Magnetic anchoring grading grouting plugging method based on tunnel large-flow high-flow-speed sudden gushing water

Abstract

The invention provides a magnetic anchoring grading grouting plugging method based on tunnel large-flow high-flow-speed sudden gushing water. The method comprises the steps that a magnetic control system generates a controllable magnetic field through an electromagnetic-permanent magnet composite base; the magnetic anchoring anti-impact framework is formed by iron ore aggregate with specific gradation; the grouting system realizes graded grouting through double grouting pipes; the monitoring system monitors flow velocity, pressure and grouting parameters in real time through a sensor. During implementation, the electromagnetic-permanent magnet composite base is installed and filled with graded aggregate to form a magnetic adsorption framework, then the water flow system is started to simulate the sudden water gushing working condition, then low-pressure permeation grouting is conducted through the short grouting pipe to fill framework pores, high-pressure grouting is conducted through the long grouting pipe to form a surface sealing layer, and the surface sealing layer is sealed. And finally regulating the magnetic field intensity and evaluating the plugging performance. A complete plugging system penetrating from inside to surface sealing is realized by adopting a graded grouting process; construction efficiency and long-term safety are both considered through intelligent magnetic field regulation and control; and the engineering applicability of emergency plugging is improved.

Description

Technical Field

[0001] This invention relates to the field of waterproofing and water control technology in underground engineering, and in particular to a magnetic anchor-based graded grouting sealing method for large-flow, high-velocity sudden water inrush in tunnels. Background Technology

[0002] During tunnel and underground engineering construction, when traversing water-rich faults, karst development zones, or loose aquifers, sudden water inrush disasters with high flow rates, high pressure, and high velocities are highly likely. These disasters are characterized by their suddenness, large volume, and high impact force. Traditional grouting sealing techniques often fail or are ineffective due to problems such as the cement-based grout being diluted and dispersed by high-speed water flow and the difficulty in quickly stabilizing the skeleton structure. In existing technologies, conventional aggregate filling combined with grouting methods suffer from defects such as weak skeleton erosion resistance, low cement-based grout retention rate, and insufficient compactness of the sealing body; while single grouting materials are prone to loss in dynamic water environments, making it difficult to form an effective water barrier. In addition, existing water inrush sealing processes often rely on complex mechanical fixation or long-term manual operation, which is difficult to meet the timeliness requirements of emergency rescue. Although some studies have used magnetic materials to assist grouting, there is still a lack of systematic methods for high flow rate and high velocity conditions, especially in terms of magnetic control, graded aggregate optimization, and multi-stage grouting process coordination. Therefore, there is an urgent need for a sealing method that can respond quickly, adapt to dynamic water environments, and achieve long-term sealing. Summary of the Invention

[0003] This invention addresses the technical challenges of sealing tunnels with large-flow, high-velocity sudden water inrushes, such as insufficient skeleton stability, easy erosion and loss of cement-based grout by water flow, poor sealing body density, and slow emergency response. It provides a sealing method based on the synergy of magnetic anchoring and graded grouting, achieving rapid and stable sealing and long-term sealing in dynamic water environments.

[0004] To achieve the above-mentioned technical features, the objective of this invention is as follows: A magnetic anchoring and grading grouting sealing method based on high-flow-rate, high-velocity sudden water inrush in tunnels, comprising the following steps: Step 1: Based on the size of the water inrush tunnel opening and the water flow conditions, select and install a magnet base composed of electromagnetic and permanent magnet composites below the water inrush tunnel opening, and set the initial magnetic field strength; fill the pre-installed pipes with graded iron ore aggregate to form a magnetic adsorption skeleton; install a dual grouting pipe system and connect the grouting equipment and the data monitoring system. Step 2: Start the water flow simulation system, adjust the water pump and pressure control valve to make the flow rate and water pressure reach the target sudden water inrush condition; verify the flow field stability and the skeleton's anti-scouring performance through high-speed camera and flow velocity sensor; Step 3: Inject cement-based grout at low pressure through a short grouting pipe, controlling the grouting pressure to be lower than the impact force of the water flow, so that the cement-based grout slowly seeps out from the micropores and penetrates into the pores of the iron ore skeleton; Simultaneously monitor the diffusion pattern of the cement-based grout and the filling of the pores in the skeleton until the cement-based grout has completely penetrated and initially cemented. Step 4: Switch to the long grouting pipe for secondary high-pressure grouting. The grouting pressure is higher than the pressure of the sudden water inrush, so that the cement-based grout covers the water-facing side of the skeleton and fills the contact gap between it and the surrounding rock; record the grouting pressure, the thickness of the cement-based grout coverage, and the interface formation process. Step 5: After grouting is completed, gradually reduce the magnetic field strength to the off state to simulate the structural stability after demagnetization; allow it to stand for curing until the cement-based grout is completely solidified, and measure the density and impermeability of the sealing body using an ultrasonic tester and a permeameter.

[0005] Preferably, the sealing body rapidly forms a stable skeleton in a dynamic water environment using magnetized iron ore aggregate, and then uses a dual grouting pipe system for infiltration grouting and surface coating to achieve a transition from temporary stability to permanent sealing. Furthermore, through the synergistic mode of "magnetic anchoring-grout infiltration", it adapts to engineering environments with high flow rates and high water pressure.

[0006] Preferably, the magnet base and the pre-installed pipe adopt a modular design that allows for quick connection and expansion, and can be flexibly assembled according to the actual size and location of the sudden water inlet to meet the timeliness requirements of emergency sealing.

[0007] Preferably, the iron ore aggregate adopts a mass ratio gradation of small particle size 0-4.75mm: medium particle size 4.75-9.5mm: large particle size 9.5-13.2mm = 20%-25%: 50%-55%: 20%-25%, to achieve the densest packing of the aggregate under magnetic force, forming a skeleton structure with low porosity, high stability, and good penetration of cement-based slurry.

[0008] Preferably, the diameter and spacing of the holes in the short grouting pipe are set in a certain proportion to achieve low-pressure, slow-speed, and uniform seepage of the cement-based grout, avoid it being washed away in high-speed water flow, and ensure that the cement-based grout can fully penetrate and cement the pores in the iron ore skeleton.

[0009] Preferably, the outlet of the long grouting pipe is located on the water-facing side of the skeleton for secondary grouting. The grouting pressure is greater than the pressure of the sudden water inrush, ensuring that the cement-based grout can effectively cover the surface of the primary sealing body and fill the contact gap between it and the surrounding rock, forming a high-strength, highly impermeable reinforced sealing interface.

[0010] Preferably, the sealing body adopts a pre-installed pipeline and graded aggregate composite system, which can effectively adapt to the deformation of the surrounding rock and the pulsating water pressure through elastic deformation, thereby adapting to complex environments and forming a long-term sealing effect.

[0011] Preferably, the magnet base adopts a composite design of electromagnet and permanent magnet, and the magnetic field strength can be steplessly adjusted and quickly started and stopped through an external power controller.

[0012] Preferably, the magnet base provides a strong magnetic field during the aggregate filling stage to quickly stabilize the skeleton, and reduces or turns off the magnetic field after grouting is completed to avoid long-term magnetic interference to subsequent tunnel operations and testing equipment.

[0013] The present invention has the following beneficial effects: 1. This invention utilizes a controllable magnetic field generated by an electromagnetic-permanent magnet composite base to rapidly form a high-strength, erosion-resistant skeleton from graded iron ore aggregate at the entrance of a sudden water inrush. This skeleton, tightly connected by magnetic adsorption, effectively resists the severe erosion of high-velocity water flow, overcoming the technical challenge of traditional aggregates being easily dispersed in dynamic water environments. This provides a stable and reliable support foundation for subsequent grouting operations, significantly improving the success rate of sealing construction.

[0014] 2. A unique dual-grouting pipe system is employed to achieve staged grouting. First, low-pressure, slow grouting is carried out through short grouting pipes with micropores, allowing the cement-based grout to fully penetrate and fill the internal pores of the framework, forming a dense internal structure. Then, high-pressure grouting is performed through long grouting pipes, forming a high-strength, impermeable sealing layer on the water-facing side of the framework, completely filling the contact gaps between it and the surrounding rock. This achieves dual sealing protection from the inside out, significantly improving the integrity and durability of the sealing body.

[0015] 3. An optimized iron ore aggregate gradation with a specific mass ratio (small:medium:large = 20-25%:50-55%:20-25%) is adopted, which enables the densest packing under magnetic force, forming a skeleton structure with low porosity and high stability. This gradation design ensures the mechanical stability of the skeleton while providing suitable channels for cement-based grout penetration, giving the sealing body both good compressive strength and impermeability, greatly extending the service life of the sealing body.

[0016] 4. Through a composite design of electromagnets and permanent magnets, coupled with an external controller, stepless adjustment of magnetic field strength and rapid start-stop functionality are achieved. A strong magnetic field is provided during the aggregate filling stage to ensure rapid stabilization of the framework, while the magnetic field can be reduced or shut off after grouting. This ensures efficiency in the construction process while avoiding magnetic interference with subsequent tunnel operations and testing equipment, achieving a balance between construction safety and project efficiency.

[0017] 5. Adopting a modular design concept, the entire sealing system possesses the ability to be quickly connected and expanded, allowing for flexible assembly based on the actual size and location of the sudden water inrush. Combined with a pre-installed pipeline and graded aggregate composite system, it effectively adapts to changes in surrounding rock deformation and pulsating water pressure. This significantly improves the response speed and processing efficiency of emergency sealing, meeting sealing needs under various complex working conditions and demonstrating broad engineering applicability. Attached Figure Description

[0018] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0019] Fig. 1 This is a schematic diagram of the overall structure of the device of the present invention.

[0020] Fig. 2 This is a schematic diagram of the structure and working principle of the dual grouting pipe system.

[0021] In the diagram: 1. Water inrush inlet; 2. Foundation; 3. Iron ore aggregate; 4. Pre-installed pipe; 5. Grouting equipment; 6. Data monitoring system; 7. Short grouting pipe; 8. Cement-based grout; 9. Micropores; 10. Long grouting pipe; 11. Interface. Detailed Implementation The present invention will be further described in detail below through specific embodiments. These embodiments are intended to enable those skilled in the art to gain a more comprehensive understanding of the present invention, but do not limit the invention in any way.

[0022] Example 1: like Figs. 1-2 As shown, a magnetic anchoring and grading grouting sealing method based on high-flow-rate, high-velocity sudden water inrush in tunnels includes the following steps: Step 1: Based on the size of the water inrush tunnel 1 and the water flow conditions, select and install the electromagnetic-permanent magnet composite base 2 below the water inrush tunnel 1, and set the initial magnetic field strength; fill the pre-installed pipe 4 with graded iron ore aggregate 3 (mixed in a mass ratio of small:medium:large = 20-25%:50-55%:20-25%) to form a magnetic adsorption skeleton; install a dual grouting pipe system (short pipe microporous structure, long pipe outlet facing the water-facing side), and connect the grouting equipment 5 and the data monitoring system 6; Step 2: Start the water flow simulation system, adjust the water pump and pressure control valve to make the flow rate and water pressure reach the target sudden water inrush condition; verify the flow field stability and the skeleton's anti-scouring performance through high-speed camera and flow velocity sensor; Step 3: Inject cement-based grout 8 under low pressure through short grouting pipe 7, controlling the grouting pressure to be lower than the impact force of water flow, so that cement-based grout 8 slowly seeps out from micropores 9 and penetrates into the pores of iron ore skeleton; Simultaneously monitor the diffusion pattern of cement-based grout 8 and the filling of pores in the skeleton until cement-based grout 8 has completely penetrated and initially cemented. Step 4: Switch to the long grouting pipe 10 for secondary high-pressure grouting. The grouting pressure is higher than the pressure of the sudden water inrush, so that the cement-based grout 8 covers the water-facing surface of the skeleton and fills the contact gap between it and the surrounding rock; record the grouting pressure, the thickness of the cement-based grout coverage, and the formation process of the interface 11. Step 5: After grouting is completed, gradually reduce the magnetic field strength to the off state to simulate the structural stability after demagnetization; allow static curing until the cement-based grout 8 is completely solidified, and measure the density and impermeability of the sealing body using an ultrasonic tester and a permeameter.

[0023] Furthermore, the sealing body rapidly forms a stable framework in a dynamic water environment using magnetized iron ore aggregate 3, followed by infiltration grouting and surface coating using a dual grouting pipe system, achieving a transition from temporary stabilization to permanent sealing. This synergistic "magnetic anchoring-grout infiltration" mode is suitable for engineering environments with high flow rates and high water pressure.

[0024] Furthermore, the magnet base 2 and the pre-installed pipe 4 adopt a modular design that allows for quick connection and expansion, and can be flexibly assembled according to the actual size and location of the sudden water inlet 1 to meet the timeliness requirements of emergency sealing.

[0025] Furthermore, the iron ore aggregate 3 adopts a specific mass ratio gradation optimization of small particle size (0-4.75mm): medium particle size (4.75-9.5mm): large particle size (9.5-13.2mm) = 20%-25%: 50%-55%: 20%-25%, to achieve the densest packing of the aggregate under magnetic force, forming a skeleton structure with low porosity, high stability, and good penetration of cement-based slurry.

[0026] Furthermore, the diameter and spacing of the holes in the short grouting pipe 7 are set in a certain proportion to achieve low-pressure, slow-speed, and uniform seepage of the cement-based grout, effectively preventing it from being dispersed in high-speed water flow, and ensuring that the cement-based grout 8 can fully penetrate and cement the pores in the iron ore skeleton.

[0027] Furthermore, the outlet of the long grouting pipe 10 is located on the water-facing side of the skeleton for secondary grouting. The grouting pressure is greater than the pressure of the sudden water inrush, ensuring that the cement-based grout 8 can effectively cover the surface of the primary sealing body and fill the contact gap between it and the surrounding rock, forming a high-strength, highly impermeable reinforced sealing interface.

[0028] Furthermore, the sealing body adopts a pre-installed pipe 4 and a graded aggregate composite system, which can effectively adapt to the deformation of the surrounding rock and the pulsating water pressure through elastic deformation, thereby adapting to complex environments and forming a long-term sealing effect.

[0029] Furthermore, the magnet base 2 adopts a composite design of electromagnet and permanent magnet, and the magnetic field strength can be steplessly adjusted and quickly started and stopped through an external power controller. A strong magnetic field is provided during the aggregate filling stage to quickly stabilize the skeleton, and the magnetic field is reduced or turned off after grouting to avoid long-term magnetic interference to subsequent tunnel operations and testing equipment.

[0030] Although the preferred embodiments of the present invention have been described above in conjunction with the accompanying drawings, the present invention is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many specific modifications under the guidance of the present invention without departing from the spirit of the invention and the scope of protection of the claims, and these modifications all fall within the scope of protection of the present invention.

Claims

1. A magnetic anchoring and grading grouting sealing method based on high-flow-rate, high-velocity sudden water inrush in tunnels, characterized in that, Includes the following steps: Step 1: Based on the size of the water inrush tunnel (1) and the water flow conditions, select and install a magnet base (2) composed of electromagnetic and permanent magnet composites below the water inrush tunnel (1) and set the initial magnetic field strength; fill the pre-installed pipe (4) with graded iron ore aggregate (3) to form a magnetic adsorption skeleton; install a double grouting pipe system and connect the grouting equipment (5) and the data monitoring system (6); Step 2: Start the water flow simulation system, adjust the water pump and pressure control valve to make the flow rate and water pressure reach the target sudden water inrush condition; verify the flow field stability and the skeleton's anti-scouring performance through high-speed camera and flow velocity sensor; Step 3: Inject cement-based grout (8) under low pressure through short grouting pipe (7), and control the grouting pressure to be lower than the impact force of water flow, so that cement-based grout (8) slowly seeps out from micropores (9) and penetrates into the pores of iron ore skeleton; Simultaneously monitor the diffusion pattern of cement-based grout (8) and the filling status of pores in skeleton until cement-based grout (8) completely penetrates and initially cements. Step 4: Switch to the long grouting pipe (10) for secondary high-pressure grouting. The grouting pressure is higher than the pressure of the sudden water inrush, so that the cement-based grout (8) covers the water-facing surface of the skeleton and fills the gap between it and the surrounding rock. Record the grouting pressure, the thickness of the cement-based grout coverage and the formation process of the interface (11). Step 5: After grouting is completed, gradually reduce the magnetic field strength to the off level to simulate the structural stability after demagnetization; allow static curing until the cement-based grout (8) is completely solidified, and measure the density and impermeability of the sealing body using an ultrasonic tester and a permeameter.

2. The magnetic anchoring and grading grouting sealing method based on high-flow-rate, high-velocity sudden water inrush in tunnels according to claim 1, characterized in that: The sealing body rapidly forms a stable skeleton in a dynamic water environment by using magnetized iron ore aggregate (3). Then, it uses a dual grouting pipe system for infiltration grouting and surface coating to achieve the transition from temporary stability to permanent sealing. In turn, through the synergistic mode of "magnetic anchoring-grout infiltration", it adapts to the engineering environment of high flow rate and high water pressure.

3. The magnetic anchoring and grading grouting sealing method based on high-flow-rate, high-velocity sudden water inrush in tunnels according to claim 1, characterized in that: The magnet base (2) and the pre-installed pipe (4) adopt a modular design that can be quickly connected and expanded. They can be flexibly assembled according to the actual size and location of the sudden water inlet (1) to meet the timeliness requirements of emergency sealing.

4. The magnetic anchoring and grading grouting sealing method based on high-flow-rate, high-velocity sudden water inrush in tunnels according to claim 1, characterized in that: The iron ore aggregate (3) adopts a mass ratio gradation of small particle size 0-4.75mm: medium particle size 4.75-9.5mm: large particle size 9.5-13.2mm = 20%-25%: 50%-55%: 20%-25%, which realizes the most compact packing of aggregate under magnetic force, forming a skeleton structure with low porosity, high stability and good cement-based slurry penetration.

5. The magnetic anchoring and grading grouting sealing method based on high-flow-rate, high-velocity sudden water inrush in tunnels according to claim 1, characterized in that: The diameter and spacing of the holes in the short grouting pipe (7) are set in a certain proportion to achieve low-pressure, slow-speed and uniform seepage of cement-based grout, avoid being washed away in high-speed water flow, and ensure that cement-based grout (8) can fully penetrate and cement the pores in the iron ore skeleton.

6. The magnetic anchoring and grading grouting sealing method based on high-flow-rate, high-velocity sudden water inrush in tunnels according to claim 1, characterized in that: The outlet of the long grouting pipe (10) is located on the water-facing side of the skeleton and is used for secondary grouting. The grouting pressure is greater than the pressure of the sudden water inrush, ensuring that the cement-based grout (8) can effectively cover the surface of the primary sealing body and fill the contact gap between it and the surrounding rock, forming a high-strength, impermeable reinforced sealing interface.

7. The magnetic anchoring and grading grouting sealing method based on high-flow-rate, high-velocity sudden water inrush in tunnels according to claim 1, characterized in that: The sealing body adopts a pre-installed pipe (4) and graded aggregate composite system, which can effectively adapt to the deformation of the surrounding rock and the pulsating water pressure through elastic deformation, thereby adapting to the complex environment and forming a long-term sealing effect.

8. The magnetic anchoring and grading grouting sealing method based on high-flow-rate, high-velocity sudden water inrush in tunnels according to claim 1, characterized in that: The magnet base (2) adopts a composite design of electromagnet and permanent magnet, and can realize stepless adjustment of magnetic field strength and rapid start and stop through an external power controller.

9. A magnetic anchoring and grading grouting sealing method based on high-flow-rate, high-velocity sudden water inrush in tunnels, as described in claim 8, is characterized in that: The magnet base (2) provides a strong magnetic field during the aggregate filling stage to quickly stabilize the skeleton. After grouting is completed, the magnetic field is reduced or turned off to avoid long-term magnetic interference to subsequent tunnel operations and testing equipment.

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