claim 3, characterized in that: In S4, the grouting pipe rack is installed by adding two guide chains; and / or, an oblique opening is provided at one end of the grouting pipe rack away from the grouting port to optimize the installation of the grouting pipe rack.

7. The advanced pipe roof high-pressure controlled grouting method according to claim 3, characterized in that: In S5, the grouting condition is continuously observed during the high-pressure controlled grouting of the grouting pipe-roof. If grouting occurs, any one or a combination of the gel time, the grouting pressure, and the water-to-material ratio of the slurry is adjusted to adjust the diffusion radius of the slurry. Wherein, the grouting pressure of the high-pressure controlled grouting of the grouting pipe rack is greater than or equal to 2.5 MPa and less than or equal to 7.5 MPa.

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