Tunnel high-pressure gushing water comprehensive treatment method integrating probing, guiding, blocking, discharging and fixing

Abstract

The invention discloses a tunnel high-pressure gushing water comprehensive treatment method integrating probing, guiding, blocking, discharging and fixing, and belongs to the technical field of tunnel construction. The method comprises the following steps: exploring and dividing geological subsections; drainage: drilling a water diversion hole in the concentrated water gushing channel, and pre-burying a multi-stage drainage pipe for graded pressure reduction; blocking is conducted, specifically, the channel is closed through a layered pressure backfill grouting technology; a permanent drainage system is laid, and a deep drainage pipe is connected; reinforcement is carried out, and radial consolidation grouting and groove jumping type inverted arch dismounting and replacing are carried out; and the whole process is monitored in real time, and construction is dynamically optimized. According to the method, exploration, drainage, plugging, drainage, reinforcement and dynamic regulation and control are organically combined, the problems that water plugging, pressure reduction and cooperation are difficult in high-pressure water-rich karst stratum tunnel gushing water treatment are solved, and the method has the advantages of being prominent in systematicness, thorough in treatment, remarkable in pertinence, safe, controllable, novel in process, reliable in quality, dynamic in regulation and control, high in adaptability, obvious in comprehensive benefit and the like.

Description

Technical Field

[0001] This invention relates to the field of tunnel and underground engineering construction technology, and particularly to a method for treating tunnel water inrush under karst development and high-pressure, water-rich geological conditions. Specifically, this invention provides a comprehensive method for treating high-pressure water inrush in tunnels that integrates exploration, drainage, sealing, water discharge, and reinforcement, to solve the problem of high-pressure, high-flow-rate water inrush encountered during tunnel construction. Background Technology

[0002] In the construction of tunnels for highways and railways in mountainous areas, traversing water-rich karst strata is an extremely challenging global problem. These strata typically feature well-developed joints and fissures, and are widely distributed with unfavorable geological formations such as caves, fissures, and karst conduits, forming a complex network of groundwater resources. If a high-pressure aquifer is exposed during construction, it can easily trigger catastrophic accidents such as water inrush and mudslides. These accidents not only seriously threaten the safety of construction personnel and machinery, causing severe delays in the construction period, but improper handling can also leave long-term safety hazards during tunnel operation, such as water pressure accumulation behind the lining, structural leakage, reduced load-bearing capacity, and even tunnel failure.

[0003] Currently, conventional treatment techniques for tunnel water inrush mainly include: Single-grouting water plugging method: This method uses cement grout or chemical grout to seal the water-producing fissures. However, under high pressure and high flow conditions, the grout is easily dispersed and diluted by the water flow, making it difficult to effectively gel and remain, resulting in water plugging failure and significant material waste. For large-scale karst pipes, this method is even more ineffective in forming an effective water plug.

[0004] Centralized drainage method: Pipes are directly buried at the water outlet to divert the gushing water into the tunnel drainage system. While this method can temporarily relieve the flooding, it does not reduce the water pressure in the surrounding rock, causing the lining structure to withstand high water pressure for a long period during operation, posing a structural safety risk. Furthermore, directly discharging large amounts of mineral-rich groundwater may also cause environmental problems such as a drop in the regional groundwater level.

[0005] Surface sealing and local reinforcement method: This involves sealing the surface of the constructed initial support or backfilling the local collapse area. This method often only addresses the symptoms and not the root cause, failing to solve the problem of the huge cavity and high-pressure water pocket behind the lining. Water will seek new weak points to seep out, creating a passive situation of "blocking here and leaking there".

[0006] The aforementioned traditional methods generally suffer from a common flaw: the treatment measures are singular and isolated. They often target a single symptom of the water inrush (such as the outlet) or a single aspect (such as blocking without drainage or draining without reinforcement), lacking a systematic approach that organically combines geological exploration, water pressure control, effective sealing, permanent drainage, and structural reinforcement.

[0007] Taking the Dejiang Tunnel on the Dewu Expressway as an example, the section from ZK9+896 to ZK9+968 is located in the core of the Shixiang oblique, a zone rich in and transporting groundwater. The surrounding rock in this section is Qixia Formation limestone, with highly developed joints and fissures, and multiple karst conduits. The measured stable inflow is as high as 1800 m³ / h, with high water head pressure. Under such extremely complex hydrogeological conditions, it is difficult to achieve ideal results by using only one of the above-mentioned single technologies. For example, with simple grouting, a large amount of grout will be lost with the karst conduits; with simple drainage, the long-term safety of the secondary lining cannot be guaranteed; and neglecting the replacement and reinforcement of the damaged invert arch will leave permanent structural hazards.

[0008] Therefore, those skilled in the art have long needed a comprehensive treatment technology that can systematically, precisely, and dynamically regulate the entire process of high-pressure, water-rich karst formations, in order to achieve thorough water blocking, effective drainage, and long-term structural safety while ensuring construction safety. Summary of the Invention

[0009] To address the aforementioned problems, the present invention aims to provide a comprehensive treatment method for high-pressure water inrush in tunnels that integrates exploration, diversion, blocking, drainage, consolidation, and regulation. The core of this method lies in integrating six key aspects—precise geological exploration, graded water pressure guidance, effective channel sealing, permanent drainage and pressure reduction, structural system reconstruction, and dynamic control throughout the entire process—into a logically rigorous, scientifically ordered, and feedback-optimized organic whole. This solves the problems of difficulty in blocking water, pressure reduction, coordination, high safety risks, and poor long-term effectiveness caused by the lack of systematic and comprehensive water inrush treatment measures during tunnel construction in karst-developed, high-pressure, and water-rich strata.

[0010] The objective of this invention is achieved through the following technical solution: A comprehensive treatment method for high-pressure water inrush in tunnels, integrating exploration, diversion, plugging, drainage, and reinforcement, includes the following steps: S1. Exploration: Through geological surveys and borehole exploration, the distribution of geological sub-segments and the characteristics of water inflow channels in the tunnel are identified, providing a precise basis for subsequent refined treatment.

[0011] S2. Drainage: Based on the results of the exploration steps, water inlet holes are drilled at the identified concentrated water inflow channels and multi-stage drainage pipes (including shallow water inlet pipes and deep drainage pipes) are pre-buried to actively guide the water inflow in stages, initially reduce water pressure, and establish a controllable drainage path.

[0012] S3. Sealing: After establishing a controllable drainage path through the aforementioned drainage steps, the centralized water inflow channel is sealed using a layered pressure backfilling grouting process. This process, through a bottom-up approach and dual control of pressure and grout return, ensures the formation of a dense, high-strength water-blocking body in a dynamic water environment.

[0013] S4. Drainage: While forming an effective water-stopping barrier in the sealing step, a permanent drainage system is laid simultaneously in the tunnel, and the deep drainage pipe in the multi-stage drainage pipe is connected to the system to form a long-term and stable deep pressure relief channel, realizing "combination of sealing and drainage, using drainage to ensure reinforcement".

[0014] S5. Reinforcement: After completing the sealing and drainage steps to eliminate the dominant factors of water damage, radial consolidation grouting based on the geological sub-segment differentiation is carried out on the water-rushing section, and the damaged invert arch is replaced and rebuilt in a slot-like manner, thereby fully restoring and improving the overall bearing capacity and stability of the tunnel structure.

[0015] S6. Regulation: As a comprehensive guarantee and optimization measure, real-time monitoring and measurement are implemented throughout the entire process of drainage, sealing, water drainage and reinforcement. Based on the dynamic analysis of data such as structural deformation, internal force, water pressure and grouting parameters, the treatment effect and structural status are evaluated, and the subsequent construction parameters and process sequence are dynamically optimized accordingly to achieve information-based and intelligent dynamic construction management.

[0016] Furthermore, in step S1, based on the degree of development of joints and fissures in the surrounding rock revealed by the borehole, the presence of karst conduits, and the water inflow, the water inflow section is precisely divided into a stable section with relatively developed joints and fissures, a fractured section with broken rock mass, and a concentrated water inflow section with karst conduits, thus realizing the basis for differentiated treatment design of "one policy for each section".

[0017] Further, in step S3, the layered pressure backfilling grouting specifically involves: after sealing the water inflow point, backfilling grouting is carried out layer by layer from bottom to top. When the grouting pressure of a single layer reaches a predetermined value (e.g., 0.5 MPa) or when grout is observed to return from the pre-embedded water pipe in the upper layer, the grouting of that layer is stopped. After the strength reaches the standard, the next layer is backfilled. This cycle is repeated until the backfilling reaches the designed height (e.g., 6 meters above the top arch), ensuring that the filling is dense and forms an effective water-blocking curtain.

[0018] Furthermore, in step S6, the real-time monitoring and measurement throughout the entire process specifically includes monitoring tunnel structural deformation (such as arch subsidence and perimeter convergence), internal forces of the support structure (such as anchor bolt axial force and steel frame stress), water inflow pressure and flow rate, and grouting parameters, and establishing a three-level early warning mechanism (such as normal, yellow warning, and red alert). When the monitoring data triggers an early warning, a predetermined feedback adjustment procedure is immediately initiated: construction parameters are adjusted during a yellow warning; construction is suspended during a red alert for special analysis to ensure that construction is always in a safe and controllable state.

[0019] Furthermore, the dynamic optimization includes: adjusting the arrangement of water inlet holes based on drainage data during the drainage stage; adjusting the grout performance and grouting process in real time based on grouting feedback during the sealing stage; and adjusting the grouting pressure and replacement scheme based on deformation data during the reinforcement stage.

[0020] Compared with existing technologies, the integrated treatment method for high-pressure water inrush in tunnels, which combines exploration, diversion, blocking, drainage, and reinforcement, provided by this invention has the following significant advantages: (1) Systematic approach and thorough treatment: The method integrates the six major steps of "exploration, drainage, sealing, water supply, reinforcement and regulation" to form a comprehensive solution with a closed-loop logic. This method not only solves the immediate problem of water inrush, but also eliminates long-term water pressure through permanent drainage and restores the structural system through comprehensive reinforcement, thus achieving a leap from "temporary water stoppage" to "fundamental treatment". The treatment effect is thorough and lasting.

[0021] (2) Targeted and safe: Based on the detailed geological sub-section division, differentiated treatment measures are implemented (such as the dense arrangement of grouting holes and the setting of multi-stage drainage pipes). In particular, the process sequence of "first introduce, then drain, reduce pressure and then plug" fundamentally solves the problem of high-pressure dynamic water plugging, and greatly improves the success rate of plugging operation and construction safety.

[0022] (3) Novel process and reliable quality: The “layered pressure backfill grouting process” effectively ensures the density of grouting in complex cavities and the integrity of water plugs through the construction method of bottom-up and dual control of pressure and grout return, avoiding the common quality problems of ineffective grout loss or incomplete sealing.

[0023] (4) Dynamic regulation and strong adaptability: Through real-time monitoring and dynamic feedback mechanism, the treatment process can be dynamically regulated according to the geological conditions and the actual response of the structure, which greatly enhances the adaptability of the method to complex and variable geological conditions and the accuracy of treatment.

[0024] (5) Significant comprehensive benefits: Although the initial investment may include systematic monitoring and control costs, this method avoids the huge costs of repeated emergency repairs and subsequent remediation through a single systematic treatment, and shortens the total construction period. At the same time, by effectively controlling groundwater discharge and ensuring the long-term safety of the structure, the potential impact on the environment is reduced, and operational safety is guaranteed, resulting in significant comprehensive economic and social benefits. Attached Figure Description

[0025] Figure 1 This is a flowchart of the comprehensive treatment method for high-pressure water inrush in tunnels according to the present invention. Detailed Implementation

[0026] To make the objectives, technical solutions, and advantages of this invention clearer, the implementation methods of this invention will be described in detail below with reference to specific engineering embodiments. This embodiment takes the high-pressure water inrush treatment project of the left tunnel section ZK9+896~ZK9+968 of the Dejiang Tunnel on the Dewu Expressway in Guizhou Province as the background to illustrate the specific application of the method of this invention. It should be noted that the specific embodiments described herein are only for explaining this invention and are not intended to limit this invention. Example: Comprehensive treatment of the high-pressure, water-rich karst section from ZK9+896 to ZK9+968 in the left tunnel of Dejiang Tunnel

[0027] The ZK9+896~ZK9+968 section of the left tunnel of Dejiang Tunnel is located in the core of the Shixiang oblique, with Permian Qixia Formation (P2q) limestone as the surrounding rock. This section is a zone of groundwater enrichment and migration, with highly developed joints and fissures, and karst conduits. During construction, a large-scale high-pressure water inrush occurred, with a measured stable inrush volume as high as 1800 m³ / h. The enormous water pressure caused severe deformation of the initial support and heave and cracking of the invert arch. Since traditional single grouting or drainage methods were ineffective, the comprehensive treatment method for high-pressure water inrush in tunnels, integrating exploration, diversion, blocking, drainage, and reinforcement, as described in this invention, was adopted.

[0028] The comprehensive treatment method for high-pressure water inrush in tunnels follows the principles of "exploration first, diversion before drainage, combination of blocking and drainage, reinforcement and strengthening, and full-process control," and is implemented in the following steps: S1. Exploration: Refined Geological Sub-section Division S11. Exploration methods: Geological forecasting and analysis will be conducted based on the comprehensive excavation findings, supplementary geological boreholes, and the "Technical Specification for Geological Forecasting in Highway Tunnel Construction" (DB42 / T 561-2009).

[0029] S12. Information Recording: Record in detail the depth, lithology, fracture development, location of water inflow points, water pressure, flow rate, and voiding within each exploratory borehole, forming a systematic geological archive.

[0030] S13. Sub-segment division: Based on the exploration results, the 72m long water inrush section was precisely divided into three geological sub-segments, providing accurate targets for differentiated treatment: Concentrated water inflow section (ZK9+928~ZK9+958): 30m in length. This section has well-developed karst features, with obvious caves and karst conduits, which are the main source of the total water inflow (accounting for more than 70%). The water pressure is high, and the surrounding rock has extremely poor self-stabilizing ability.

[0031] The fractured section (ZK9+924~ZK9+928, ZK9+958~ZK9+968) is 14m long. The rock mass is fractured with well-developed joints and fissures, mainly characterized by seepage water, and the surrounding rock has poor self-stabilizing ability.

[0032] Stable section (ZK9+896~ZK9+924): 28m in length. The surrounding rock is relatively intact, with well-developed joints and fissures, and is mainly characterized by moist or linear water flow.

[0033] S2. Drainage: Staged water diversion and active pressure reduction S21. Target positioning: Focus on the "concentrated water inflow section" designated in S1, especially the main water outlets that have been exposed, such as ZK9+941 and ZK9+951.

[0034] S22. Pre-embedded multi-stage drainage pipes: Deep drainage pipe: A 108mm diameter water inlet hole is drilled at the center of the main water outlet, extending at least 8m into the karst pipe or high-pressure water-bearing fissure. A steel perforated pipe with a reverse filter layer is buried as the deep drainage pipe, and a high-pressure valve is installed at the pipe opening to connect to a large-capacity temporary drainage system. This system is specifically designed for draining deep, high-pressure water, achieving active and controllable pressure reduction.

[0035] Shallow water intake pipe: Multiple steel pipes with a diameter of 42mm are laid in a ring around the deep drainage pipe as shallow water intake pipes, with a depth of 3-4m, to guide and collect fissure water around the pipe.

[0036] S23. Implementation effect: By opening the deep drainage pipe valve, the concentrated water flow is discharged in an organized manner. The measured water pressure at the key point dropped from the initial 2.5MPa to below 0.8MPa, effectively transforming the dynamic water environment into a stagnant or low-speed flow condition that is conducive to sealing.

[0037] S3. Sealing: Layered pressure backfill grouting S31. Grouting material: PO 42.5 ordinary Portland cement is used to prepare the grout, with a water-cement ratio ranging from 0.8:1 to 1:1. For locations with high flow rates, 3% quick-setting agent (water glass) or special nano-water-blocking material is added to the grout to improve its erosion resistance and early strength.

[0038] S31. Implementation of layered pressure backfilling grouting process: S311. Sealing of water inflow points: First, quickly and mechanically seal the outlet of the karst pipe to force the water flow to be completely discharged from the pre-buried drainage pipe system.

[0039] S312. Bottom-up layered grouting: Start the first layer of backfill grouting from the bottom of the identified cavity or pipe. Set the initial grouting pressure to the current hydrostatic pressure (approximately 0.8 MPa) plus 0.2 MPa.

[0040] S313. Dual-control stop criteria: Dual-control stop criteria: Strict monitoring during grouting. When the grouting pressure of the layer steadily rises to 0.5MPa, or when cement slurry is observed to continuously flow out of the shallow water pipe pre-embedded in the upper layer (return slurry), it is determined that the layer is filled densely, and grouting of the layer is stopped immediately.

[0041] S314. Waiting for curing cycle: After the cement grout of this layer has solidified and reached the design strength (about 75%), the drilling and grouting of the next layer is carried out, and the above process is repeated.

[0042] S315. Grouting Scope and Final Pressure: Backfilling is carried out layer by layer from bottom to top until the filling material reaches a height of 6 meters above the tunnel arch, forming an effective water-stopping curtain. The final grouting pressure shall not be less than 4 MPa to ensure the compactness and long-term impermeability of the filling material.

[0043] S4. Drainage: Construct a permanent pressure relief system S41. System Laying: Φ300mm HDPE double-wall corrugated pipes are laid as permanent drainage mains under the shoulders on both sides of the tunnel, with a longitudinal slope of not less than 0.5%. A sedimentation basin and connecting drainage ditches are constructed in the nearby No. 4 vehicular cross passage to form a complete drainage network.

[0044] S42. System Connection: The deep drainage pipe pre-buried in step S2 is permanently connected to the above-mentioned drainage system through a pressure reducing valve and matching fittings, forming a long-term, stable pressure relief channel for deep water levels. After confirming that there is no water flow in the shallow water inlet pipe, grouting is performed to seal the hole.

[0045] S5. Reinforcement: Structural System Reconstruction S51 Radial Consolidation Grouting: Radial grouting holes are arranged throughout the tunnel circumference (arch and wall), generally with a circumferential spacing of 1.5m and a longitudinal spacing of 2.0m, with a hole depth of 4m. Differential and denser arrangements are implemented: in the concentrated water inflow sections and fractured sections designated in S1, the circumferential spacing of the grouting holes is increased to 1.0m, and the longitudinal spacing to 1.5m, for focused reinforcement, improving the integrity and bearing capacity of the surrounding rock.

[0046] S52. Inverted arch-style skip-slot replacement: Pre-removal verification: Based on the exploration data of S1, verification boreholes are arranged at certain intervals in the section of the invert arch to be replaced (such as ZK9+896~ZK9+955) to drill in an area of ​​no less than 6m below the bottom of the invert arch to confirm that there are no hidden cavities or water-rich bodies, and to ensure the safety of the replacement construction.

[0047] Skip-slot construction: The long invert section to be replaced is divided into several short slots (e.g., each 4m). Construction strictly follows the skip-slot sequence: first, the slots numbered 1, 4, 7… are constructed at intervals; after the concrete strength of these slots reaches the design requirements, the slots numbered 2, 5, 8… are constructed, and so on. This method maximizes the maintenance of temporary supports at the tunnel bottom, preventing overall instability.

[0048] S6. Regulation: Dynamic management throughout the entire process This step serves as a comprehensive safeguard system and is implemented throughout the entire process from S2 to S5.

[0049] S61. Monitoring Network Deployment: Establish a comprehensive monitoring system that includes tunnel structural deformation (arch settlement, perimeter convergence), internal forces of support structure (steel frame stress, concrete strain), water environment (pressure and flow rate at water inflow points), and grouting process parameters (pressure, flow rate).

[0050] S62. Three-level early warning and response mechanism: Quantitative early warning thresholds should be set. For example, a yellow warning is triggered when the daily settlement rate of the arch crown exceeds 3 mm or the convergence rate exceeds 2 mm. In this case, construction parameters need to be adjusted, such as reducing the grouting rate and strengthening temporary supports. A red alarm is triggered when the daily settlement rate of the arch crown exceeds 5 mm or the stress of the support structure reaches 80% of the design allowable value. Construction must be immediately suspended, personnel evacuated, and a special assessment by a technical expert group is required before work can resume.

[0051] S63. Dynamic Optimization Decision-Making: In step S2, the number and angle of the water inlet holes are dynamically adjusted based on the real-time flow data of each drain pipe to optimize the pressure reduction effect.

[0052] In the sealing stage of step S3, the grout ratio is dynamically adjusted (e.g., from thin to thick) or an intermittent grouting process is adopted based on the real-time feedback of grouting pressure and flow rate to cope with the grout consumption of the large channel.

[0053] In step S5, during the reinforcement stage, the length of the jump groove and the support scheme are dynamically adjusted based on the convergence monitoring data during the replacement of the invert arch to ensure construction safety.

[0054] Through the aforementioned systematic treatment, the water inrush in the ZK9+896~ZK9+968 section of the Dejiang Tunnel was effectively controlled, the initial support was stable, and the secondary lining construction proceeded smoothly without any further water inrush or mudslide hazards. Monitoring data showed that the water pressure behind the lining was significantly reduced, the structural deformation tended to stabilize, and the treatment effect met the design and operational safety requirements.

[0055] This embodiment demonstrates the specific application of the method of the present invention in complex karst high-pressure water-rich tunnels, reflecting the systematic treatment concept of "exploration, diversion, blocking, drainage, consolidation, and regulation" in six aspects. Through precise geological exploration, graded water pressure guidance, layered sealing of the passage, permanent drainage and pressure reduction, structural system reinforcement, and dynamic control throughout the entire process, safe, thorough, and long-term treatment of high-pressure water inrush sections is achieved.

[0056] This invention is not limited to the above embodiments. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this invention should be included within the scope of protection of this invention.

[0057] The above embodiments demonstrate that the method provided by this invention is a logically rigorous, clearly defined, and highly effective systematic solution with extremely high engineering application value. Modifications and adjustments made by those skilled in the art within the principles and spirit of this invention should be considered to fall within the protection scope of this invention.

[0058] Other aspects of this invention that are not detailed herein are all conventional techniques known to those skilled in the art.

[0059] It should be noted that the terms “comprising,” “including,” or any other variations 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.

[0060] The scope of protection of this invention is not limited to the technical solutions disclosed in the specific embodiments. Any modifications, equivalent substitutions, improvements, etc., made to the above embodiments based on the technical essence of this invention shall fall within the scope of protection of this invention.

Claims

1. A comprehensive treatment method for high-pressure water inrush in tunnels that integrates exploration, diversion, blocking, drainage, and reinforcement, characterized in that: Includes the following steps: S1. Exploration: Through geological surveys and borehole exploration, determine the distribution of geological sub-segments and the characteristics of water inflow channels in the tunnel; S2. Drainage: Based on the results of the exploration steps, water inlet holes are drilled and multi-stage drainage pipes are pre-buried at the identified concentrated water inflow channels to guide and reduce water pressure in stages. S3. Sealing: After establishing a controllable drainage path by completing the above drainage steps, the centralized water inflow channel is sealed by a layered pressure backfilling grouting process; S4. Drainage: While forming an effective water-stopping barrier in the sealing step, a permanent drainage system is laid in the tunnel, and the deep drainage pipe in the multi-stage drainage pipe is connected to it to form a long-term drainage path; S5. Reinforcement: After completing the sealing and drainage steps to eliminate the dominant factors of water damage, radial consolidation grouting is carried out on the water inrush section and the damaged invert arch is replaced in a slot-type manner to rebuild the tunnel structure system. S6. Control: Throughout the entire process of drainage, sealing, and reinforcement, real-time monitoring and measurement are implemented. The treatment effect and structural status are dynamically evaluated based on the monitoring data, and subsequent construction parameters and procedures are dynamically optimized accordingly.

2. The comprehensive treatment method for high-pressure water inrush in tunnels according to claim 1, characterized in that: In step S1, based on the degree of development of joints and fissures in the surrounding rock revealed by the borehole, the presence of karst conduits, and the water inflow, the water inflow section is precisely divided into a stable section with relatively developed joints and fissures, a fractured section with broken rock mass, and a concentrated water inflow section with karst conduits.

3. The comprehensive treatment method for high-pressure water inrush in tunnels according to claim 2, characterized in that: In step S2, the pre-buried multi-stage drainage pipes include a water inlet pipe for controlling shallow water flow and a deep drainage pipe with a depth of not less than 8 meters for controlling deep high-pressure water inrush.

4. The comprehensive treatment method for high-pressure water inrush in tunnels according to claim 3, characterized in that: In step S3, the layered pressure backfill grouting is specifically carried out as follows: after sealing the water inflow point, backfill grouting is carried out layer by layer from bottom to top. When the grouting pressure of a single layer reaches 0.5MPa or when grout is observed to return from the upper water inlet pipe, the grouting of that layer is stopped. After the strength meets the standard, the next layer is backfilled until the backfilling reaches 6 meters above the top arch.

5. The comprehensive treatment method for high-pressure water inrush in tunnels according to claim 2, characterized in that: In step S5, when radial consolidation grouting is performed on the water inflow section, the grouting holes are arranged based on the geological sub-sections defined in the exploration step, and a denser arrangement is adopted in the concentrated water inflow section and the fractured section.

6. The comprehensive treatment method for high-pressure water inrush in tunnels according to claim 1, characterized in that: In step S4, the permanent drainage system includes a Φ30 drainage pipe laid below the tunnel surface and a sedimentation tank and a central drainage ditch set in the cross passage to ensure that the drainage capacity is greater than the stable inflow of water in the section.

7. The comprehensive treatment method for high-pressure water inrush in tunnels according to claim 1, characterized in that: In step S5, when replacing the damaged invert arch in a skip-slot manner, before construction, the bottom of the invert arch must be drilled to a depth of not less than 6 meters based on the drilling data from the exploration step, and the skip-slot sequence should be used during the replacement.

8. The comprehensive treatment method for high-pressure water inrush in tunnels according to claim 1, characterized in that: In step S6, the real-time monitoring and measurement of the entire process specifically includes monitoring the deformation of the tunnel structure, the internal force of the support structure, the water inflow pressure and flow rate, and the grouting parameters, and establishing a three-level early warning mechanism; when the monitoring data triggers a yellow warning, the construction parameters are adjusted; when a red warning is triggered, construction is suspended and a special analysis is conducted.

9. The comprehensive treatment method for high-pressure water inrush in tunnels according to claim 8, characterized in that: The yellow warning threshold of the three-level early warning mechanism includes a daily settlement rate of the arch greater than 3 mm or a perimeter convergence rate greater than 2 mm, and the red warning threshold includes a daily settlement rate of the arch greater than 5 mm or the stress of the support structure reaching 80% of the design allowable value.

10. The comprehensive treatment method for high-pressure water inrush in tunnels according to claim 9, characterized in that: The dynamic optimization of subsequent construction parameters and procedures includes: In step S2, the number, depth, or angle of the water inlet holes are dynamically adjusted based on the flow rate and pressure data of the drain pipe. In step S3, the grout mix ratio and grouting rate are adjusted in real time or an intermittent grouting process is adopted based on the feedback of grouting pressure and flow rate. In step S5, the pressure and sequence of radial grouting or the skip length and support scheme for invert arch replacement are dynamically adjusted based on structural deformation monitoring data.

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