Rapid plugging and water intercepting method for water guide roadway

Abstract

The invention relates to the technical field of water disaster prevention and control of mining, and provides a rapid plugging and water intercepting method for a water guide roadway, which comprises the following steps: S1, obtaining a three-dimensional space form, surrounding rock integrity and a water accumulation state of the water guide roadway through a plurality of detection drill holes in combination with a drill hole imaging technology; s2, based on an exploration result, selecting a roadway section which is complete in surrounding rock and far away from a mining boundary as a cutoff wall construction position, and designing a grouting hole arrangement scheme for batch construction; s3, aggregate feeding is conducted in sequence to form a low-position retaining wall, low-pressure filling grouting is conducted to form a stone body, and high-pressure joint grouting is conducted to compact a joint; s4, grouting stone body coring, water pressing test and imaging detection are conducted through the inspection drill hole, and the compactness of the cutoff wall is evaluated; and S5, performing supplementary injection reinforcement on the weak area according to a detection result. The water diversion roadway can be quickly sealed and intercepted, and the water disaster threat of the large-flow water diversion roadway is effectively relieved.

Description

Technical Field

[0001] This invention relates to the field of water hazard prevention and control technology in mining, and in particular to a method for rapid sealing and interception of water in diversion tunnels. Background Technology

[0002] Underground goaf water is often characterized by large water volume, high head pressure, and abundant recharge water. During mine production, when there are well-connected water channels between the mining-affected area and the goaf water-filled area, the goaf water can seep into the rock strata within the mining-affected area, worsening the surrounding rock structure, increasing the cost of goaf water treatment, and even exacerbating the risk of mine water-related accidents. In open-pit coal mine operations, this can induce geological disasters such as landslides and collapses. Therefore, mine operations affected by water flowing through goaf water diversion channels are a serious hazard that threatens safe production. Currently, the most commonly used technical measures for treating strong water diversion channels in underground goafs during mine production operations are two main methods: goaf water exploration and drainage technology and goaf water interception and isolation technology. The exploration and drainage technology for treating old working water is a relatively conventional method for managing old working water in mine goaf areas. However, achieving good treatment results with this method is often limited by the characteristics of the old working water itself and the capacity of the mine's drainage system. When the old working water in the goaf is static and the water head pressure is not high, using exploration and drainage boreholes to treat the accumulated water in the goaf and reduce the water head pressure has a certain degree of safety and efficiency. However, when faced with large water volumes, abundant dynamic recharge, and good connections between the mining-affected area and the old working water in the goaf, the effectiveness of conventional drainage boreholes in eliminating the threat of old working water hazards is limited. Often, the results are unsatisfactory, and there are many bottlenecks. First, when facing large volumes of water and abundant replenishment of old goaf water, the drainage capacity of the drainage boreholes is limited, making it difficult to reduce the water head pressure in a short period of time. Second, the drainage system equipped in the mine may not be able to effectively meet the drainage needs of large volumes of old goaf water. When faced with situations where there is a large amount of accumulated water, abundant replenishment of water source, and a good hydraulic connection channel (water passageway) with the mining-affected area, drainage through exploration and drainage boreholes will greatly reduce the efficiency of old goaf water treatment in the goaf area, while increasing the engineering investment and time cost of treatment. It is difficult to control both the economic benefits and the ease of implementation.

[0003] In the past, the water interception and isolation technology used in mining operations to deal with water hazards in old workings mainly fell into two categories. One was grouting curtain sealing, which mainly involved high-pressure grouting at the boundary of the workings or key seepage channels using cement-water glass composite grout or polymer materials to form a continuous water-blocking curtain, cutting off the connection between old workings water and surrounding aquifers. However, this method was mainly suitable for water-conducting fractures in rock strata with small water passages and not suitable for sealing roadways with large flow rates. The other was constructing physical isolation barriers. The method mainly involves constructing a rigid water-blocking structure by combining a concrete isolation wall with a water gate. However, the treatment time is quite strict, requiring that there be no water flow at the treatment site. This method is not suitable for situations where there is a large water flow and abundant water supply in the hidden space of the goaf. Moreover, the construction plan lacks the exploration and judgment of the surrounding rock conditions at the location of the isolation wall, and the scientific rationality of the construction site selection is poor. When the construction wall encounters broken surrounding rock or a roadway with a collapsed roof, the sealing and isolation will fail. Therefore, the traditional method has a great deal of blindness.

[0004] Therefore, existing technologies for treating old goaf water in mining operations do not offer a scientifically reliable method for quickly sealing water diversion channels when there are well-connected water diversion channels between the mining-affected area and the goaf water accumulation area. Summary of the Invention

[0005] This invention provides a method for rapid sealing and water interception in diversion tunnels, which addresses the shortcomings of existing technologies in situations where there is a large amount of accumulated water, abundant dynamic replenishment, and a good connection between the mining impact area and the old goaf water, making it difficult to effectively and quickly manage the old goaf water. This method enables rapid sealing and water interception in diversion tunnels, effectively eliminating the water hazard threat of high-flow diversion tunnels.

[0006] This invention provides a method for rapid sealing and water interception in a water diversion tunnel, comprising the following steps: S1. By using multiple exploratory boreholes and combining borehole imaging technology, the three-dimensional spatial morphology, surrounding rock integrity, and water accumulation status of the water diversion tunnel are obtained. S2. Based on the exploration results, select a roadway section with intact surrounding rock and far from the mining boundary as the location for the cutoff wall construction, and design a grouting hole layout scheme for phased construction. S3. The aggregate is fed in sequence to form a low-level retaining wall, low-pressure filling and grouting are used to form a stone body, and high-pressure joint grouting is used to compact the joint. S4. By inspecting the boreholes, core samples of the grouting stone body are taken, water pressure tests are conducted, and imaging detection is performed to assess the compactness of the cutoff wall. S5. Based on the test results, reinforce the weak areas.

[0007] According to the present invention, a method for rapid sealing and water interception of a water diversion tunnel is provided, wherein the plurality of the detection boreholes include at least a first type of borehole that also serves as a grouting hole and a second type of borehole that also serves as an aggregate feeding hole.

[0008] According to the method for rapid sealing and water interception of a water diversion tunnel provided by the present invention, step S2, the grouting hole layout scheme for phased construction specifically includes: The position and spacing of the grouting holes in the next stage are dynamically adjusted based on the grouting diffusion situation in the previous stage. The spacing ranges from 5 to 15 meters, and the spacing increases with the slope.

[0009] According to the present invention, a method for rapid sealing and interception of water in a water diversion tunnel is provided. In step S3, the aggregate is gravel or crushed stone, and the aggregate is fed to form a physical skeleton to intercept the diffusion of slurry.

[0010] According to the present invention, a method for rapid sealing and water interception of a water diversion tunnel is provided. In step S3, the low-pressure filling grouting uses cement fly ash slurry with a water-cement ratio of 0.6:1 to 0.8:1.

[0011] According to the present invention, a method for rapid sealing and water interception of a water diversion tunnel is provided. In step S3, the high-pressure joint grouting uses cement fly ash slurry with a water-cement ratio of 0.8:1 to 1:1, and the slurry selectively contains polymer materials or quick-setting agents.

[0012] According to the present invention, a method for rapid sealing and water interception of a water diversion tunnel is provided. In step S4, the inspection step includes constructing at least two inspection boreholes, performing core sampling, water pressure testing and imaging detection respectively, and comprehensively evaluating the density of the contaminated stone and the connection with the roof.

[0013] The method for rapid sealing and water interception of a water diversion tunnel provided by the present invention further includes: setting up water level monitoring boreholes in the tunnel area outside the water interception wall to monitor changes in water level in real time and evaluate the water interception effect.

[0014] According to the present invention, a method for rapid sealing and water interception of a water diversion tunnel is provided, wherein the water interception wall is constructed at a distance of not less than 100m from the mining boundary and avoids the tunnel collapse zone and the stress concentration zone.

[0015] According to the present invention, a method for rapid sealing and water interception of a water diversion tunnel is provided. In step S5, a low-viscosity, high-permeability polymer material may be selectively added to the grout used for reinforcement.

[0016] The present invention provides a rapid water-blocking and interception method for water-diversion tunnels. Based on the distribution characteristics of water-diversion tunnels and their relationship with the mine working space, the method involves investigating and analyzing the surrounding rock and water accumulation in the underground goaf water-diversion tunnel space, rationally selecting the location of the cutoff wall, and using grouting for interception. This achieves rapid water blocking and interception of the water-diversion tunnel, providing a safe and efficient solution for quickly removing large volumes of water and strongly replenishing old working water in mining operations. It can effectively eliminate the water hazard threat of high-flow-rate water-diversion tunnels. By designing a grouting and water-blocking effect verification step for the cutoff wall, it is beneficial to take corresponding water-blocking and reinforcement measures based on the effect verification results, thereby ensuring the quality of the cutoff wall and improving the reliability of water blocking and interception. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in this 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 some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0018] Figure 1 This is a flowchart illustrating the rapid sealing and water interception method for water diversion tunnels provided by the present invention.

[0019] Figure 2 This is a schematic diagram of the borehole layout provided by the present invention.

[0020] Figure 3 This is a real-scene photograph of borehole imaging in a goaf area provided by the present invention.

[0021] Figure 4 This is a plan view of the grouting treatment and borehole layout provided by the present invention.

[0022] Figure 5 This is a cross-sectional schematic diagram of the grouting treatment and borehole layout provided by the present invention. Detailed Implementation

[0023] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0024] In the description of this invention, it should be understood that the terms "top", "bottom", "inner", "outer", "axial", "radial", "circumferential", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0025] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a communication connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0026] In this invention, unless otherwise expressly specified and limited, the first feature "on" or "below" the second feature may be in direct contact with the first and second features, or indirect contact through an intermediate medium. In the description of this specification, references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0027] refer to Figure 1 This invention provides a method for rapid sealing and water interception in a water diversion tunnel, comprising the following steps: S1. By using multiple exploratory boreholes and combining borehole imaging technology, the three-dimensional spatial morphology, surrounding rock integrity, and water accumulation status of the water diversion tunnel are obtained. S2. Based on the exploration results, select a roadway section with intact surrounding rock and far from the mining boundary as the location for the cutoff wall construction, and design a grouting hole layout scheme for phased construction. S3. The aggregate is fed in sequence to form a low-level retaining wall, low-pressure filling and grouting are used to form a stone body, and high-pressure joint grouting is used to compact the joint. S4. By inspecting the boreholes, core samples of the grouting stone body are taken, water pressure tests are conducted, and imaging detection is performed to assess the compactness of the cutoff wall. S5. Based on the test results, reinforce the weak areas.

[0028] Existing methods for managing old goaf water in mining operations typically involve drilling water exploration holes around the goaf or using curtain grouting to block the recharge channels between the old goaf water and the mining-affected area. These are common methods for managing old goaf water in mining operations. However, these methods are less effective in managing old goaf water with large volumes of water and relatively unobstructed drainage tunnels. This invention provides a rapid sealing and interception method for drainage tunnels in old goaf areas of mines. Based on the distribution characteristics of drainage tunnels and their relationship to the mine's operating space, the invention investigates and analyzes the surrounding rock and water accumulation in the drainage tunnel space of the underground goaf area, rationally selects the location of the cutoff wall, and achieves rapid sealing and interception of the drainage tunnel through grouting. This provides a safe and efficient solution for quickly removing large volumes of water and strongly recharged old goaf water in mining operations, effectively eliminating the water hazard threat of large-flow drainage tunnels. By designing a grouting and water-cutting effect inspection process for the cutoff wall, it is possible to take corresponding supplementary grouting and reinforcement measures based on the inspection results, thereby ensuring the quality of the cutoff wall and improving the reliability of the sealing and water-cutting.

[0029] By using multi-probe drilling and borehole imaging technology in step S1 to accurately explore the three-dimensional spatial morphology, surrounding rock integrity, and water accumulation status of the water diversion tunnel, combined with the scientific site selection of the tunnel section with intact surrounding rock and far from the mining boundary in step S2, it is possible to accurately cope with the complex working conditions of hidden space water diversion tunnels, large flow of water, and abundant water supply. This solves the core problem that traditional technologies are difficult to apply in such scenarios and fills the technical gap in the treatment of blockage of large flow and strong supply water diversion tunnels.

[0030] This invention significantly improves the sealing efficiency of water-diverting tunnels through a combination of step-by-step construction and precise grouting, providing crucial support for quickly eliminating water hazards in mining operations. Step S3, with its process design of aggregate delivery forming a low-level retaining wall, low-pressure grouting forming a concretionary body, and high-pressure grouting to compact the joints, utilizes aggregate delivery to quickly construct the initial water-blocking foundation, low-pressure grouting to rapidly form a continuous concretionary body, and high-pressure grouting to address the joint compaction issue. This three-step synergy achieves rapid blocking, initial solidification, and precise compaction in a progressive sealing process. It boasts advantages in rapid flow interception and high pressure resistance, avoiding the time-consuming issues of traditional physical isolation walls that require strict timeframes and the absence of water flow. It also avoids the drawbacks of long drainage cycles and difficulty in rapidly reducing pressure associated with exploration and release techniques. In scenarios with large water volumes and strong replenishment, it can quickly cut off old workings seepage channels, significantly shortening the treatment cycle and creating conditions for the mine to resume safe operations as soon as possible. This invention does not rely on large-scale pumping equipment, thus avoiding the problems of high investment and high energy consumption costs of large-volume pumping drainage systems in exploration and release technology; through precise exploration and step-by-step construction, it reduces the waste of grout and the losses from repeated construction in traditional grouting technology.

[0031] In some embodiments, step S1 specifically includes: Multiple exploratory boreholes are set up to acquire images of the surrounding rock and water conditions in the tunnel using borehole imaging instruments. Based on existing mining data, the distribution area of ​​the water diversion tunnel is determined, and the surrounding environment is explored to provide a reference for the location of the cutoff wall. Through construction exploratory boreholes and high-definition borehole imaging, the three-dimensional spatial morphology of the water diversion tunnel, the integrity of the surrounding rock, and the distribution of collapsed areas can be obtained, providing a scientific basis for subsequent cutoff wall site selection. The cutoff wall location must avoid collapsed areas in the tunnel; understanding the surrounding rock condition and water accumulation is fundamental to developing a reasonable grouting plan and supporting the efficient implementation of the grouting project. Exploration can identify unfavorable geological areas such as fractured zones and cavities, avoiding the placement of the cutoff wall in easily unstable areas; water accumulation analysis (such as flow velocity and water level) can optimize the grouting material ratio. In optimizing the cutoff wall design, the grouting pressure and diffusion radius can be adjusted according to the density of the surrounding rock to prevent excessive grout diffusion; combined with tunnel height and width data, the volume of the cutoff wall and the grouting volume are accurately calculated, ensuring sufficient preparation for the construction of the cutoff wall. In addition, the initial exploration data can provide a benchmark for subsequent water level monitoring, ensuring the accuracy and reliability of water level monitoring.

[0032] Existing methods for constructing isolation walls to address water diversion tunnels in goaf areas lack systematic exploration and scientific assessment of the site selection area. They rely solely on experience or preliminary surveys to determine the construction location, leading to frequent construction failures due to improper site selection. For example, if a fractured rock zone is mistakenly selected, the surrounding loose rock will be insufficient to provide support after wall pouring or grouting, making the wall prone to cracking and displacement under water pressure. Alternatively, if the site is too close to the mining boundary, the mining impact will continuously disturb the surrounding rock, causing cracks at the interface between the isolation wall and the surrounding rock, resulting in loss of water-blocking function. Furthermore, if the tunnel's spatial morphology and water distribution are not fully understood, the wall may not completely cover the water diversion channel (e.g., hidden branch tunnels may be omitted), or it may be constructed directly in a high-pressure, waterlogged area, making it susceptible to being washed away during construction. This invention, through steps S1 and S2, avoids the risks of wall cracking, leakage, and instability inherent in existing methods from the source of site selection, providing a solid foundation for isolation wall construction. The location of the isolation wall not only determines the success or failure of its construction, but also directly affects the efficiency and quality of subsequent grouting construction: if the existing technology selects the site in the fractured surrounding rock zone, the grout is prone to flow into the loose surrounding rock during subsequent grouting, resulting in a surge in grouting volume and difficulty in forming the stone body, which increases material costs and requires repeated grouting; if the site is close to the mining boundary, the mining disturbance after grouting may destroy the stone body and cause secondary rework.

[0033] like Figure 2 As shown, for example, four core sampling boreholes are drilled on one side of the pre-designated sealed wall to understand the conditions of the coal seam roof and roadway space. Simultaneously, a high-definition borehole imaging instrument is used to acquire high-definition images of the surrounding rock and water conditions in the roadway space (e.g., Figure 3(As shown). Based on multi-source information, a cross-sectional diagram of the tunnel is drawn. Among these, the multiple exploratory boreholes include at least a first-type borehole that also serves as a grouting hole and a second-type borehole that also serves as an aggregate feeding hole. (As shown) Figure 2 In the example, the four exploratory boreholes are labeled TC1, TC2, TC3 and TC4 respectively. TC1 and TC2 can be used as observation holes and grouting holes, while TC3 and TC4 can be used as observation holes and aggregate feeding holes. The spacing between TC1 / TC2 and TC3 / TC4 can be set to 5-15m.

[0034] In some embodiments, for step S2, the cutoff wall should be constructed in roadway sections with good support, straight and intact boundaries, and dense and hard surrounding rock, avoiding concentrated stress zones from surrounding mining activities. Based on the known orientation of the underground water diversion roadway and its position relative to the mine operation area, and considering the connectivity of the underground roadways, the hydrostatic pressure of water accumulated in the underground goaf, and the disturbance of the mine operation to the sidewalls and surrounding rock, the location of the cutoff wall in the water diversion roadway should be no less than 100m from the mining boundary. One cutoff wall is designed to be constructed in each water diversion roadway in the direction of water inflow from the goaf of the underground working face. The actual construction location can be adjusted appropriately based on the roadway space exploration results.

[0035] According to relevant regulations on coal mine water control, when there is large-scale lateral water accumulation in the same coal seam, it must be ensured that mining cracks do not affect the water accumulation area, and the distance between the mining space and the water accumulation boundary should meet the requirements for leaving lateral water-blocking coal pillars. The thickness of the cutoff wall and the length of the grouting section (e.g., ...) must be calculated and determined. Figure 5 The length of the grouting stone body in the wall should be greater than the calculated thickness of the cutoff wall.

[0036] For example, at least six grouting holes (including two exploratory holes) are constructed in the cutoff wall. Construction is carried out in batches, and the location of the grouting holes in the next stage is determined based on the grout diffusion situation of the previous stage. Following the principle of comprehensive control, the holes are laid out at intervals of 5–15 meters, with the spacing increasing as the slope increases. This invention optimizes the hole positions in real time based on the grout diffusion situation, breaking the limitations of traditional one-time fixed hole layout. Through post-grouting testing (such as borehole imaging and water pressure tests), the actual grout diffusion boundary, filling density, and uncovered areas can be accurately grasped. If the grout diffusion in a certain area is insufficient, the next stage can specifically shift the grouting holes towards that blind area, or add supplementary holes around the blind area. If the diffusion range in some areas exceeds expectations, the spacing between adjacent holes can be appropriately adjusted to avoid repeated coverage. This dynamic supplementation mode ensures that the grout comprehensively covers the water diversion tunnel and surrounding seepage channels, completely eliminating the sealing blind areas that are difficult to avoid with traditional fixed hole layout, and significantly improving the sealing integrity. At the same time, it can optimize grout resource allocation, avoid insufficient or excessive grouting, and reduce project costs. For roadways with steep slopes, gravity enhances the guiding effect of grout. Driven by grouting pressure, the grout flows rapidly downhill along the slope, increasing the effective diffusion length of a single grouting hole. Even with increased hole spacing, the diffusion zones of adjacent holes can still achieve effective connection, eliminating the need for dense hole placement to seal the core water-conducting channels. This reduces construction work and avoids grout waste in non-critical areas. Figure 4 As shown, the six grouting holes are labeled TC1, TC2, ZJ1, ZJ2, ZJ3 and ZJ4 respectively. The grouting sequence is TC1 and TC2 first, then ZJ1 and ZJ2, and then ZJ3 and ZJ4.

[0037] For example, the opening diameter of the grouting hole is a first diameter. A protective casing is used for the loose layer and backfill layer, with an outer diameter of a second diameter, smaller than the first diameter. By installing the casing, mechanical support prevents hole wall collapse. The smooth inner wall of the casing facilitates the directional flow of grout along the casing, ensuring precise injection of grout into the target area and preventing radial seepage into ineffective areas, thereby improving grout utilization. Furthermore, the final grouting hole diameter formed in the rock layer is a third diameter, smaller than the second diameter.

[0038] In some embodiments, constructing the cutoff wall in step S3 specifically includes: S31. Construction of low-level retaining walls; S32, Low-pressure filling grouting; S33, High-pressure joint grouting.

[0039] The intermittent grouting process is adopted, and step S31 specifically includes: feeding aggregate into the guide water tunnel to form a barrier to intercept the grout. For example... Figure 4 and Figure 5As shown, aggregates are delivered to the water-guiding tunnel through orifices TC3 and TC4. The aggregates can be gravel or crushed stone. The aggregates pre-fill the tunnel space to form a physical skeleton structure. During subsequent grouting, the grout seeps into the gaps between the aggregates, forming a high-strength stone body. The stone body is more compact, which can effectively reduce water permeability channels. The aggregate layer can prevent the grout from spreading to distant places, avoiding poor grouting effect due to excessive grout loss. The physical barrier formed by the aggregate accumulation can resist the erosion of groundwater flow and prevent the pure grout from being washed away before it solidifies. The aggregates occupy part of the space, which can reduce the amount of grout required for pure grouting and save cement costs. As an inexpensive filling material, the use of aggregates in combination with cement grout is more economical and efficient than pure grouting.

[0040] Further, step S32 specifically includes: grouting the water channel according to the preset grouting holes to form a shape such as... Figure 5 The grouting stone body shown is used to construct a cutoff wall.

[0041] Furthermore, step S33 specifically includes: high-pressure grouting of the internal gaps of the grouting stone body to eliminate micro-seepage channels, improve the overall density of the stone body, and promote the tight bonding between the grout and aggregate, avoiding uneven strength of the cutoff wall due to local voids. After high-pressure grouting, the permeability coefficient of the stone body is reduced, which can effectively block the seepage of dynamically replenished water sources. High-pressure grouting can eliminate hidden defects and reduce the risk of stone body erosion or chemical dissolution caused by long-term seepage; the high-quality cutoff wall formed in one step can reduce the frequency of subsequent grouting and save on operation and maintenance costs.

[0042] This invention employs a combination of aggregate and grouting, which can adapt to complex geological conditions. When the tunnel collapses severely or there are large cavities, pure grouting may not be able to completely fill the gaps. However, the aggregate can first form a supporting structure, which is then reinforced by grouting. The aggregate can absorb some of the grouting pressure, thus preventing further collapse of the loose surrounding rock caused by high-pressure grouting.

[0043] Furthermore, step S3 also includes: S34, based on the grouting effect inspection, performing grouting in weak areas of the cutoff wall. By investigating and analyzing the density of the grout body at the top, weak areas within the grout body are identified, and high-pressure grouting is performed to ensure that the cutoff wall has no dead corners for leakage. A one-time grouting can extend the service life of the cutoff wall and prevent tiny gaps from potentially expanding into seepage channels under long-term water pressure, thereby improving the reliability of the cutoff wall.

[0044] Regarding the grouting process, the grouting material of this invention is mainly cement-fly ash slurry. For example, low-pressure filling grouting uses cement-fly ash slurry with a water-cement ratio of 0.6:1 to 0.8:1.

[0045] Furthermore, the high-pressure joint grouting uses a cement-fly ash slurry with a water-cement ratio of 0.8:1 to 1:1, and selectively adds polymer materials or accelerators to the slurry. It is understood that the water-cement ratio of the slurry used for low-pressure filling grouting is lower than that used for high-pressure joint grouting. A lower water-cement ratio makes the slurry viscous and has moderate fluidity, suitable for large-volume filling, and can reduce residual voids between aggregates; a higher cement content can improve the compressive strength of the solidified aggregate, providing a stable foundation for subsequent high-pressure grouting. A higher water-cement ratio enhances the fluidity of the slurry, facilitating penetration into micron-level cracks and compensating for the penetration blind spots of low-pressure grouting. During the high-pressure grouting stage, a small amount of organic polymer materials can be used to solve the problem of filling small cracks. Of course, when supplementing weak areas in step S34, accelerators or polymer materials can also be added to the slurry to improve the filling effect.

[0046] Considering the diffusion and dilution effects of pressurized water accumulation, the grout preparation design specifies that cement and fly ash each account for 50% of the solid phase, with admixtures comprising 0.3%–0.5%. To ensure the quality of the water cutoff construction, a small amount of organic polymer materials (such as Tiandi Bottom Water Blocking 101) can be used. Depending on the specific conditions revealed by the grouting holes, it may be necessary to appropriately reduce the water-cement ratio, add an accelerator to the grout, and add a small amount of crushed stone to promote rapid solidification and early strength of the grout, thereby reducing grout loss.

[0047] Before grouting, prepare grouting materials according to the estimated grouting volume to ensure the continuity of subsequent construction and improve project efficiency.

[0048] Based on the width, height, and other dimensions of the underground goaf diversion tunnel, the solid volume V of the cutoff wall is calculated. The grouting volume for cutoff grouting treatment can be estimated using the following formula: In the formula: Q – Required grouting volume for the treatment area; λ—Ineffective loss coefficient of slurry, with a water accumulation space of 0.35; V—Grouting space volume; η—slurry separation rate, taken as 0.8.

[0049] In some embodiments, for step S4, the inspection step includes drilling at least two inspection holes, performing core sampling, water pressure testing and imaging detection respectively, and comprehensively evaluating the density and top connection of the stone body.

[0050] Understandably, traditional grouting quality inspection often relies on a single method, which can easily lead to biased evaluations due to technical limitations. For example, water pressure testing alone is insufficient to determine the specific location of leaks and the morphology of internal defects in the grout body; core sampling alone is limited to point samples and cannot reflect the overall distribution of the grout body. This invention employs a complementary triple inspection method. The three methods work together to achieve a comprehensive evaluation from microscopic density to macroscopic water-blocking performance and continuous interface morphology, ensuring no quality blind spots are missed. The construction of at least two inspection boreholes aims to eliminate single-point random errors through multi-point data comparison, ensuring the reliability of the evaluation results. The inspection in step S4 provides precise guidance for the reinforcement in step S5. Through comprehensive analysis of core sampling, water pressure, and imaging, the specific type of quality problem (such as insufficient density, voids at the top, and internal cracks) and its precise location can be accurately determined. Based on the test results of step S4, the reinforcement can be directly targeted at the identified weak areas. The reinforcement hole position, grouting pressure, and grout type can be determined as needed to achieve precise targeted treatment, ensuring that the reinforcement is efficient and economical, and ultimately ensuring that the cutoff wall meets the designed density and water-blocking standards.

[0051] like Figure 4 As shown, two inspection boreholes, labeled JY1 and JY2, were drilled for the cutoff wall construction. Core sampling, water pressure testing, and grouting spatial imaging were used to investigate and analyze the density and roof contact of the solidified structure, thus verifying the effectiveness of the grouting and water interception. Core sampling yielded samples of the solidified rock mass, allowing for observation of its continuity and strength, and verifying the grouting results. Quantitative testing of the cutoff wall's permeability coefficient verified its water-blocking performance. High-definition borehole imaging identified internal cavities or cracks in the solidified rock mass, enabling precise location of weak areas for timely repair and preventing water inrush disasters caused by cutoff wall failure after mine commissioning.

[0052] Furthermore, regarding step S5, additional grouting holes can be added based on the grouting and water-cutting effect testing results to reinforce and strengthen the cutoff wall. During reinforcement, low-viscosity, high-permeability polymer materials can be selectively added to the grout. Using these materials significantly expands the penetration radius, allowing rapid penetration into micro-channels not covered by previous grouting (such as fissures in the surrounding rock and pores within the stone body), achieving capillary-like all-around filling. This significantly improves the sealing effect and completely blocks hidden seepage paths. Low-viscosity, high-permeability polymer materials typically possess rapid reaction and solidification characteristics. After injection into the defective area, they solidify quickly, significantly shortening the reinforcement operation time. Simultaneously, the solidified material exhibits high bonding strength with the stone body and surrounding rock, tightly binding the originally loose defective area to the surrounding qualified structure, improving the overall structural integrity of the cutoff wall and preventing later cracking caused by the detachment of the reinforced area from the original structure. By timely replenishing and reinforcing the cutoff wall, one-time precise treatment can be achieved, reducing the waste of materials and time caused by rework, improving the quality of the cutoff wall, ensuring the long-term safe use of the roadway, and reducing subsequent maintenance investment.

[0053] In some embodiments, the rapid sealing and water interception method for water diversion tunnels further includes: setting up water level monitoring boreholes in the tunnel area outside the water interception wall to monitor changes in water level in real time and evaluate the water interception effect.

[0054] Specifically, after the water diversion tunnel is sealed and the water is intercepted, a water level monitoring borehole is designed at a suitable location in the tunnel area outside the treatment area to establish an online monitoring station for real-time dynamic monitoring of water accumulation in the tunnel. By confirming whether the water level stabilizes or decreases after the water interception, it can be determined whether the water diversion channel is completely blocked. This step can also serve as a way to verify the effectiveness of the water interception. By assessing the interception effect through water level monitoring, it can be determined whether there is leakage in the interceptor wall and whether reinforcement is needed. By constructing the interceptor wall and draining the accumulated water in the work area outside the interceptor wall, the difficulty of drainage can be greatly reduced while eliminating the threat of large-volume water hazards, provided that the supply is cut off.

[0055] The present invention provides a rapid water-blocking and interception method for water-diversion tunnels. Based on the distribution characteristics of water-diversion tunnels and their relationship with the mine working space, the method involves investigating and analyzing the surrounding rock and water accumulation in the underground goaf water-diversion tunnel space, rationally selecting the location of the cutoff wall, and using grouting for interception. This achieves rapid water blocking and interception of the water-diversion tunnel, providing a safe and efficient solution for quickly removing large volumes of water and strongly replenishing old working water in mining operations. It can effectively eliminate the water hazard threat of high-flow-rate water-diversion tunnels. By designing a grouting and water-blocking effect verification step for the cutoff wall, it is beneficial to take corresponding water-blocking and reinforcement measures based on the effect verification results, thereby ensuring the quality of the cutoff wall and improving the reliability of water blocking and interception.

[0056] The sealing technology of this invention is applicable to the rapid sealing and interruption of water supply channels in underground and open-pit coal mines, metal mines, etc., and has technical advantages such as controlling the intensity of water supply in a short time and reducing mine drainage costs. By cutting the path, the source of water supply from old workings is blocked, significantly reducing the investment in the treatment of old workings water in underground mining areas and the drainage costs. It reduces the pressure on the existing mine drainage system without affecting its normal operation, and is significantly superior to traditional methods for treating old workings water. While achieving rapid sealing, it also considers both treatment effectiveness and cost control.

[0057] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for rapidly sealing and cutting off water in a water diversion tunnel, characterized in that, Includes the following steps: S1. By using multiple exploratory boreholes and combining borehole imaging technology, the three-dimensional spatial morphology, surrounding rock integrity, and water accumulation status of the water diversion tunnel are obtained. S2. Based on the exploration results, select a roadway section with intact surrounding rock and far from the mining boundary as the location for the cutoff wall construction, and design a grouting hole layout scheme for phased construction. S3. The aggregate is fed in sequence to form a low-level retaining wall, low-pressure filling and grouting are used to form a stone body, and high-pressure joint grouting is used to compact the joint. S4. By inspecting the boreholes, core samples of the grouting stone body are taken, water pressure tests are conducted, and imaging detection is performed to assess the compactness of the cutoff wall. S5. Based on the test results, reinforce the weak areas.

2. The method for rapid sealing and water interception of a water diversion tunnel according to claim 1, characterized in that, The plurality of the aforementioned detection boreholes include at least a first type of borehole that also serves as a grouting hole and a second type of borehole that also serves as an aggregate feeding hole.

3. The method for rapid sealing and water interception of a water diversion tunnel according to claim 1, characterized in that, In step S2, the grouting hole layout scheme for phased construction specifically includes: The position and spacing of the grouting holes in the next stage are dynamically adjusted based on the grouting diffusion situation in the previous stage. The spacing ranges from 5 to 15 meters, and the spacing increases with the slope.

4. The method for rapid sealing and water interception of a water diversion tunnel according to claim 1, characterized in that, In step S3, the aggregate is gravel or crushed stone, and the aggregate is fed to form a physical framework that intercepts the diffusion of slurry.

5. The method for rapid sealing and water interception of a water diversion tunnel according to claim 1, characterized in that, In step S3, the low-pressure filling grouting uses cement fly ash slurry with a water-cement ratio of 0.6:1 to 0.8:

1.

6. The method for rapid sealing and water interception of a water diversion tunnel according to claim 5, characterized in that, In step S3, the high-pressure joint grouting uses cement fly ash slurry with a water-cement ratio of 0.8:1 to 1:1, and the slurry selectively contains polymer materials or quick-setting agents.

7. The method for rapid sealing and water interception of a water diversion tunnel according to claim 1, characterized in that, In step S4, the inspection steps include drilling at least two inspection holes, performing core sampling, water pressure testing, and imaging detection respectively, and comprehensively evaluating the density and top contact of the stone body.

8. The method for rapid sealing and water interception of a water diversion tunnel according to any one of claims 1-7, characterized in that, Also includes: Water level monitoring boreholes are installed in the alleyway area outside the cutoff wall to monitor changes in water level in real time and assess the effectiveness of the water interception.

9. The method for rapid sealing and water interception of a water diversion tunnel according to any one of claims 1-7, characterized in that, The cutoff wall is constructed at a distance of no less than 100m from the mining boundary and avoids the roadway collapse zone and concentrated stress zone.

10. The method for rapid sealing and water interception of a water diversion tunnel according to any one of claims 1-7, characterized in that, In step S5, low-viscosity, high-permeability polymer materials may be selectively added to the grout used for reinforcement.

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