Dynamic water roadway rapid plugging method based on negative pressure monitoring and flow velocity feedback

Abstract

The invention provides a flowing water roadway rapid plugging method based on negative pressure monitoring and flow velocity feedback, and relates to the technical field of mine water inrush treatment, and the method comprises the following steps: S1, obtaining parameters of a to-be-treated roadway, and calculating the length of a water blocking plug according to the parameters; s2, two roadway penetrating holes are constructed in the roadway to be processed, a negative pressure environment is established through the first roadway penetrating hole, and an average flow velocity calculation model is established after the negative pressure is stable; s3, solving the average flow velocity calculation model, and determining an aggregate pouring regulation and control method of the initial water blocking section according to a solving result; s4, sand and gravel materials and fiber materials are poured through the other hole, and top sealing and water blocking plug forming are sequentially achieved while the length of the water blocking plug is increased; by means of the steps, the problems that in the prior art, blindness exists in the pouring process, the particle size selection basis is fuzzy, blocking stage judgment is lagged, roof contact is difficult, and roof sealing is not tight can be solved.

Description

Technical Field

[0001] This invention relates to the field of mine water inrush control technology, and more specifically to a ground control system and method for cleaning photovoltaic panels based on unmanned aerial vehicles (UAVs). Background Technology

[0002] When encountering a sudden water inrush due to high water pressure and high flow velocity during the construction of mine or other underground engineering tunnels, the tunnel, as a water passageway, makes it crucial to quickly construct a water-blocking plug. Currently, the mainstream method is to inject aggregates (gravel, sand, etc.) into the tunnel through surface boreholes to form a filter body, and then grout it to form a water-blocking plug. However, the method of aggregate injection mainly relies on the experience of technicians and lacks scientific quantitative basis.

[0003] In existing technologies, such as the water-blocking methods for large-scale water flow in underground roadways proposed in documents CN104047620A and CN117662198A, the aggregate particle size and selection basis for each stage of water blocking are not determined. Similarly, the method of injecting concrete into water-flowing roadways proposed in document CN118564288A lacks sufficient setting time for concrete in high-pressure, high-velocity water-flowing roadways, resulting in immediate dilution of the injected concrete, separation of cement and aggregate, material waste, and difficulty in forming an effective water-blocking plug. Therefore, existing technologies have the following inherent defects: (1) The grouting process is blind: the water flow status in the tunnel is unknown, and the aggregate grouting relies on engineering experience to "trial" and cannot be dynamically adjusted according to the real-time water situation, resulting in a large amount of material waste and low sealing efficiency.

[0004] (2) The basis for particle size selection is vague: the selection of aggregate particle size is mostly based on fixed gradation or qualitative experience. Under high-speed water flow conditions, if the particle size is too small, it will be washed away. If the particle size is too large, it will be difficult to form a water-blocking plug with effective length and good water-proof performance. There is a lack of scientific quantitative basis.

[0005] (3) Delay in judging the sealing stage: The judgment of key nodes such as the formation of the water-blocking plug, the top connection status, and the timing of grouting depends on the aggregate grouting intensity and particle size changes or later drilling verification. The feedback is delayed and cannot achieve precise process control.

[0006] (4) Difficulty in connecting the top and poor sealing: In the later stage of aggregate grouting, the water flow is concentrated in the narrow space at the top of the roadway, and the flow velocity increases sharply. Conventional graded aggregates are easily washed away, making it difficult to achieve effective "connection". Even if the aggregates are barely connected to the top, the top structure is often loose and prone to repeated "dam failure" under high water pressure, leading to sealing failure.

[0007] Therefore, how to provide a rapid sealing method for flowing water tunnels that can solve the above problems is a problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0008] In view of this, the present invention provides a rapid sealing method for dynamic water tunnels based on negative pressure monitoring and flow velocity feedback, which solves the problems of blind injection process, ambiguous particle size selection criteria, delayed judgment of sealing stage, difficulty in roof connection and incomplete sealing in the prior art.

[0009] To achieve the above objectives, the present invention adopts the following technical solution: A rapid sealing method for flowing water tunnels based on negative pressure monitoring and flow velocity feedback includes the following steps: S1: Obtain the parameters of the roadway to be treated, and calculate the length of the water-blocking plug based on the parameters; S2: Construct two through holes in the roadway to be treated, use the first through hole to establish a negative pressure environment, and establish an average flow velocity calculation model after the negative pressure stabilizes. S3: Solve the average flow velocity calculation model and determine the aggregate injection control method for the initial water-blocking section based on the solution results; S4: By injecting sand, gravel and fiber material through another hole, the length of the water-blocking plug is increased while the top is sealed and the water-blocking plug is formed in sequence.

[0010] Preferably, S1 specifically includes: The specific expression for calculating the length of the water-blocking plug is: L0≥K0·P0·A / (f0·S·C) In the formula, L0 represents the minimum length required for the water-blocking plug, and P0 represents the dynamic water pressure acting on the cross-section of the water-blocking plug. This indicates the cross-sectional area of ​​the tunnel through which water flows. 0 indicates the coefficient of friction between the water-blocking plug and the surrounding rock of the tunnel. This indicates the perimeter of the contact area between the water-blocking plug and the surrounding rock of the tunnel. This indicates the average compressive strength of the water-blocking plug material. 0 represents the safety factor. This indicates the density of water. Represents gravitational acceleration. Indicates the static head height of the aquifer. This indicates the velocity of the moving water within the tunnel.

[0011] Preferably, S2 specifically includes: S21: Drill two through-holes from the ground to the roadway to be treated, wherein borehole one is located downstream and borehole two is located upstream, and the distance between the two holes is the length of the water-blocking plug obtained in S1. S22: Establish a negative pressure environment using borehole one. After the negative pressure stabilizes, establish an average flow velocity calculation model. The specific expression is as follows:

[0012] In the formula, 0 represents the velocity of the flowing water in the roadway at the point where the borehole penetrates the roadway. This represents the negative pressure on the ground, and k represents a correction factor related to borehole diameter, shape, curvature, etc.

[0013] Preferably, S3 specifically includes: S31: Solve the average flow velocity calculation model and determine the corresponding real-time dynamic water flow velocity based on the solution results; S32: Based on the real-time dynamic water flow velocity, establish a quantitative relationship model for critical aggregate particle size, the specific expression of which is: >D>F×( V 0 2 ) ρ / ( ρ s - ρ ) / g In the formula, D represents the minimum aggregate particle size required to avoid being washed away at a flow rate of V0, and ρ s F represents the density of the aggregate, K represents the settling coefficient, and L represents the settling coefficient. g Indicates the distance of aggregate transport; S33: Determine the aggregate grading and grouting adaptation conditions according to the quantitative relationship model of critical aggregate particle size, and complete the aggregate grading and grouting in borehole one according to the adaptation conditions to form a large-particle-size aggregate water-blocking wall.

[0014] Preferably, S33 specifically includes: (1) In the bottom laying stage, fine aggregate is used to build up a base layer with low porosity on the bottom plate of the roadway to be treated; (2) During the wall construction stage, pour in 1-2 stones and 2-4 stones, and pile the aggregate high; (3) During the top-mounting stage, 1-3 stones are poured to form a large-diameter aggregate water-blocking wall.

[0015] Preferably, S4 specifically includes: S41: Inject sand and fiber materials into borehole 2 to achieve capping; S42: Inject a two-component mortar, consisting of a mixture of cement, water glass, and fine sand, into borehole 2 to seal the gaps between the aggregates. The aggregates and cement slurry then solidify to form a water-blocking plug.

[0016] As can be seen from the above technical solution, compared with the prior art, the present invention discloses a method for rapid sealing of flowing water tunnels based on negative pressure monitoring and flow velocity feedback, which has the following beneficial effects: (1) Avoiding the blindness of the grouting process: The relationship between the negative pressure of the ground borehole and the dynamic water flow velocity in the roadway was established, which can determine the water flow status in the roadway in real time, and provide a basis for the determination of the sealing stage and the selection of aggregate particle size.

[0017] (2) The selection criteria for aggregate particle size were established: Based on the dynamic water flow velocity and aggregate transport distance, the minimum particle size for aggregate initiation and the maximum particle size for sedimentation to the set transport distance were established, and the appropriate aggregate particle size for the bottom laying, wall building and top connection stages were quantitatively determined.

[0018] (3) Implement the judgment and sealing stage: Through the relationship model between ground negative pressure and roadway dynamic water velocity, implement the judgment and sealing stage to achieve precise control of the aggregate injection process.

[0019] (4) Using aggregate and fiber mixed materials to achieve rapid roof sealing: The “cotton-like” or “net-like” structure formed by the intertwining and hooking of fiber materials effectively retains aggregate and reduces aggregate loss. This solves the problem that the narrow space at the top of the roadway during the roof sealing stage, the flow velocity increases sharply, and conventional graded aggregate is easily washed away, thus achieving rapid stage sealing. Attached Figure Description

[0020] 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 embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0021] Figure 1 The overall flowchart of a rapid sealing method for flowing water tunnels based on negative pressure monitoring and flow velocity feedback provided by the present invention; Figure 2 A cross-sectional view of the tunnel sealing borehole layout provided in an embodiment of the present invention; Figure 3 This is a structural diagram of an orifice device for injecting aggregate and monitoring negative pressure, provided in an embodiment of the present invention. Figure 4 This is a schematic diagram of the aggregate accumulation pattern during the bottom laying stage provided in an embodiment of the present invention; Figure 5 This is a schematic diagram of the aggregate accumulation pattern during the wall construction stage provided in an embodiment of the present invention; Figure 6 This is a schematic diagram of the aggregate accumulation pattern during the top-joining stage provided in an embodiment of the present invention; Figure 7 This is a schematic diagram of the aggregate accumulation morphology during the growth water-blocking stage provided in an embodiment of the present invention; Figure 8 This is a schematic diagram of the aggregate morphology during the capping stage provided in an embodiment of the present invention; Figure 9 This is a schematic diagram of the morphology of the water-blocking plug formed by grouting consolidation according to an embodiment of the present invention; Among them Figures 2-9 middle: 1-Tunnel, 2-Water inrush point, 3-First borehole, 4-Second borehole, 5-Casing, 6-Orifice fitting, 7-Negative pressure gauge, 8-Injection port, 9-Flange, 10-Conveying pipe, 11-Aggregate stockpile for the foundation stage, 12-Aggregate stockpile for the wall construction stage, 13-Aggregate stockpile for the roof connection stage, 14-Aggregate stockpile for the roof sealing stage. Detailed Implementation

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

[0023] See Figure 1 As shown in the figure, this invention discloses a rapid sealing method for flowing water tunnels based on negative pressure monitoring and flow velocity feedback, comprising the following steps: S1: Obtain the parameters of the roadway to be treated, and calculate the length of the water-blocking plug based on the parameters; S2: Construct two through holes in the roadway to be treated, use the first through hole to establish a negative pressure environment, and establish an average flow velocity calculation model after the negative pressure stabilizes. S3: Solve the average flow velocity calculation model and determine the aggregate injection control method for the initial water-blocking section based on the solution results; S4: By injecting sand, gravel and fiber material through another hole, the length of the water-blocking plug is increased while the top is sealed and the water-blocking plug is formed in sequence.

[0024] In one specific embodiment, S1 specifically includes: The specific expression for calculating the length of the water-blocking plug is: L0≥K0·P0·A / (f0·S·C) P 0 =P 静 +P 动 = ( ρgh+ρ 2 / 2 )×10 -6

[0025] In the formula, L0 represents the minimum length (m) required for the water-blocking plug, and P0 represents the dynamic water pressure (MPa) acting on the cross-section of the water-blocking plug. Indicates the cross-sectional area of ​​the water passageway (m²) 2 ); 0 represents the friction coefficient between the water-blocking plug and the surrounding rock of the tunnel. It is dimensionless and is a key parameter that requires empirical judgment. It is generally taken as 0.4 to 0.6 between aggregate and rock wall. If the surrounding rock is broken or muddy, a lower value should be taken. S represents the contact perimeter (m) between the water-blocking plug and the surrounding rock of the tunnel. This indicates the average compressive strength of the water-blocking plug material, in MPa. For ungrouted aggregate, the compressive strength is taken as 0.5~1.0 MPa. 0 represents the safety factor, which is dimensionless. Considering dynamic water, it is usually taken as 2.0~5.0, and a higher value is taken under high flow velocity and high water pressure conditions. The density of water is usually expressed as 1000 kg / m³. 3 g represents the acceleration due to gravity, which is usually taken as 9.8 m / s². 2 h represents the static head height of the aquifer (m). This indicates the velocity of the moving water within the tunnel (m / s).

[0026] In one specific embodiment, S2 specifically includes: S21: Drill two through-holes from the ground to the roadway to be treated. Hole 1 is located downstream and hole 2 is located upstream. The distance between the two holes is the length L0 of the water-blocking plug obtained in S1. The water-blocking section is sealed by injecting mixed-size sand and gravel aggregates, as well as fibrous materials such as woven bags and hemp ropes. Then, cement grout is injected to consolidate the aggregates and form a complete water-blocking plug. S22: Establish a negative pressure environment using borehole one. This is achieved by injecting water into borehole one: water is injected into the first borehole through an orifice, and the negative pressure value is monitored using a negative pressure gauge installed on top of the orifice. Once the negative pressure stabilizes, an average flow velocity calculation model is established based on Bernoulli's equation and the principles of pipe fluid dynamics. The specific expression is as follows:

[0027] In the formula, 0 represents the flow velocity of the dynamic water in the roadway at the borehole penetration point (m / s). The value represents the ground negative pressure (Pa, less than 0), and k represents the correction coefficient related to borehole diameter, shape, curvature, etc., which is obtained through field experiments.

[0028] In one specific embodiment, S3 specifically includes: S31: Solve the average flow velocity calculation model and determine the corresponding real-time dynamic water flow velocity based on the solution results; S32: Based on the real-time dynamic water flow velocity, establish a quantitative relationship model for critical aggregate particle size, the specific expression of which is: >D>F×( V 0 2 ) ρ / ( ρ s - ρ ) / g In the formula, D represents the minimum aggregate particle size (m) required to avoid being washed away at a flow velocity of V0, and ρ s The density of the aggregate is expressed in kg / m³; F represents the initiation coefficient, an empirical coefficient related to particle concentration and particle size, which is typically between 0.8 and 1.2 for uniform sand and between 1.3 and 1.8 for gravel under initiation conditions; K represents the settling coefficient, an empirical coefficient related to particle concentration and particle size; L... g This represents the aggregate transport distance (m), slightly greater than L0; S33: Determine the aggregate grading and grouting adaptation conditions according to the quantitative relationship model of critical aggregate particle size, and complete the aggregate grading and grouting in borehole one according to the adaptation conditions to form a large-particle-size aggregate water-blocking wall.

[0029] In one specific embodiment, S33 specifically includes: Commonly used aggregates for tunnel closure include coarse sand (0.5-2mm), 5-1 gravel (5-10mm), 1-2 gravel (10-20mm), 1-3 gravel (16-31.5mm), 2-4 gravel (10-15mm), and 4-6 gravel (15-20mm).

[0030] (1) The bottom layer stage (V0≤1.5v) uses fine aggregate to form a base layer with low porosity by accumulating it on the bottom plate of the roadway to be treated; (2) Wall building stage (1.5v<V0≤3v), pour in 1-2 stones, 2-4 stones, and pile up the aggregate; (3) Top connection stage (3v < V0), 1-3 stones are poured to form a large-diameter aggregate water barrier wall.

[0031] In one specific embodiment, S4 specifically includes: S41: Sand and gravel and fiber materials are injected into borehole two to achieve sealing. However, due to the high velocity of the water flow at the top, the injected sand and gravel will be quickly washed away, preventing sealing. Therefore, fiber materials such as hemp rope and woven bags are cut into 5-15cm long sections and mixed with graded aggregate consisting of coarse sand to 13-gravel stones through borehole two and injected into the tunnel. The fiber materials disperse in the water, intertwine and hook onto the aggregate accumulation and the anchor cable heads and anchor bolt heads at the top of the tunnel, forming a "cotton-like" or "net-like" barrier structure. After the graded aggregate consisting of coarse sand to 13-gravel stones is injected, it can effectively remain at the top of the tunnel, quickly blocking any remaining gaps and forming a dense, erosion-resistant sealing layer. S42: Inject a two-component mortar, consisting of cement, water glass, and fine sand, into borehole 2 to seal the gaps between the aggregates. The aggregate and cement slurry solidify to form a water-blocking plug. At this point, water still passes through the gaps between the aggregates. Inject a two-component mortar, consisting of cement, water glass, and fine sand, into borehole 2 to seal the gaps between the aggregates. The aggregate and cement slurry solidify to form a water-blocking plug.

[0032] After the water level in borehole 2 rises to the original groundwater level by repeatedly injecting double-liquid mortar, cement grout with a specific gravity of 1.4 to 1.6 is injected to reinforce the water-blocking plug using a static pressure downward grouting method. The grouting pressure should reach 2 to 3 times the static water pressure of the aquifer.

[0033] Specifically applying the methods provided in the embodiments of the present invention

[0034] Taking a coal mine roadway in Guizhou as an example, a water inrush occurred during tunneling due to the exposure of a water-conducting fault zone, with the maximum inrush volume reaching approximately 1700 m³. 3 / h, stable inrush volume approximately 780m³ 3 / h. The tunnel is 382m deep and was excavated downhill at a 9° slope. Due to insufficient drainage system, the tunnel was flooded. This invention was subsequently used to quickly intercept the flowing water in the tunnel, including the following steps: Step 1: Calculate and determine the length of the water-blocking plug In this example, the aquifer's static head height h is approximately 357m, the static pressure Pstatic is approximately 3.5MPa, the tunnel width is 4.0m, the height is 2.8m, and the cross-sectional area A is 11.2m². 2 Flow velocity The velocity is 0.02 m / s, the contact perimeter S between the water-blocking plug and the surrounding rock is 13.6 m, the friction coefficient f0 between the aggregate and the rock wall is 0.5, the safety factor K0 is 4.0, and the density of water is... Take 1000 kg / m 3 The gravitational acceleration g is taken as 9.8 m / s². 2 The average compressive strength of the ungrouted water-blocking plug material is taken as 0.3 MPa. Substitute the above parameters into the following formula for calculation: P0=P 静 +P 动 =(ρgh+ρ 2 / 2)×10 -6 ≈3.50MPa (1) L0≥K0·P0·A / (f0·S·C)=4×3.50×11.2 / (0.5×13.6×0.7)≈33.00m (2)

[0035] Step 2: Drilling holes in the tunnel for construction

[0036] like Figure 2As shown, two through-holes are constructed from the ground to the tunnel. The first borehole (i.e., borehole one) is located downstream, and the second borehole (i.e., borehole two) is located upstream. The distance between the boreholes is the length of the water-blocking plug L0 = 33m. The first through-hole is 63m away from the water inrush point, and the second through-hole is 30m away from the water inrush point.

[0037] The casing is installed from the ground to a position 20m above the top of the tunnel, and cemented to isolate the upper aquifer.

[0038] Step 3: Inject water into the first borehole to establish a negative pressure environment. Based on the surface negative pressure and the initial dynamic water velocity in the tunnel, construct the correlation function between negative pressure and dynamic water velocity.

[0039] 1) such as Figure 3 As shown, the orifice fitting is installed at the borehole casing opening, and a flow rate of Q = 100 m³ / h ≈ 0.028 m³ is continuously injected into the first borehole through the orifice fitting. 3 / s of water, creating a negative pressure environment; 2) Using a negative pressure gauge installed on top of the orifice, the stable negative pressure value P is monitored to be -0.01 MPa. Based on Bernoulli's equation and the principles of pipe fluid mechanics, a function of the average flow velocity (V0) in the roadway is established and solved. The specific expression is as follows: (3) In the formula, 0 represents the flow velocity of the dynamic water in the roadway at the borehole penetration point (m / s). This represents the ground negative pressure (Pa, a value less than 0), and k represents a correction coefficient related to borehole diameter, shape, curvature, etc., which is calibrated through field experiments.

[0040] Under the initial conditions before the tunnel was blocked 0= 0.02 m / s, k = 5 × 10⁴ is calculated.

[0041] Step 4: Based on the real-time dynamic water flow velocity in the roadway, quantitatively match the aggregate particle size during grouting to determine the aggregate grouting control method for constructing the initial water-blocking section.

[0042] Through step three, the initial dynamic water flow velocity in the tunnel is determined. 0.02 m / s, based on the theory of particle initiation velocity in water flow, utilizing the critical aggregate particle size (D) and real-time flow velocity ( The quantitative relationship model of 0) is used to calculate the particle size of the cast-in-place aggregate, as follows: >D>F (V0) 2 )ρ / (ρ s -ρ) / g (4) In this embodiment: the density ρ of the aggregate sTake 2650 kg / m³, start-up coefficient F = 1.3, settlement coefficient K = 0.5, and aggregate transport distance L = 1.3. g Take 35m.

[0043] 2) Aggregate grading and injection strategy: Commonly used aggregates for roadway interception include coarse sand (0.5-2mm), 5-1 gravel (5-10mm), 1-2 gravel (10-20mm), 1-3 gravel (16-31.5mm), 2-4 gravel (10-15mm), and 4-6 gravel (15-20mm). The matching conditions for flow velocity and aggregate particle size at each stage are determined by formula (4) as follows: (1) Laying the foundation stage (V0≤0.03m / s): such as Figure 4 As shown, the water passage cross-section of the tunnel is relatively large and the flow velocity is low. Fine aggregates, mainly coarse sand (0.5-2.0mm in diameter) and 5-1 gravel (5-10mm in diameter), are piled up on the tunnel floor to form a base layer with low porosity, which reduces the water passage cross-sectional area, increases the dynamic water flow velocity in the tunnel, and creates conditions for the injection of large-diameter aggregates.

[0044] (2) Wall-building stage (0.03m / s < V0 ≤ 0.06m / s): such as Figure 5 As shown, as the cross-sectional area of ​​the water flow decreases, the velocity of the flowing water increases, the D value calculated by the model increases, the aggregate gradation switches from fine to coarse, and 1-2 stones and 2-4 stones are poured, and the aggregate is piled up.

[0045] (3) Roofing stage (0.06m / s < V0): such as Figure 6 As shown, the cross-sectional area of ​​the water passage is further reduced, the velocity of the flowing water is further increased, and 1-3 stones are injected to form a water-blocking wall of large-particle aggregate with high permeability, so as to realize the energy dissipation of the water passage and avoid the crushing of the aggregate water-blocking wall under the action of hydrostatic pressure and dynamic water impact. Specific adaptation conditions are shown in Table 1.

[0046] Table 1 Adaptation Conditions

[0047] After the aggregate water-blocking wall is formed, it enters the growth water-blocking plug and capping stage.

[0048] Step 5: Pour sand and gravel into the second borehole to increase the length of the water-blocking plug.

[0049] After step four, an aggregate water barrier wall for water dissipation has been established near the downstream first borehole. At this point, it is necessary to increase the length of the aggregate water barrier wall.

[0050] 1) Inject water into the second borehole and use negative pressure to calculate the dynamic water flow velocity in the bottom tunnel.

[0051] like Figure 7As shown, in this embodiment of the invention, water was injected into the second borehole, and the initial negative pressure was measured to be -0.02 MPa. A mixture of coarse sand, 1-2 and 2-4 gravel was injected in a ratio of 1:1:1. The negative pressure was gradually increased to -0.09 MPa, during which the proportion of coarse sand was gradually reduced. Finally, 1-3 gravel was injected at the top to form a water-blocking plug with an effective length greater than 33m.

[0052] Step Six: Inject sand and fiber materials into the second borehole to seal it.

[0053] Step five has created a water-blocking wall of aggregate of a predetermined length within the tunnel. However, due to the high velocity of the water flow at the top, the injected sand and gravel will be quickly washed away, preventing the tunnel from being sealed. For example... Figure 8 As shown, fibrous materials such as hemp rope and woven bags are cut into 10-15cm long segments and mixed with coarse sand, 1-2 and 1-3 gravel in a 1:1:1 ratio through the second drill hole and injected into the tunnel. The fibrous materials disperse in the water, intertwine and hook onto the aggregate accumulation and the anchor cable heads and anchor rod heads at the top of the tunnel, forming a "cotton-like" or "net-like" barrier structure. After the injection of graded materials ranging from coarse sand to 13 gravel, it can effectively remain on the top of the tunnel, quickly blocking any remaining gaps and forming a dense, erosion-resistant sealing layer.

[0054] After grouting was completed, the water head height in the borehole increased from 261m before grouting to 341m, and the water level rose by 80m, indicating that the aggregate water-blocking wall had been capped. The next step is to gradually reinforce it.

[0055] Step 7: Grouting to form a water-blocking plug

[0056] Step six is ​​used to achieve the top connection of the aggregate water-blocking wall. At this time, the gaps between the aggregates are still filled with water. The gaps between the aggregates are sealed by injecting a two-liquid mortar formed by the mixture of cement, water glass and fine sand through the second borehole. The aggregate-cement grout solidifies to form a water-blocking plug.

[0057] like Figure 9 As shown, after repeatedly injecting double-liquid mortar and observing the water level in the second borehole rise to the original groundwater level, a cement grout with a specific gravity of 1.4~1.6 is injected to reinforce the water-blocking plug using a static pressure downward grouting method. The grouting pressure should reach twice the static water pressure of the aquifer, with a final pressure of 7MPa.

[0058] In summary, by utilizing the established relationship between the negative pressure of ground boreholes and the velocity of flowing water in the tunnel provided by the embodiments of the present invention, the velocity of flowing water in the tunnel can be determined by real-time monitoring of the negative pressure, the sealing process can be accurately grasped, and the three stages of bottom laying, wall construction, and roof connection can be clearly divided.

[0059] In this embodiment, by utilizing the established relationship between aggregate and flowing water velocity, the appropriate aggregate particle size is precisely and quantitatively adjusted for the three stages of bottom laying, wall construction, and top connection. After water blocking is completed, the amount of aggregate loss downstream of the water-blocking plug is minimal, achieving precise control of the aggregate grouting process. This greatly avoids aggregate waste and improves the scientific nature of aggregate grouting.

[0060] In this embodiment of the invention, a mixture of aggregate and fiber is used to achieve rapid capping. The "cotton-like" or "net-like" structure formed by the intertwining and hooking of fiber materials is cleverly utilized to effectively retain aggregate and reduce aggregate loss. This solves the problem that the narrow space at the top of the roadway during the capping stage, where the flow velocity increases sharply, makes conventional graded aggregates easily washed away, thus achieving rapid stage capping.

[0061] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the apparatus disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the description is relatively simple; relevant parts can be referred to the method section.

[0062] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for rapid sealing of a water tunnel based on negative pressure monitoring and flow rate feedback, characterized in that, The method comprises the following steps: S1: obtaining parameters of a roadway to be treated, and calculating a water-blocking plug length according to the parameters; S2: constructing two roadway-through holes in the roadway to be treated, establishing a negative pressure environment by using a first roadway-through hole, and establishing an average flow velocity calculation model after the negative pressure is stabilized; S3: solving the average flow velocity calculation model, and determining an aggregate pouring control method of an initial water-blocking section according to a solving result; S4: pouring sand and gravel and fiber materials through another hole, increasing the length of the water-blocking plug, and sequentially achieving capping and forming the water-blocking plug.

2. The method according to claim 1, wherein, The S1 specifically comprises: A specific expression for calculating the water-blocking plug length is: L0≥K0·P0·A / (f0·S·C) wherein L0 represents the minimum length required for the water-blocking plug, P0 represents the hydrodynamic pressure acting on the cross section of the water-blocking plug, represents the cross-sectional area of the roadway passing water, 0 represents the friction coefficient of the water-blocking plug and the surrounding rock of the roadway, represents the contact perimeter of the water-blocking plug and the surrounding rock of the roadway, represents the average compressive strength of the water-blocking plug material, 0 represents the safety factor, represents the density of water, represents the acceleration of gravity, represents the static water head height of the aquifer, represents the flow velocity of the water in the roadway.

3. The method according to claim 2, wherein, The S2 specifically comprises: S21: constructing two roadway-through holes from the ground to the roadway to be treated, wherein a first hole is located downstream, a second hole is located upstream, and a distance between the two holes is the water-blocking plug length obtained in the S1; S22: establishing a negative pressure environment by using the first hole, and establishing an average flow velocity calculation model after the negative pressure is stabilized, and a specific expression is: In the formula, 0 represents the water flow velocity of the roadway at the drilling penetration point, represents the ground negative pressure, and k represents a correction coefficient related to the drilling diameter, shape, and bending degree.

4. The method according to claim 3, wherein, The S3 specifically comprises: S31: solving the average flow velocity calculation model, and determining a real-time dynamic water flow velocity according to a solving result; S32: establishing a critical aggregate particle size quantitative relationship model according to the real-time dynamic water flow velocity, and a specific expression is: >D>F x ( V 0 2 ) ρ / ( ρ s - ρ ) / g In the formula, D represents the minimum aggregate particle size required not to be washed away at a V0 flow rate, p s represents the density of the aggregate, F represents a start-up coefficient, K represents a settlement coefficient, L g represents the aggregate migration distance; S33: determining aggregate grading pouring adaptation conditions according to the critical aggregate particle size quantitative relationship model, and completing aggregate grading pouring into the first hole according to the adaptation conditions to form a large-particle-size aggregate water-blocking wall.

5. The method according to claim 4, wherein, The S33 specifically comprises: (1) a bottom paving stage, in which fine aggregate is used to accumulate a foundation layer with small porosity on a floor of the roadway to be treated; (2) a wall building stage, in which 1-2 pebbles and 2-4 pebbles are poured to form an aggregate pile; (3) a top capping stage, in which 1-3 pebbles are poured to form a large-particle-size aggregate water-blocking wall.

6. The method according to claim 4, wherein, The S4 specifically comprises: S41: pouring sand and gravel and fiber materials into the second hole to achieve capping; S42: pouring a double-liquid mortar formed by mixing cement-sodium silicate-fine sand into the second hole to seal gaps between aggregates, and solidifying the aggregates-cement mortar to form a water-blocking plug.

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