A method and device for pre-grouting the surface of a tunnel to reinforce a shallow buried section

Abstract

The application belongs to the technical field of tunnel engineering construction, and discloses a surface pre-grouting reinforcement method and device for a tunnel broken shallow buried section, and the specific steps of the method comprise the following steps: S1, geological exploration and site preparation: using a geological radar and a drilling sampling method, the surface is explored in detail; according to the exploration result, a broken layer and a region needing reinforcement for grouting are determined; the construction site is cleaned, grouting equipment, sensors and monitoring equipment are arranged, and it is ensured that the equipment normally operates; S2, grouting hole layout before grouting: through the uniform diffusion mechanism, the stretching assembly and the reset assembly are cooperated, the accurate control of the grouting process is realized, the stretching assembly adopts the sliding nested grouting pipe section, the sectional grouting can be carried out according to the requirement, and it is ensured that each grouting region can be uniformly reinforced; the flange ring and the rubber piston in the grouting pipe effectively control the flow of the grouting liquid, and the problem of uneven grouting is avoided.

Description

Technical Field

[0001] This invention belongs to the field of tunnel engineering construction technology, specifically a method and device for surface pre-grouting reinforcement of fractured shallow buried sections of tunnels. Background Technology

[0002] During tunnel construction, especially under complex geological conditions, fractured and shallowly buried sections often become a major challenge. These sections refer to areas where the tunnel is shallowly buried and the soil and rock layers contain significant fractures or weak zones. The soil in these areas has poor stability and is prone to collapse and water seepage, posing serious safety hazards to tunnel construction. To address these issues and ensure smooth tunnel construction, surface pre-grouting reinforcement technology has emerged and is widely used for tunnel reinforcement and stabilization. The principle of surface pre-grouting reinforcement technology is to inject grout into the soil and rock layers of the fractured and shallowly buried sections, filling cracks and voids, thereby improving the overall strength and stability of the soil. This technology effectively enhances soil compaction, improves impermeability, and reduces potential settlement and displacement problems during construction, providing strong support for tunnel construction.

[0003] For example, the invention disclosed in CN112901208B is a comprehensive construction method for shallow-buried sections of urban railway mining tunnels. Addressing the characteristics of shallow tunnel burial, fractured surrounding rock layers, and abundant surface water, the method employs a three-stage temporary invert arch excavation method within the tunnel, greatly ensuring the safety of excavation progress. Furthermore, through in-tunnel pipe roof support and pre-grouting to assist excavation, safe excavation is achieved, improving quality and efficiency, resolving safety hazards in shallow-buried tunnel construction, and reducing the probability of tunnel collapse. In addition, grouting points are arranged in a quincunx pattern at 1-meter intervals within the grouting area defined on the tunnel surface. Grouting pipes with a diameter of 42mm are used for grouting. After grouting, seepage prevention treatment is applied to reduce surface water infiltration and ensure the safety of the construction process.

[0004] The above-mentioned device may cause the following problems when in use: 1. During the grouting process, the grout is prone to backflow through the grouting pipe or borehole, requiring repeated sealing, which affects efficiency; excessive grouting pressure can easily cause surface uplift or pipeline damage, while insufficient pressure leads to inadequate reinforcement effect. Existing devices lack a structure for dynamically adjusting the pressure.

[0005] 2. Since the diffusion of grout depends on the splitting action, it has randomness and dispersion, resulting in reinforcement blind spots or local over-density. It is difficult to achieve segmented control of grouting in open holes. When drilling long holes, the grout cannot diffuse evenly. When the layout of grouting holes is unreasonable, weak areas with uneven reinforcement may be formed, which requires on-site testing to adjust parameters, increasing costs.

[0006] Therefore, a method and device for surface pre-grouting reinforcement of shallow buried sections of tunnels is proposed to solve the problems mentioned in the background art. Summary of the Invention

[0007] To address the problems mentioned in the background section, the present invention provides a method and apparatus for surface pre-grouting reinforcement of fractured shallow buried sections of tunnels.

[0008] To achieve the above objectives, the present invention provides the following technical solution: a method for surface pre-grouting reinforcement of a fractured shallow buried section of a tunnel, the specific steps of which include; S1, Geological Exploration and Site Preparation: Detailed surface surveys were conducted using ground-penetrating radar and borehole sampling. Based on the exploration results, the fractured layer and the areas requiring grouting reinforcement were identified; Clean up the construction site, set up grouting and monitoring equipment, and ensure that the grouting and monitoring equipment are operating normally; S2, Grouting hole layout before grouting: Based on geological exploration data, determine the number, location, depth, and angle of grouting holes; Use a drilling rig to drill grouting holes, ensuring that the hole positions are accurate and consistent with the direction of the fractured layer; Install grouting pipes in the grouting holes and connect them to the grouting pump and pressure monitoring system; S3, Grouting fluid preparation and injection: Prepare appropriate grouting solution according to soil type and reinforcement requirements; Start the grouting equipment and inject grouting fluid hole by hole and layer by layer, controlling the injection pressure, flow rate and time to ensure uniform penetration of the grout; The pressure, flow rate, and soil response during the grouting process are monitored in real time by sensors, and the grouting parameters are dynamically adjusted. S4, Post-grouting monitoring and adjustment: Surface settlement meters and stress sensor equipment are used to monitor surface deformation and soil stability in real time after grouting. The grouting effect is evaluated based on the monitoring data. If uneven reinforcement or missed areas are found, supplementary grouting is carried out and the grouting parameters are adjusted. Quality inspection is conducted in the reinforced area to ensure that the grouting achieves the expected reinforcement effect. S5, Post-construction stability testing and construction summary: After grouting is completed, a period of stability observation is conducted to detect surface settlement, displacement changes, and soil strength. Long-term monitoring of the reinforced area will ensure that the stability of the soil around the tunnel is not affected; Summarize the key issues in the construction process, improve the construction plan, and provide a reference for subsequent projects.

[0009] A surface pre-grouting reinforcement device for a fractured shallow buried section of a tunnel, comprising: The tunnel has an arched ceiling inside. The mounting bracket is fixedly installed inside the tunnel, and the mounting bracket is adapted to the tunnel. Positioning rod; fixedly installed on the top of the mounting frame and fixedly connected to the inner wall of the tunnel; Several auxiliary pipes are installed between the mounting frame and the inner wall of the tunnel; Several grouting pipes are installed inside the auxiliary pipe, and the number of grouting pipes is the same as that of the auxiliary pipes. A backflow prevention mechanism is installed on the outer wall of the auxiliary pipe; A uniform diffusion mechanism is installed inside the grouting pipe; The uniform diffusion mechanism includes a telescopic component and a reset component. The telescopic component is composed of several sliding nested grouting pipes with successively decreasing diameters, used to achieve segmented grouting. Each group of grouting pipes is provided with two flange rings and a rubber piston inside, with the rubber piston located between the two flange rings.

[0010] Preferably, the reset assembly includes a mounting plate fixedly installed on one end of the grouting pipe with the smallest diameter, the diameter of the mounting plate being larger than the outer diameter of the largest grouting pipe.

[0011] Preferably, an installation ring is fixedly fitted on the outer wall of the grouting pipe with the largest diameter, and two connecting ropes are provided on one side of the installation plate. Both connecting ropes pass through the installation ring and are slidably connected to the installation ring.

[0012] Preferably, two flower grooves are opened on the outer wall of the grouting pipe in each group of grouting zones, and each flower groove is designed in a plum blossom shape.

[0013] Preferably, the anti-backflow mechanism includes a plurality of anti-backflow components and a plurality of positioning components, wherein the positioning components are respectively disposed in the middle of two adjacent anti-backflow components.

[0014] Preferably, the anti-backflow assembly includes two fixing rings fixedly fitted on the outer wall of the auxiliary pipe, and protective rings are respectively provided on the side of the two fixing rings that are close to each other.

[0015] Preferably, the ends of the two protective rings that are close to each other are irregularly designed, and in the initial state, the two protective rings are adapted to each other, that is, the outer ends of the two protective rings are completely fitted together.

[0016] Preferably, a plurality of elastic ropes are fixedly installed on one side of the two fixed rings that are close to each other. The plurality of elastic ropes are designed to be equidistantly distributed in a circle with the axis of the auxiliary tube as the center, and the plurality of elastic ropes pass through the two protective rings respectively.

[0017] Preferably, the positioning component includes a positioning frame fixedly installed on the outer wall of two adjacent fixing rings, the positioning frame being triangular in design and having slots on its outer wall.

[0018] Compared with the prior art, the beneficial effects of the present invention are as follows: This invention achieves precise control of the grouting process by setting up a uniform diffusion mechanism through the synergistic action of the telescopic and resetting components. The telescopic component adopts sliding nested grouting pipe sections, which can be grouted in sections as needed to ensure that each grouting area is uniformly reinforced. The flange ring and rubber piston inside the grouting pipe effectively control the flow rate of the grouting fluid, avoiding the problem of uneven grouting. At the same time, the quincunx-shaped groove design not only enhances the structural strength of the grouting pipe, but also improves the flow efficiency of the fluid, further optimizing the grouting effect.

[0019] This invention achieves precise control of grout backflow by setting up an anti-backflow mechanism and cleverly cooperating with a fixed ring and a protective ring. In the initial state, the outer end of the protective ring is completely closed, forming an effective seal. During grouting, the grout pressure causes the protective ring to open automatically, ensuring smooth grout flow. After grouting is completed, the elastic rope returns to its original shape, causing the protective ring to close again, forming a self-recovering seal. This design not only effectively prevents grout backflow but also enhances the adaptability of the component and improves its reliability in complex working environments. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the overall structure of the present invention; Figure 2 This is a partial cross-sectional structural diagram of the tunnel of the present invention; Figure 3 For the present invention Figure 2 A magnified structural diagram of A in the middle; Figure 4 This is a schematic diagram of the combined structure of the anti-backflow mechanism and the uniform diffusion mechanism of the present invention; Figure 5 This is a schematic diagram of the explosion structure of the anti-backflow mechanism and the uniform diffusion mechanism of the present invention; Figure 6 For the present invention Figure 5 A magnified structural diagram of B in the diagram; Figure 7 This is a cross-sectional structural diagram of the anti-backflow mechanism and the uniform diffusion mechanism of the present invention; Figure 8 For the present invention Figure 7 A magnified structural diagram of C; Figure 9 This is a schematic diagram of the exploded structure of the anti-backflow component of the present invention; Figure 10This is a cross-sectional structural diagram of the protective ring of the present invention.

[0021] In the diagram: 1. Tunnel; 11. Mounting frame; 12. Positioning rod; 2. Auxiliary pipe; 21. Fixing ring; 211. Protective ring; 22. Elastic rope; 23. Positioning frame; 24. Circular groove; 3. Grouting pipe; 31. Flower trough; 32. Rubber piston; 33. Flange ring; 34. Mounting plate; 35. Mounting ring; 36. Connecting rope. Detailed Implementation

[0022] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0023] like Figures 1 to 10 As shown, the present invention provides a method for surface pre-grouting reinforcement of fractured shallow buried sections of tunnels, the specific steps of which include: S1, Geological Exploration and Site Preparation: Detailed surface surveys were conducted using ground-penetrating radar and borehole sampling. Based on the exploration results, the fractured layer and the areas requiring grouting reinforcement were identified; Clean up the construction site, set up grouting and monitoring equipment, and ensure that the grouting and monitoring equipment are operating normally; S2, Grouting hole layout before grouting: Based on geological exploration data, determine the number, location, depth, and angle of grouting holes; Use a drilling rig to drill grouting holes, ensuring that the hole positions are accurate and consistent with the direction of the fractured layer; Install grouting pipes in the grouting holes and connect them to the grouting pump and pressure monitoring system; S3, Grouting fluid preparation and injection: Prepare appropriate grouting fluids (such as cement grout, chemical grout, etc.) according to soil type and reinforcement requirements. Start the grouting equipment and inject grouting fluid hole by hole and layer by layer, controlling the injection pressure, flow rate and time to ensure uniform penetration of the grout; The pressure, flow rate, and soil response during the grouting process are monitored in real time by sensors, and the grouting parameters are dynamically adjusted. S4, Post-grouting monitoring and adjustment: Surface settlement meters and stress sensor equipment are used to monitor surface deformation and soil stability in real time after grouting. The grouting effect is evaluated based on the monitoring data. If uneven reinforcement or missed areas are found, supplementary grouting is carried out and the grouting parameters are adjusted. Quality inspection is conducted in the reinforced area to ensure that the grouting achieves the expected reinforcement effect. S5, Post-construction stability testing and construction summary: After grouting is completed, a period of stability observation is conducted to detect surface settlement, displacement changes, and soil strength. Long-term monitoring of the reinforced area will ensure that the stability of the soil around the tunnel is not affected; Summarize the key issues in the construction process, improve the construction plan, and provide a reference for subsequent projects.

[0024] like Figures 1 to 10 As shown, a surface pre-grouting reinforcement device for a fractured shallow buried section of a tunnel includes: a tunnel 1 with an arc-shaped top inside; a mounting frame 11 fixedly installed inside the tunnel 1, the mounting frame 11 being adapted to the tunnel 1; a positioning rod 12 fixedly installed on the top of the mounting frame 11 and fixedly connected to the inner wall of the tunnel 1; several auxiliary pipes 2 disposed between the mounting frame 11 and the inner wall of the tunnel 1; several grouting pipes 3 disposed inside the auxiliary pipes 2, the number being the same as the number of auxiliary pipes 2; an anti-backflow mechanism disposed on the outer wall of the auxiliary pipes 2; and a uniform diffusion mechanism disposed inside the grouting pipes 3. The uniform diffusion mechanism includes a telescopic component and a reset component. The telescopic component consists of several slidingly nested grouting pipes 3 with progressively decreasing diameters, used to achieve segmented grouting. Each grouting pipe 3 in each grouting zone is equipped with two flange rings 33 and a rubber piston 32, with the rubber piston 32 located between the two flange rings 33. The reset component includes a mounting plate 34 fixedly installed on one end of the grouting pipe 3 with the smallest diameter. The diameter of the mounting plate 34 is larger than the outer diameter of the grouting pipe 3 with the largest diameter. A mounting ring 35 is fixedly fitted on the outer wall of the grouting pipe 3 with the largest diameter. Two connecting ropes 36 are provided on one side of the mounting plate 34. Both connecting ropes 36 pass through the mounting ring 35 and are slidably connected to the mounting ring 35. Two flower grooves 31 are opened on the outer wall of the grouting pipe 3 in each grouting zone. Each flower groove 31 is designed in a quincunx shape.

[0025] The above solution is adopted: The mounting frame 11 is fixed inside the tunnel 1, ensuring the entire reinforcement device can work stably and accurately within the tunnel 1. The positioning rod 12, as a key component connecting the mounting frame 11 and the inner wall of the tunnel 1, ensures the precise position of the grouting device within the tunnel 1, avoiding uneven reinforcement due to improper equipment positioning. A uniform diffusion mechanism allows for flexible adjustment according to different grouting requirements. The telescopic component, through the sliding grouting pipe 3 structure, allows for segmented grouting as needed, ensuring uniform and sufficient reinforcement in each grouting area. Each grouting pipe 3 in each grouting area is equipped with a flange ring 33 and a rubber piston 32, which better controls the flow rate of the grouting fluid and avoids… Uneven grouting; the design of the mounting plate 34 and mounting ring 35 in the reset assembly ensures that the reset operation of the grouting device can be carried out smoothly after the grouting process is completed; the design of the mounting plate 34 not only provides physical support, but also allows the device to be adjusted freely during operation through the sliding of the connecting rope 36, ensuring that it can quickly return to the initial state after the grouting process is completed, and avoiding equipment jamming; the flower groove 31 on the outer wall of the grouting pipe 3 in each grouting section is designed in a plum blossom shape, which not only enhances the structural strength of the grouting pipe 3, but also better realizes the uniform diffusion of the grouting liquid; the shape of the flower groove 31 helps the flow and diffusion of the liquid, and at the same time, the plum blossom design also improves the flow efficiency of the fluid, further optimizing the grouting effect.

[0026] like Figures 9 to 10 As shown, the anti-backflow mechanism includes several anti-backflow components and several positioning components. The positioning components are respectively set in the middle of two adjacent anti-backflow components. The anti-backflow component includes two fixing rings 21 fixedly fitted on the outer wall of the auxiliary pipe 2. The two fixing rings 21 are respectively provided with protective rings 211 on the side of the two fixing rings 21 that are close to each other. The ends of the two protective rings 211 that are close to each other are irregularly designed. In the initial state, the two protective rings 211 are adapted to each other, that is, the outer ends of the two protective rings 211 are completely fitted. Several elastic ropes 22 are fixedly installed on the side of the two fixing rings 21 that are close to each other. The several elastic ropes 22 are all designed to be equidistantly distributed in circles with the axis of the auxiliary pipe 2 as the center. The several elastic ropes 22 pass through the two protective rings 211 respectively. The positioning component includes a positioning frame 23 fixedly installed on the outer wall of two adjacent fixing rings 21. The positioning frame 23 is triangular in design and has slots on its outer wall.

[0027] The above-mentioned solution: The anti-backflow component, fixedly mounted on two fixing rings 21 on the outer wall of the auxiliary pipe 2, effectively prevents grout from flowing back during the grouting process. The irregular design of the protective rings 211 on both sides of the fixing rings 21 ensures that the outer ends of the protective rings 211 are completely fitted in the initial state, maximizing the anti-backflow effect when there is no external force. The irregular design of the protective rings 211 provides appropriate elastic deformation when needed, better adapting to different working environments and pressure changes, preventing unnecessary backflow or leakage. The elastic ropes 22 on the fixing rings 21 are installed in a circumferentially distributed manner, ensuring that the elastic tension of the anti-backflow component is always within an appropriate range. When external force acts on the anti-backflow component, the elastic ropes 22 provide flexible support and protection, preventing the component's deformation from exceeding the set range. This elastic design not only enhances the adaptability of the anti-backflow component but also improves its reliability in high-pressure working environments. Working principle and usage process of this invention: During the construction preparation phase, the construction personnel will place the auxiliary pipe 2 between the tunnel 1 and the mounting frame 11 to ensure its precise position. The positioning rod 12 is inserted into the slot of the positioning frame 23. With the support of the positioning rod 12, the auxiliary pipe 2 is firmly fixed between the tunnel 1 and the mounting frame 11. This fixing process ensures the stability of the auxiliary pipe 2 in the tunnel 1 during grouting operations, and will not be displaced due to external forces or vibrations, thereby ensuring the smooth progress of subsequent work. After the auxiliary pipe 2 is installed, the grouting pipe 3 is inserted into each auxiliary pipe 2 in sequence. A pressure sensor is installed at the tail end of the grouting pipe 3. The pressure sensor is connected to the controller of the linear drive mechanism and has the function of monitoring and feeding back the grouting pressure. When the grouting system is started and grouting begins, the pressure sensor will detect the pressure in the grouting pipe 3 in real time and feed back a signal to the controller when the pressure reaches the set value. After receiving the signal, the controller will instruct the linear drive mechanism to start, so that the telescopic grouting pipe 3 retracts to the set distance to achieve precise grouting control. The grouting system, connected to the grouting pump, begins by sending grout through the grouting pipe 3 into the auxiliary pipe 2. After entering the grouting pipe 3, the grout flows through the groove 31 inside the grouting pipe 3 and further into the gap of the auxiliary pipe 2. At this point, the circular groove 24 inside the auxiliary pipe 2 becomes the outlet for grout release. When the grout passes through the circular groove 24, the elastic rope 22 deforms due to the internal pressure, causing the protective ring 211 at the end to automatically open outward under pressure. As the protective ring 211 opens, the grout can flow smoothly out of the circular groove 24 and be injected into the formation. The protective ring 211 has the ability to self-recover; after the grouting process is completed, the elastic rope 22 will return to its original shape due to the disappearance of external pressure, so that the two protective rings 211 will re-fit and form a sealed state, preventing the grout from flowing back into the grouting pipe 3, and effectively avoiding the potential damage of the grout backflow to the grouting pipe 3. Ensuring the smooth operation and stability of the grouting system is crucial, especially in the event of equipment failure. The connecting rope 36 allows construction personnel to effectively address situations where the grouting pipe 3 cannot be retrieved normally due to sensor malfunction or other reasons. The connecting rope 36 serves as an emergency mechanism and acts as a backup. When the sensor or grouting pipe 3 malfunctions and cannot be retrieved by the automatic control system, construction personnel can manually pull the connecting rope 36. One end of the connecting rope 36 is connected to the mounting plate 34, which is part of the entire grouting system and located at the position of the grouting pipe 3. By pulling the connecting rope 36, construction personnel can move the mounting plate 34 and the topmost grouting pipe 3 towards the retrieval position.

[0028] 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, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0029] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A surface pre-grouting reinforcement device for fractured shallow buried sections of tunnels, characterized in that, include; The tunnel (1) has an arc-shaped ceiling inside; Mounting bracket (11) is fixedly installed inside the tunnel (1), and the mounting bracket (11) is adapted to the tunnel (1); Positioning rod (12); fixedly installed on the top of the mounting frame (11) and fixedly connected to the inner wall of the tunnel (1); Several auxiliary pipes (2) are arranged between the mounting frame (11) and the inner wall of the tunnel (1); Several grouting pipes (3) are installed inside the auxiliary pipe (2) and the number of them is the same as that of the auxiliary pipe (2); A backflow prevention mechanism is provided on the outer wall of the auxiliary pipe (2); A uniform diffusion mechanism is provided inside the grouting pipe (3); The uniform diffusion mechanism includes a telescopic component and a reset component. The telescopic component is composed of several sliding nested grouting pipes (3) with decreasing diameters in sequence, which are used to realize segmented grouting. Each grouting pipe (3) in the grouting zone is provided with two flange rings (33) and a rubber piston (32). The rubber piston (32) is located in the middle of the two flange rings (33). The reset assembly includes a mounting plate (34) fixedly installed on one end of the grouting pipe (3) with the smallest diameter value, the diameter value of the mounting plate (34) being greater than the outer diameter value of the largest grouting pipe (3); An installation ring (35) is fixedly sleeved on the outer wall of the grouting pipe (3) with the maximum diameter. Two connecting ropes (36) are provided on one side of the installation plate (34). Both connecting ropes (36) pass through the installation ring (35) and are slidably connected to the installation ring (35). The anti-backflow mechanism includes several anti-backflow components and several positioning components, wherein the positioning components are respectively disposed between two adjacent anti-backflow components; The anti-backflow assembly includes two fixing rings (21) fixedly mounted on the outer wall of the auxiliary pipe (2), and protective rings (211) are respectively provided on the side of the two fixing rings (21) that are close to each other.

2. The surface pre-grouting reinforcement device for fractured shallow buried sections of tunnels according to claim 1, characterized in that: Two flower grooves (31) are opened on the outer wall of the grouting pipe (3) in each grouting zone, and each flower groove (31) is designed in a plum blossom shape.

3. The surface pre-grouting reinforcement device for fractured shallow buried sections of tunnels according to claim 1, characterized in that: The two protective rings (211) have irregular designs at their close ends. In the initial state, the two protective rings (211) are matched, that is, the outer ends of the two protective rings (211) are completely fitted together.

4. The surface pre-grouting reinforcement device for fractured shallow buried sections of tunnels according to claim 1, characterized in that: Several elastic ropes (22) are fixedly installed on the side of the two fixed rings (21) that are close to each other. The elastic ropes (22) are all designed to be equidistantly distributed in a circle with the axis of the auxiliary tube (2) as the center. The elastic ropes (22) pass through the two protective rings (211) respectively.

5. The surface pre-grouting reinforcement device for fractured shallow buried sections of tunnels according to claim 1, characterized in that: The positioning component includes a positioning frame (23) fixedly installed on the outer wall of two adjacent fixing rings (21). The positioning frame (23) is triangular in design and has slots on its outer wall.

6. A method for surface pre-grouting reinforcement of a fractured shallow-buried section of a tunnel, applied to the surface pre-grouting reinforcement device for a fractured shallow-buried section of a tunnel as described in any one of claims 1-5, characterized in that... The specific steps of this method include: S1, Geological Exploration and Site Preparation: Detailed surface surveys were conducted using ground-penetrating radar and borehole sampling. Based on the exploration results, the fractured layer and the areas requiring grouting reinforcement were identified; Clean up the construction site, set up grouting and monitoring equipment, and ensure that the grouting and monitoring equipment are operating normally; S2, Grouting hole layout before grouting: Based on geological exploration data, determine the number, location, depth, and angle of grouting holes; Use a drilling rig to drill grouting holes, ensuring that the hole positions are accurate and consistent with the direction of the fractured layer; Install grouting pipes in the grouting holes and connect them to the grouting pump and pressure monitoring system; S3, Grouting fluid preparation and injection: Prepare appropriate grouting solution according to soil type and reinforcement requirements; Start the grouting equipment and inject grouting fluid hole by hole and layer by layer, controlling the injection pressure, flow rate and time to ensure uniform penetration of the grout; The pressure, flow rate, and soil response during the grouting process are monitored in real time by sensors, and the grouting parameters are dynamically adjusted. S4, Post-grouting monitoring and adjustment: Surface settlement meters and stress sensor equipment are used to monitor surface deformation and soil stability in real time after grouting. The grouting effect is evaluated based on the monitoring data. If uneven reinforcement or missed areas are found, supplementary grouting is carried out and the grouting parameters are adjusted. Quality inspection is conducted in the reinforced area to ensure that the grouting achieves the expected reinforcement effect. S5, Post-construction stability testing and construction summary: After grouting is completed, a period of stability observation is conducted to detect surface settlement, displacement changes, and soil strength. Long-term monitoring of the reinforced area will ensure that the stability of the soil around the tunnel is not affected; Summarize the key issues in the construction process, improve the construction plan, and provide a reference for subsequent projects.

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