Advanced reinforcement method for water-rich tunnel
By first injecting thixotropic grout into water-rich strata to form a gel, and then spraying cement-based grout to form a reinforced body, the problems of uneven grout diffusion and insufficient strength in traditional methods are solved, achieving efficient tunnel reinforcement and construction safety.
Patent Information
- Application Number
- CN202511858904.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-10
- Publication Date
- 2026-02-06
AI Technical Summary
When excavating tunnels in water-rich strata, traditional advanced grouting reinforcement methods are prone to uneven grout diffusion, slow strength growth, and easy dilution and erosion by groundwater in high-pressure water-rich environments, making it difficult to guarantee the reinforcement effect and posing safety hazards during tunnel construction.
A combination of thixotropic grout and cement-based grout is used. First, thixotropic grout is injected through the grouting hole to form a gel. Then, cement-based grout is sprayed using a high-pressure nozzle to form a solidified body. The thixotropic grout provides the forming conditions for the gel, and the cement-based grout penetrates under high pressure and mixes with the gel to solidify, forming a high-strength solidified body.
It significantly improves the grouting effect and reinforcement reliability, reduces construction risks such as water inrush and collapse, and ensures tunnel construction safety.
Smart Images
Figure CN121473840A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the technical field of tunnel construction, in particular to a water-rich tunnel advanced reinforcement method. BACKGROUND
[0002] When excavating a tunnel in a water-rich stratum, the self-stability of surrounding rock is poor due to high groundwater pressure and strong permeability, and accidents such as water gushing, mud bursting and collapse are prone to occur. The traditional advanced grouting reinforcement usually uses a single cement-based slurry, which is prone to uneven slurry diffusion, slow strength growth, and easy dilution and erosion by groundwater in a high-pressure water-rich environment. The reinforcement effect is difficult to guarantee, and it is easy to cause engineering risks such as water gushing and collapse during tunnel construction, which poses a safety hazard. SUMMARY
[0003] The main purpose of the present application is to provide a water-rich tunnel advanced reinforcement method, which aims to solve the technical problems of poor reinforcement effect of advanced grouting in water-rich stratum tunnel in the prior art and safety hazards.
[0004] To achieve the above-mentioned purpose, the water-rich tunnel advanced reinforcement method provided by the present application comprises the following steps: preparing a thixotropic slurry and a cement-based slurry; drilling a grouting hole in the stratum around the tunnel; injecting the thixotropic slurry into the grouting hole through a grouting pipe; forming a gel after the thixotropic slurry mixes with the geological body around the grouting hole; lowering a spray pipe with a high-pressure spray head into the grouting hole; spraying the cement-based slurry into the gel through the high-pressure spray head; and forming a reinforced body after the cement-based slurry mixes with the gel around the grouting hole and solidifies.
[0005] In an embodiment, the step of preparing a thixotropic slurry and a cement-based slurry comprises: adding water, sodium-based bentonite, cement and a thixotropic agent into a first container in sequence and continuously stirring until uniformly mixed to form the thixotropic slurry; and adding water, cement and a water-reducing agent into a second container in sequence and continuously stirring until uniformly mixed to form the cement-based slurry.
[0006] In an embodiment, the step of adding water, sodium-based bentonite, cement and a thixotropic agent into a first container in sequence and continuously stirring until uniformly mixed to form the thixotropic slurry comprises: adding water and sodium-based bentonite into the first container and stirring at high speed to form a base slurry; adding cement into the base slurry and stirring at medium speed to form a semi-finished product slurry; and adding a thixotropic agent into the semi-finished product slurry and stirring at low speed to form the thixotropic slurry.
[0007] In an embodiment, the thixotropic agent is a modified nanocellulose crystal or a polyamide wax.
[0008] In an embodiment, the weight ratio of each component in the thixotropic slurry is: water 160-240 parts, sodium bentonite 40-80 parts, cement 200 parts, and thixotropic agent 1-6 parts.
[0009] In an embodiment, the weight ratio of each component in the cement-based slurry is: water 100-140 parts, cement 200 parts, and water reducing agent 1-3 parts.
[0010] In an embodiment, the step of injecting the thixotropic slurry into the grouting hole through the grouting pipe comprises: lowering the grouting pipe to the bottom of the grouting hole; connecting a grouting pump to the grouting pipe to inject the thixotropic slurry into the grouting hole at an initial grouting pressure; monitoring the grouting pressure by the grouting pump, and stopping grouting when the grouting pressure stably rises to a target pressure and maintains for a preset time; and slowly taking out the grouting pipe.
[0011] In an embodiment, the step of injecting the cement-based slurry into the gel through the high-pressure nozzle comprises: delivering the cement-based slurry and high-pressure airflow to the high-pressure nozzle through a high-pressure pump set and an air compressor, respectively; spraying the cement-based slurry and the high-pressure airflow at high speed through the high-pressure nozzle, while cutting and stirring the gel and the surrounding soil; rotating the nozzle while lifting the nozzle, continuously spraying the cement-based slurry from the bottom to the top of the grouting hole.
[0012] In an embodiment, the number of grouting holes is multiple, and the multiple grouting holes are distributed in a quincunx shape.
[0013] In an embodiment, after the step of forming a gel by mixing the thixotropic slurry and the surrounding geological body around the grouting hole, the method further comprises: drilling an inspection hole in the stratum outside the tunnel; the inspection hole is arranged at intervals with the grouting hole; measuring the water yield in the inspection hole and checking the water quality in the inspection hole; judging the impermeability of the gel according to the water yield and the water quality.
[0014] The water-rich tunnel advance reinforcement method provided by the present application drills grouting holes, injects thixotropic slurry and cement-based slurry into the grouting holes in sequence, first forms a preliminary gel with the thixotropic slurry to stabilize the geological conditions and block water, and then forms a reinforced body by high-pressure spraying of the cement-based slurry. The gel formed by the thixotropic slurry and the surrounding geological body provides good forming conditions for the solidification of the cement-based slurry, ensuring the forming quality of the reinforced body. The method not only improves the grouting effect and reinforcement reliability, but also significantly reduces the construction risks such as water gushing and collapse during tunnel excavation in water-rich strata, ensuring the safety of subsequent tunnel construction. BRIEF DESCRIPTION OF DRAWINGS
[0015] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.
[0016] Figure 1 This is a flowchart illustrating an embodiment of the advanced reinforcement method for water-rich tunnels provided by the present invention. Figure 2 for Figure 1 A detailed flowchart of step S10; Figure 3 for Figure 1 A detailed flowchart of step S30; Figure 4 for Figure 1 A detailed flowchart of step S60.
[0017] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation
[0018] 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 a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.
[0019] It should be noted that if the embodiments of the present invention involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a specific posture. If the specific posture changes, the directional indicators will also change accordingly.
[0020] Furthermore, if the embodiments of this invention involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the use of "and / or" or "and / or" throughout the text includes three parallel solutions. For example, "A and / or B" includes solution A, solution B, or a solution where both A and B are satisfied simultaneously. Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this invention.
[0021] Excavating tunnels in water-rich strata often presents challenges due to the high pressure and permeability of groundwater, which leads to poor self-stability of the surrounding rock and a high risk of accidents such as water inrush, mudslides, and collapses. Traditional pre-grouting reinforcement typically uses a single cement-based grout, which is prone to uneven grout diffusion, slow strength development, and susceptibility to dilution and erosion by groundwater in high-pressure, water-rich environments. This makes it difficult to guarantee the reinforcement effect and increases the risk of water inrush and collapses during tunnel construction, posing safety hazards.
[0022] This invention proposes a method for advanced reinforcement of water-rich tunnels, comprising the following steps: S10: Preparation of thixotropic slurry and cement-based slurry; S20: Drill grouting holes in the strata surrounding the tunnel; S30: Inject the thixotropic slurry into the grouting hole through the grouting pipe; S40: After the thixotropic slurry and the geological body surrounding the grouting hole are mixed, a gel is formed; S50: Lower the nozzle with the high-pressure nozzle into the grouting hole; S60: The cement-based slurry is sprayed into the gel body through the high-pressure nozzle; S70: After the cement-based grout and the gel around the grouting hole are mixed and solidified, a solidified body is formed.
[0023] Please see Figure 1 , Figure 1This is a flowchart illustrating an embodiment of the pre-reinforcement method for water-rich tunnels provided by the present invention. The pre-reinforcement method for water-rich tunnels proposed in this invention is applicable to the reinforcement and waterproofing of surrounding rock before tunnel excavation under water-rich geological conditions. Before the construction of the water-rich tunnel, thixotropic grout and cement-based grout are prepared separately. The thixotropic grout exhibits thixotropy, meaning it has good fluidity during mixing or grouting and can be smoothly injected into the pores of the strata; while in a static state, it rapidly forms a gel-like structure, possessing certain strength and impermeability. The cement-based grout uses cement as the main cementing material and can be mixed with admixtures as needed to improve its fluidity, setting time, or final strength. Grouting holes are drilled in the strata surrounding the tunnel excavation outline. The thixotropic grout is injected into the grouting holes through grouting pipes. Under pressure, the grout penetrates into the pores of the surrounding soil or rock mass and undergoes physicochemical reactions with water and particles in the geological body. After the thixotropic grout settles, it mixes with the surrounding geological body and gradually forms a gel with certain strength and impermeability. The gel not only fills the existing pores but also blocks the seepage path of external groundwater to a certain extent. Subsequently, a nozzle equipped with a high-pressure nozzle is lowered into the same grouting hole. Cement-based grout is then injected at high pressure into the formed gel. Under high pressure, the cement-based grout further penetrates, splits, and displaces some of the water in the gel, mixing with it. After the cement-based grout solidifies, it and the surrounding gel together form a solidified body with strong integrity, high density, and a certain structural strength. This solidified body effectively seals seepage channels in water-rich strata, enhances the self-stabilizing ability and impermeability of the surrounding rock, and provides safe and reliable working conditions for subsequent tunnel excavation.
[0024] The proposed method for advanced reinforcement of water-rich tunnels involves drilling grouting holes and injecting thixotropic grout and cement-based grout sequentially into them. First, the thixotropic grout forms a preliminary gel to stabilize geological conditions and block water. Then, the cement-based grout is injected under high pressure to form a reinforced body. The gel formed by the thixotropic grout and the surrounding geological body provides excellent forming conditions for the cement-based grout to solidify, ensuring the quality of the reinforced body. This method not only improves the grouting effect and reinforcement reliability but also significantly reduces the construction risks of water inrush and collapse during tunnel excavation in water-rich strata, ensuring the safety of subsequent tunnel construction.
[0025] In one embodiment, step S10 includes: S11: Water, sodium bentonite, cement and thixotropic agent are added sequentially to the first container and stirred continuously until uniformly mixed to form the thixotropic slurry; S12: Add water, cement and water-reducing agent to the second container in sequence, and continue stirring until they are evenly mixed to form the cement-based slurry.
[0026] Please see Figure 2 , Figure 2 forFigure 1 A detailed flowchart of step S10 is shown below. In preparing the thixotropic grout, water, sodium bentonite, cement, and a thixotropic agent are added sequentially to the first container. Water serves as a dispersion medium, providing a basis for uniform mixing of the components. Sodium bentonite rapidly hydrates and expands upon contact with water, forming a high-viscosity gel-like matrix. This not only imparts excellent suspension stability and high water retention to the grout but also effectively seals larger pores in the strata. Cement provides the basic strength of the structure, ensuring that the final solidified body not only possesses good flexibility and impermeability but also a certain degree of long-term stability and durability. The thixotropic agent significantly enhances the thixotropy of the grout, reducing its viscosity and increasing its fluidity during stirring or pumping, facilitating injection. After grouting and settling, the thixotropic grout rapidly transforms into a gel state, thereby constructing a temporary water-stopping barrier within the geological body surrounding the tunnel. This prevents excessive diffusion or loss of the cement-based grout during subsequent grouting processes, improving grouting efficiency and controllability. Cement-based grout consists of water, cement, and water-reducing agents, giving it good fluidity and suitable setting properties. It can penetrate into the gel through a high-pressure jetting process and form a high-strength solidified body after solidification.
[0027] By independently preparing thixotropic grout and cement-based grout in the first and second containers respectively, precise and independent control over the formulation, concentration, and process parameters of different grouts is achieved. This preparation method allows construction personnel to flexibly adjust the composition and properties of each grout according to the actual geological conditions, thereby significantly improving the adaptability, reliability, and final overall reinforcement effect of the reinforcement measures.
[0028] In one embodiment, step S11 includes: S111: Add water and sodium-based bentonite to the first container and stir at high speed to form a base slurry; S112: Add cement to the base slurry and stir at medium speed to form a semi-finished slurry; S113: Add thixotropic agent to the semi-finished slurry and stir at low speed to form the thixotropic slurry.
[0029] It should be noted that adding sodium-based bentonite to water and stirring at high speed rapidly disperses the sodium-based bentonite particles in the water through the strong mechanical shear force of high-speed stirring, allowing them to fully hydrate and expand, forming a uniform colloidal slurry. This prevents the slurry from becoming heterogeneous due to insufficient stirring intensity, which would severely affect its suspension and sealing performance. Adding cement to the slurry and stirring at medium speed provides sufficient stirring intensity to achieve uniform mixing of cement and slurry, while avoiding premature hydration of cement, increased slurry temperature, and excessive air introduction caused by the mechanical shear force generated during stirring, thus preventing accidental loss of slurry fluidity or the formation of bubbles. Finally, adding a thixotropic agent to the semi-finished slurry and stirring at low speed avoids damaging the polymer in the thixotropic agent during stirring, protecting the molecular structure integrity of the thixotropic agent, and thus ensuring the molding quality of the thixotropic slurry.
[0030] In one embodiment, the thixotropic agent is modified nanocellulose crystals or polyamide wax.
[0031] Furthermore, the thixotropic agent utilizes existing technologies such as modified nanocellulose crystals or polyamide wax. Modified nanocellulose crystals possess extremely high specific surface area and abundant surface hydroxyl groups, allowing for better dispersion in water after modification. This results in a very fine and stable thixotropic slurry, and its bio-based material properties make it more environmentally friendly. Polyamide wax, on the other hand, generates thixotropy by forming an extremely fine microcrystalline gel network in oil and water. It exhibits extremely strong shear and thermal stability, providing the thixotropic slurry with very strong and long-lasting anti-settling and anti-sagging effects.
[0032] In one embodiment, the weight ratio of each component in the thixotropic slurry is as follows: 160-240 parts water, 40-80 parts sodium bentonite, 200 parts cement, and 1-6 parts thixotropic agent.
[0033] Understandably, using 200 parts cement as the preparation calculation baseline, a water content of 160 parts results in a thicker thixotropic slurry with higher gel strength, suitable for formations with low permeability or requiring higher early strength. Increasing the water content to 240 parts results in excellent fluidity, easy pumping, and penetration into finer formation pores, suitable for formations with poor permeability or requiring a wider diffusion range. Naphazobentonite at 40 parts provides basic suspension and thickening effects; increasing to 80 parts significantly improves the viscosity and gel strength of the thixotropic slurry, forming a denser and more resilient isolation layer that effectively resists groundwater erosion and pressure. A thixotropic agent at 1 part provides a noticeable thixotropic effect, while 6 parts result in higher static gel strength, effectively resisting high-pressure water inrush and preventing slurry dispersion or excessive loss, suitable for water-rich tunnels with ample flowing water. The specific dosage of each component in the thixotropic slurry is adjusted according to the specific conditions of the water-rich tunnel strata.
[0034] In one embodiment, the weight ratio of each component in the cement-based slurry is: 100-140 parts water, 200 parts cement, and 1-3 parts water-reducing agent.
[0035] Similarly, the lower the water content in the cement-based grout, the lower its fluidity, making it suitable for situations with strong groundwater scouring in water-rich strata. Higher water content results in better fluidity, facilitating the grout's flow into the stratum's pores. Likewise, water-reducing agents can maintain the necessary fluidity of the cement-based grout while increasing its density, thereby contributing to improved final strength and impermeability of the reinforced body. Based on the specific stratum permeability, water content, pore pressure, and engineering requirements for the reinforced body's strength and diffusion range in the water-rich tunnel section, adaptive adjustments are made within this ratio range to precisely optimize the cement-based grout's performance and ensure optimal pre-reinforcement effects. It should be noted that the sodium-based bentonite, cement, thixotropic agent, and water-reducing agent in this invention all utilize existing technologies.
[0036] In one embodiment, step S30 includes: S31: Lower the grouting pipe to the bottom of the grouting hole; S32: Connect a grouting pump to the grouting pipe and inject the thixotropic grout into the grouting hole at an initial grouting pressure; S33: The grouting pressure is monitored by the grouting pump. When the grouting pressure rises steadily to the target pressure and is maintained for a preset time, the grouting is stopped. S34: Slowly remove the grouting pipe.
[0037] Please see Figure 3 , Figure 3 for Figure 1 A detailed flowchart of step S30 is shown below. First, the grouting pipe is smoothly lowered to the bottom of the grouting hole, ensuring the grout outlet reaches the preset depth. Then, the grouting pump is connected, and thixotropic grout is pumped into the grouting hole at the initial grouting pressure, allowing the thixotropic grout to initially penetrate and fill the surrounding strata under low pressure. During the grouting process, pressure changes are monitored in real time via the grouting pump. As the thixotropic grout is continuously injected and the strata pores are gradually filled, the grouting pressure steadily increases. When the pressure reaches the preset target value and is maintained for a specified time, the grouting is considered complete, and grouting is immediately stopped. Finally, after confirming the completion of grouting, the grouting pipe is slowly and evenly removed from the grouting hole to avoid disturbing the formed gel, thereby ensuring that the thixotropic grout is evenly distributed in the strata around the hole and effectively sealing the seepage path.
[0038] In one embodiment, step S60 includes: S61: The cement-based slurry and high-pressure airflow are respectively delivered to the high-pressure nozzle by a high-pressure pump set and an air compressor; S62: The cement-based slurry and the high-pressure airflow are sprayed out at high speed through the high-pressure nozzle, while simultaneously cutting and mixing the gel and the surrounding soil; S63: Rotate the nozzle and simultaneously raise the nozzle to continuously spray the cement-based grout from the bottom to the top of the grouting hole.
[0039] Please see Figure 4 , Figure 4 for Figure 1 A detailed flowchart of step S60 is shown below. First, the pre-prepared cement-based slurry is transported to the high-pressure nozzle via a high-pressure pump set. Simultaneously, a high-pressure airflow generated by an air compressor is also transported to the high-pressure nozzle via the same pipeline system. Then, the high-pressure nozzle is activated, and the cement-based slurry and high-pressure airflow are mixed and sprayed out at high speed. The enormous kinetic energy of the cement-based slurry and high-pressure airflow is used to effectively cut, break, and strongly mix the formed gel and the surrounding soil, ensuring thorough mixing with the cement-based slurry. During this process, the nozzle is rotated at a uniform speed to ensure uniform spray coverage. At the same time, the nozzle is slowly raised from the bottom to the top of the grouting hole at a controlled speed, thereby achieving continuous, complete, and uniform spray reinforcement of the gel and strata along the hole depth direction, ultimately forming a reinforced body with strong integrity, high density, and controllable properties.
[0040] In one embodiment, there are multiple grouting holes, which are distributed in a quincunx pattern.
[0041] Understandably, the grouting holes are distributed in a quincunx pattern, so that the diffusion radius of the thixotropic grout or cement-based grout can overlap with the diffusion areas of multiple adjacent grouting holes, forming a continuous and uniformly strong reinforced area on the plane, thus forming a continuous and effective three-dimensional reinforced body, thereby ensuring the waterproof effect of the reinforced body.
[0042] In one embodiment, after step S40, the method further includes the step of: S41: Drill inspection holes in the strata surrounding the tunnel; the inspection holes are spaced apart from the grouting holes; S42: Measure the water flow rate in the inspection hole and check the water quality in the inspection hole; S43: The impermeability of the gel is determined by the outflow rate and the water quality.
[0043] It can be explained that the impermeability of the gel is tested by observing the outflow and water quality within the inspection well. When the outflow is small and stable, and the water is clear, it indicates that the gel is of good quality, and the solid particles within it have been effectively filtered as the groundwater passes through, proving that the formation pores have been effectively filled by the thixotropic slurry, resulting in a dense gel. Conversely, when the outflow is large or uneven, or the groundwater is turbid, it indicates that the gel is being eroded and carried away, suggesting poor gel quality.
[0044] The above description is merely an exemplary embodiment of the present invention and does not limit the scope of protection of the present invention. Any equivalent structural transformations made based on the technical concept of the present invention and the contents of the specification and drawings of the present invention, or direct / indirect applications in other related technical fields, are included within the scope of protection of the present invention.
Claims
1. A method for advanced reinforcement of water-rich tunnels, characterized in that, Including the following steps: Preparation of thixotropic slurries and cement-based slurries; Grouting holes were drilled in the strata surrounding the tunnel. The thixotropic slurry is injected into the grouting hole through the grouting pipe; After the thixotropic slurry mixes with the geological body surrounding the grouting hole, a gel is formed. The nozzle with the high-pressure nozzle is lowered into the grouting hole; The cement-based slurry is sprayed into the gel body through the high-pressure nozzle; After the cement-based grout and the gel around the grouting hole are mixed and solidified, a solidified body is formed.
2. The method for advanced reinforcement of water-rich tunnels as described in claim 1, characterized in that, The steps for preparing the thixotropic slurry and the cement-based slurry include: Water, sodium bentonite, cement and thixotropic agent are added sequentially to the first container and stirred continuously until uniformly mixed to form the thixotropic slurry; Water, cement, and water-reducing agent are added sequentially to the second container, and the mixture is stirred continuously until it is uniformly mixed to form the cement-based slurry.
3. The method for advanced reinforcement of water-rich tunnels as described in claim 2, characterized in that, The step of sequentially adding water, sodium bentonite, cement, and thixotropic agent to a first container and continuously stirring until uniformly mixed to form the thixotropic slurry includes: Water and sodium-based bentonite were added to the first container and stirred at high speed to form a base slurry; Cement is added to the base slurry and stirred at medium speed to form a semi-finished slurry; A thixotropic agent is added to the semi-finished slurry and stirred at low speed to form the thixotropic slurry.
4. The method for advanced reinforcement of water-rich tunnels as described in claim 2, characterized in that, The thixotropic agent is a modified nanocellulose crystal or a polyamide wax.
5. The method for advanced reinforcement of water-rich tunnels as described in claim 2, characterized in that, The weight ratio of each component in the thixotropic slurry is as follows: 160-240 parts water, 40-80 parts sodium bentonite, 200 parts cement, and 1-6 parts thixotropic agent.
6. The method for advanced reinforcement of water-rich tunnels as described in claim 2, characterized in that, The weight ratio of each component in the cement-based slurry is as follows: 100-140 parts water, 200 parts cement, 1-3 parts water-reducing agent.
7. The method for advanced reinforcement of water-rich tunnels as described in any one of claims 1 to 6, characterized in that, The step of injecting the thixotropic slurry into the grouting hole through the grouting pipe includes: Lower the grouting pipe to the bottom of the grouting hole; A grouting pump is connected to the grouting pipe, and the thixotropic grout is injected into the grouting hole at an initial grouting pressure. The grouting pressure is monitored by the grouting pump. Grouting is stopped when the grouting pressure rises steadily to the target pressure and is maintained for a preset time. Slowly remove the grouting pipe.
8. The method for advanced reinforcement of water-rich tunnels as described in any one of claims 1 to 6, characterized in that, The step of spraying the cement-based slurry into the gel body through the high-pressure nozzle includes: The cement-based slurry and high-pressure airflow are respectively delivered to the high-pressure nozzle by a high-pressure pump set and an air compressor; The cement-based slurry and the high-pressure airflow are sprayed out at high speed through the high-pressure nozzle, while simultaneously cutting and mixing the gel and the surrounding soil. The nozzle is rotated and simultaneously raised to continuously spray the cement-based grout from the bottom to the top of the grouting hole.
9. The method for advanced reinforcement of water-rich tunnels as described in any one of claims 1 to 6, characterized in that, The number of grouting holes is multiple, and the multiple grouting holes are distributed in a plum blossom shape.
10. The method for advanced reinforcement of water-rich tunnels as described in any one of claims 1 to 6, characterized in that, After the step of mixing the thixotropic slurry with the geological body surrounding the grouting hole to form a gel, the method further includes: Inspection holes are drilled in the strata surrounding the tunnel; the inspection holes are spaced apart from the grouting holes. Measure the water flow rate in the inspection hole and check the water quality in the inspection hole; The impermeability of the gel is determined by the amount of water discharged and the water quality.