A mine grading grouting reinforcement device

Abstract

The application discloses a mine grading grouting reinforcement device and belongs to the technical field of grouting reinforcement. The mine grading grouting reinforcement device is characterized in that a sectional blocking device for separating a grouting pipe into at least two grouting sections along the length direction is arranged on the grouting pipe, a two-way safety valve is arranged on each grouting section of the grouting pipe, one end of the grouting pipe close to the hole bottom is closed, the two-way safety valve has a first opening pressure and a first closing pressure, the opening pressure of the two-way safety valve is greater than the grouting pressure of the sectional blocking device, the first closing pressure of the two-way safety valve is greater than the first opening pressure, and the first closing pressure of each two-way safety valve gradually increases from the hole opening to the hole bottom. In this way, a relatively independent grouting section can be formed in the drilling hole, the grouting pressure close to the hole opening of the grouting pipe is small, the grouting pipe is not prone to slurry running at the roadway surrounding rock fracture development position, the grouting pressure close to the hole bottom of the grouting pipe is greater, high-pressure deep-hole splitting grouting can be realized, and the grouting reinforcement effect of the roadway surrounding rock is better.

Description

Technical Field

[0001] This invention relates to a tunnel reinforcement device, and more specifically, to a mine-use graded grouting reinforcement device. Background Technology

[0002] As coal mining scale expands year by year, the geological conditions of mines are becoming increasingly complex, especially when roadways pass through sections of soft and fractured surrounding rock, making roadway support increasingly difficult. To ensure effective support of the surrounding rock, grouting reinforcement is often used for fractured surrounding rock. However, conventional grouting pipe grouting requires spraying a layer of concrete to seal the surrounding rock, which presents the following three problems:

[0003] (1) When spraying concrete, a large amount of concrete dust is dispersed in the tunnel, the surrounding construction environment is harsh, and the workers on site are very resistant.

[0004] (2) The jetting machine is very bulky, inconvenient to move and install, and requires a lot of labor intensity for workers;

[0005] (3) The pressure inside the grouting pipe is basically balanced along the axial direction. When the pressure inside the grouting pipe is too high, the grout is likely to run along the shallow surrounding rock fissures of the roadway. When the pressure inside the grouting pipe is too low, the grout is difficult to penetrate into the fine fissures of the surrounding rock deep in the roadway, and the high-pressure grouting effect cannot be achieved.

[0006] Currently, there are also graded and segmented grouting reinforcement technologies in existing technologies. For example, the "Complete System for Graded Controllable Anchor Bolt Grouting Support for Surrounding Rock Reinforcement" disclosed in Chinese Patent No. ZL201320736553.4 uses water-swellable anchor bolts to expand into sections, and uses the pressure-induced expansion and rupture of the grout-resistant membranes of different thicknesses on different sections of the grouting pipe to achieve segmented grouting. This method first performs bottom hole grouting, and then gradually increases the pressure to grout towards the roadway. In fact, the grouting pressure in the sections closer to the shallow surface of the roadway is actually greater, and the problem of high grouting pressure in the shallow surface of the roadway still exists. For example, Chinese Patent No. ZL202011279334.9 discloses a "segmented hollow grouting anchor cable device for geotechnical engineering." Its working mechanism is similar to the aforementioned patent application, but the difference lies in its use of segmented isolators with expanding and solidifying materials for segmentation. Grouting is achieved by rupturing pressure-regulating sealing sleeves with different pressure bearing ranges under grouting pressure. Regardless of whether the section closest to the roadway is grouted first or last, the pressure-regulating sealing sleeve cannot be resealed after rupture. Therefore, the grouting pressure in the shallow surrounding rock of the roadway remains equivalent to the pressure inside the grouting pipe, failing to solve the problem of high grouting pressure and grout leakage in the shallow surrounding rock of the roadway. Furthermore, using water-swellable sealing strips and expanding and solidifying materials to achieve segmentation results in poor controllability within the borehole and requires a certain reaction time to complete the expansion and segmentation, leading to low work efficiency.

[0007] Based on the aforementioned problems with existing technologies, it is necessary to design a mining segmented and graded grouting reinforcement device that can control the gradual increase of grouting pressure from the shallow surface of the roadway to the bottom of the hole. Summary of the Invention

[0008] 1. The technical problem that the invention aims to solve

[0009] The purpose of this invention is to overcome the aforementioned shortcomings of existing segmented grouting reinforcement technologies and provide a mine-use graded grouting reinforcement device. Using the technical solution of this invention, a segmented plugging device is used to segmentally plug the borehole, and a bidirectional safety valve is used to inject grout into each grouting segment. The opening pressure of the bidirectional safety valve is greater than the grouting pressure of the segmented plugging device, allowing relatively independent grouting segments to be formed within the borehole. This makes the segmented plugging of the borehole more direct and effective, with higher plugging efficiency, and the resulting plugging expansion body improves pull-out resistance. The closing pressure of the bidirectional safety valve is greater than the opening pressure, and the closing pressure of each bidirectional safety valve increases sequentially from the borehole opening to the bottom. This results in different grouting pressures for each grouting segment, with lower grouting pressure near the grouting pipe opening, reducing the risk of grout leakage in areas with developed rock fissures. The grouting pressure increases towards the bottom of the grouting pipe, enabling high-pressure deep-hole fracturing grouting and achieving better grouting reinforcement of the surrounding rock in the roadway.

[0010] 2. Technical Solution

[0011] To achieve the above objectives, the technical solution provided by the present invention is as follows:

[0012] A mining graded grouting reinforcement device of the present invention includes a grouting pipe, wherein the grouting pipe is provided with a segmented plug for dividing the grouting pipe into at least two grouting sections along its length. Each grouting section of the grouting pipe is provided with a bidirectional safety valve. The end of the grouting pipe near the bottom of the hole is closed. The grout inlet of the bidirectional safety valve is located inside the grouting pipe, and the grout outlet of the bidirectional safety valve is located outside the grouting pipe. The bidirectional safety valve has a first opening pressure and a first closing pressure. The first opening pressure of the bidirectional safety valve is greater than the grouting pressure of the segmented plug, and the first closing pressure of the bidirectional safety valve is greater than the first opening pressure. The first closing pressure of each of the bidirectional safety valves increases sequentially from the hole opening to the hole bottom.

[0013] Furthermore, the first opening pressure of each of the aforementioned bidirectional safety valves is the same.

[0014] Furthermore, a segmented plug is provided on the grouting pipe near the orifice, and a segmented plug is selectively provided on the grouting pipe near the bottom of the orifice.

[0015] Furthermore, the grouting pipe is composed of several pipe units connected by threads, and each pipe unit is equipped with at least one segmented plug and at least one two-way safety valve.

[0016] Furthermore, the length of each grouting section is 1 to 2 meters.

[0017] Furthermore, the segmented plugging device includes a sealing bag and a bag grouting valve. The sealing bag is located on the outer wall of the grouting pipe, and the bag grouting valve is installed at the communication hole between the grouting pipe and the sealing bag. The bag grouting valve has a second opening pressure and a second closing pressure. The second closing pressure of the bag grouting valve is greater than the second opening pressure. The second opening pressure of the bag grouting valve is lower than the first opening pressure of the bidirectional safety valve. The second closing pressure of the bag grouting valve is lower than the maximum expansion pressure that the sealing bag can withstand.

[0018] Furthermore, the structure of the bag grouting valve is the same as that of the two-way safety valve, both including a valve body, a first valve core assembly and a second valve core assembly. The valve body has a valve cavity that connects the grout inlet and the grout outlet. The first valve core assembly is located in the valve cavity on the side near the grout outlet, and the second valve core assembly is located in the valve cavity on the side near the grout inlet.

[0019] The first valve core assembly includes a first valve core adjusting rod, a first spring baffle, a first spring, and a first valve core. The first valve core adjusting rod is threaded to one end of the valve body. A first valve core shaft extends from the first valve core adjusting rod into the valve cavity. The first valve core is slidably sleeved on the first valve core shaft. The first spring acts between the first spring baffle on the first valve core shaft and the first valve core, so that the first valve core is in an elastic tendency to close the valve cavity.

[0020] The second valve core assembly includes a second valve core adjusting rod, a second spring baffle, a second spring, and a second valve core. The second valve core adjusting rod is threaded to the other end of the valve body. A second valve core shaft extends from the second valve core adjusting rod into the valve cavity. The second valve core is slidably sleeved on the second valve core shaft. The second spring acts between the second spring baffle on the second valve core shaft and the second valve core, so that the second valve core is in an elastic tendency to open the valve cavity.

[0021] Both the first valve core and the valve cavity, and the second valve core and the valve cavity, adopt a tapered surface mating structure that gradually decreases towards the center.

[0022] Furthermore, both the first valve core and the second valve core are frustoconical structures. The valve cavity has a first conical surface that mates with the first valve core on the side near the slurry outlet, and a second conical surface that mates with the second valve core on the side near the slurry inlet.

[0023] Furthermore, the second opening pressure of the sluice bag injection valve is 0MPa to 0.5MPa.

[0024] Furthermore, the grouting pipe is divided into five grouting sections by a segmented sealing device, which are sequentially arranged from the orifice to the bottom of the orifice as the first grouting section, the second grouting section, the third grouting section, the fourth grouting section, and the fifth grouting section. The bidirectional safety valve of the first grouting section is safety valve I, the bidirectional safety valve of the second grouting section is safety valve II, the bidirectional safety valve of the third grouting section is safety valve III, the bidirectional safety valve of the fourth grouting section is safety valve IV, and the bidirectional safety valve of the fifth grouting section is safety valve V. The first closing pressure of safety valve I is 1MPa to 2MPa, the first closing pressure of safety valve II is 2MPa to 3MPa, the first closing pressure of safety valve III is 3MPa to 4MPa, the first closing pressure of safety valve IV is 4MPa to 5MPa, and the first closing pressure of safety valve V is greater than or equal to 5MPa.

[0025] 3. Beneficial effects

[0026] Compared with existing known technologies, the technical solution provided by this invention has the following significant advantages:

[0027] (1) A mining graded grouting reinforcement device of the present invention includes a grouting pipe equipped with a segmented plugging device for dividing the grouting pipe into at least two grouting sections along its length. Each grouting section of the grouting pipe is equipped with a bidirectional safety valve. The end of the grouting pipe near the bottom of the borehole is closed. The bidirectional safety valve has a first opening pressure and a first closing pressure. The opening pressure of the bidirectional safety valve is greater than the grouting pressure of the segmented plugging device, and the first closing pressure of the bidirectional safety valve is greater than the first opening pressure. Furthermore, the first closing pressure of each bidirectional safety valve increases sequentially from the borehole opening to the bottom of the borehole. Thus, the borehole is segmented and plugged using the segmented plugging device, and grout is injected into each section using the bidirectional safety valve. Grouting is performed in sections. Because the opening pressure of the two-way safety valve is greater than the grouting pressure of the segmented plugging device, relatively independent grouting sections can be formed in the borehole first. The segmented plugging of the borehole is more direct and effective, and the plugging efficiency is higher. The formed plugging expansion body can improve the pull-out resistance. In addition, the grouting pressure of each grouting section is different. The grouting pressure is lower near the grouting pipe orifice, and the grouting pressure is not easy to escape in the fractured areas of the surrounding rock of the roadway. The grouting pressure is higher closer to the bottom of the grouting pipe orifice, which can realize high-pressure deep hole splitting grouting and the grouting reinforcement effect of the surrounding rock of the roadway is better. In addition, there is no need for shotcrete support before grouting, which does not worsen the surrounding construction environment and reduces the labor intensity of workers.

[0028] (2) The mine-use graded grouting reinforcement device of the present invention has the same opening pressure for each bidirectional safety valve, so that each grouting section can be grouted at the same time, and the grouting efficiency is higher; in addition, a segmented plug is provided on the grouting pipe near the hole opening, and a segmented plug is selectively provided on the grouting pipe near the bottom of the hole. The segmented plug can be used to directly seal the borehole opening, without the need to set up an additional sealing device.

[0029] (3) A mining graded grouting reinforcement device of the present invention has a grouting pipe made up of several pipe units connected by threads. Each pipe unit is provided with at least one segmented plug and at least one two-way safety valve, which can insert the grouting pipe into a long borehole, making it convenient for on-site construction in the roadway. In addition, the length of each grouting segment is 1 to 2 m, the borehole segment length is moderate, and the grouting pressure increases segment by segment towards the bottom of the hole, ensuring the grouting reinforcement effect of the roadway.

[0030] (4) A mining graded grouting reinforcement device of the present invention includes a segmented sealing device comprising a sealing bag and a bag grouting valve. The sealing bag is disposed on the outer wall of the grouting pipe, and the bag grouting valve is installed at the communication hole between the grouting pipe and the sealing bag. The bag grouting valve has a second opening pressure and a second closing pressure. The second closing pressure of the bag grouting valve is greater than the second opening pressure. The second opening pressure of the bag grouting valve is lower than the first opening pressure of the bidirectional safety valve. The second closing pressure of the bag grouting valve is lower than the maximum expansion pressure that the sealing bag can withstand. In this way, the bag grouting valve can open for grouting before the bidirectional safety valve, ensuring that the sealing bag can be opened when the grouting pipe is grouted under high pressure, thereby realizing segmented grouting. Moreover, the bag grouting valve can be closed when a certain sealing grouting pressure is reached to prevent the grouting pressure from being too high and damaging the sealing bag.

[0031] (5) The present invention provides a graded grouting reinforcement device for mining, wherein the structure of the bag grouting valve and the bidirectional safety valve are the same, both including a valve body, a first valve core assembly and a second valve core assembly. The valve core assembly is composed of a valve core adjusting rod, a spring baffle, a spring and a valve core, which can adjust the opening and closing pressure of the bag grouting valve and the bidirectional safety valve, and is flexible and convenient to use; and the structure of the bag grouting valve and the bidirectional safety valve is simple and compact, easy to manufacture, stable and reliable in operation, and can prevent grout backflow.

[0032] (6) A mining graded grouting reinforcement device of the present invention has a first valve core and a second valve core, both of which are frustoconical structures. The valve cavity has a first conical surface that cooperates with the first valve core on the side near the grout outlet, and a second conical surface that cooperates with the second valve core on the side near the grout inlet. In this way, the valve core can be opened or closed by utilizing the different pressure areas of the valve core frustoconical structure. The structure is simple and the operation is stable. Attached Figure Description

[0033] Figure 1 This is a schematic diagram of the structure of a graded grouting reinforcement device for mining according to the present invention;

[0034] Figure 2 This is a schematic diagram of the structure of a mine-use graded grouting reinforcement device of the present invention in a roadway borehole (segmented plugs in an unexpanded state);

[0035] Figure 3This is a schematic diagram of the structure of a mine-use graded grouting reinforcement device of the present invention in a roadway borehole (segmented sealing device grouting expansion state);

[0036] Figure 4 This is a schematic diagram of the structure of the sluice bag injection valve and the two-way safety valve in this invention (first valve core assembly in the normal pressure closed state);

[0037] Figure 5 This is a schematic diagram of the structure of the sluice bag grouting valve and the bidirectional safety valve in this invention (the first valve core assembly is in the grouting open state);

[0038] Figure 6 This is a schematic diagram of the structure of the sac grouting valve and the bidirectional safety valve in this invention (second valve core assembly in high-pressure closed state).

[0039] Explanation of the labels in the diagram:

[0040] 1. Grouting pipe; 1-1. Pipe unit; 2. Segmented plugger; 2-1. Sealing bag; 2-2. Bag grouting valve; 3. Two-way safety valve; 3A. Safety valve I; 3B. Safety valve II; 3C. Safety valve III; 3D. Safety valve IV; 3E. Safety valve V; 3-1. Valve body; 3-1-1. Valve cavity; 3-1-1a. First conical surface; 3-1-1b. Second conical surface; 3-1-2. Grout inlet; 3-1-3. Grout outlet; 3-2. First valve core adjusting rod; 3-2-1. First valve core shaft; 3-3. First spring baffle; 3-4. First spring; 3-5. First valve core; 3-6. Second valve core adjusting rod; 3-6-1. Second valve core shaft; 3-7. Second spring baffle; 3-8. Second spring; 3-9. Second valve core. Detailed Implementation

[0041] To further understand the content of this invention, a detailed description of the invention will be provided in conjunction with the accompanying drawings and embodiments.

[0042] [Example]

[0043] Combination Figures 1 to 3As shown in this embodiment, a mine-use graded grouting reinforcement device includes a grouting pipe 1. The grouting pipe 1 is equipped with a segmented plug 2 for dividing the grouting pipe 1 into at least two grouting sections along its length. A bidirectional safety valve 3 is provided on each grouting section of the grouting pipe 1. The end of the grouting pipe 1 near the bottom of the borehole is closed to ensure stable pressure within the grouting pipe 1. The inlet 3-1-2 of the bidirectional safety valve 3 is located inside the grouting pipe 1, and the outlet 3-1-3 is located outside the grouting pipe 1. Grout from the grouting pipe 1 is injected into the borehole through the bidirectional safety valve 3. The bidirectional safety valve 3 has a first opening pressure and a first closing pressure. The first opening pressure of the bidirectional safety valve 3 is greater than the grouting pressure of the segmented plug 2, meaning that under normal pressure, the bidirectional safety valve 3 is in a closed state. During grouting, the segmented plug 2 can expand first through grout injection. The formation of relatively independent grouting sections makes the segmented sealing of boreholes more direct and effective, with higher sealing efficiency. The resulting sealing expansion body can improve pull-out resistance. When the pressure inside the grouting pipe reaches the first opening pressure of the bidirectional safety valve 3, the bidirectional safety valve 3 opens, injecting grout into the grouting section. The first closing pressure of the bidirectional safety valve 3 is greater than the first opening pressure, and the first closing pressure of each bidirectional safety valve 3 increases sequentially from the borehole opening to the bottom of the borehole. Thus, as the grouting pressure increases, after reaching the first closing pressure of the bidirectional safety valve 3, the bidirectional safety valve 3 can automatically close, stopping the grouting. Because the grouting pressure of each grouting section is different, and the grouting pressure is lower near the borehole opening, grout is less likely to leak from areas with developed fractures in the surrounding rock of the roadway. The grouting pressure is higher closer to the bottom of the grouting pipe, enabling high-pressure deep-hole fracturing grouting and resulting in better reinforcement of the surrounding rock of the roadway.

[0044] In this embodiment, the first opening pressure of each bidirectional safety valve 3 is the same, enabling simultaneous grouting in each grouting section and resulting in higher grouting efficiency. A segmented plug 2 is provided on the grouting pipe 1 near the borehole opening, and selectively on the grouting pipe 1 near the bottom of the borehole. The segmented plug 2 can directly seal the borehole opening, eliminating the need for additional sealing devices; the structure is simple and easy to operate.

[0045] Reference Figures 1 to 3 As shown, to facilitate on-site construction, the grouting pipe 1 is composed of several pipe units 1-1 connected by threads. Adjacent pipe units 1-1 can be threaded together to form a complete grouting pipe 1, allowing it to be inserted into long boreholes, facilitating on-site construction within the roadway. Each pipe unit 1-1 is equipped with at least one segmented plugging device 2 and at least one two-way safety valve 3, for example... Figures 1 to 3 Each section of pipe unit 1-1 is equipped with a segmented plug 2 and a two-way safety valve 3 to facilitate the uniform fabrication of pipe unit 1-1. Preferably, the length of each grouting section is 1-2m, the borehole segment length is moderate, and the grouting pressure increases segment by segment towards the bottom of the hole, ensuring the grouting reinforcement effect of the roadway.

[0046] catch Figures 1 to 3 As shown, the mine-use graded grouting reinforcement device of this embodiment includes a segmented sealing device 2 comprising a sealing bag 2-1 and a bag grouting valve 2-2. The sealing bag 2-1 is located on the outer wall of the grouting pipe 1, and the bag grouting valve 2-2 is installed at the communication hole between the grouting pipe 1 and the sealing bag 2-1. The bag grouting valve 2-2 has a second opening pressure and a second closing pressure. The second closing pressure of the bag grouting valve 2-2 is greater than the second opening pressure, the second opening pressure of the bag grouting valve 2-2 is lower than the first opening pressure of the bidirectional safety valve 3, and the second closing pressure of the bag grouting valve 2-2 is lower than the maximum expansion pressure that the sealing bag 2-1 can withstand. In this way, the bag grouting valve 2-2 can open for grouting before the bidirectional safety valve 3, ensuring that the sealing bag 2-1 can be opened during high-pressure grouting of the grouting pipe, thus achieving segmented grouting; and when a certain sealing grouting pressure is reached, the bag grouting valve can be closed to prevent excessive grouting pressure from damaging the sealing bag 2-1. The aforementioned sealing bag 2-1 is preferably made of rubber and can be fitted onto the outside of each pipe unit 1-1, with both ends tightly sealed to the pipe wall. Compared to existing water-swellable sealing strips and expanding solidification materials, the aforementioned segmented sealing device 2 provides faster and more direct sealing, resulting in better sealing of the borehole.

[0047] In this embodiment, the aforementioned bag grouting valve 2-2 and the bidirectional safety valve 3 have the same structure and similar function. Both can be in a closed state under normal pressure, and can be opened first as the grouting pressure increases, and automatically closed after the grouting pressure reaches a set value. Figures 4 to 6As shown, the aforementioned bag grouting valve 2-2 and bidirectional safety valve 3 both include a valve body 3-1, a first valve core assembly, and a second valve core assembly. The valve body 3-1 has a grout inlet 3-1-2 and a grout outlet 3-1-3. The valve body 3-1 has a valve cavity 3-1-1 that connects the grout inlet 3-1-2 and the grout outlet 3-1-3. The first valve core assembly is located in the valve cavity 3-1-1 on the side near the grout outlet 3-1-3, and the second valve core assembly is located in the valve cavity 3-1-1 on the side near the grout inlet 3-1-2. The first valve core assembly includes a first valve core adjusting rod 3-2, a first spring baffle 3-3, a first spring 3-4, and a first valve core 3-5. The first valve core adjusting rod 3-2 is threadedly engaged with one end of the valve body 3-1, allowing it to be screwed in and out of the valve body 3-1. A first valve core shaft 3-2-1 extends from the first valve core adjusting rod 3-2 into the valve cavity 3-1-1. The first valve core 3-5 is slidably sleeved on the first valve core shaft 3-2-1. The first spring 3-4 acts between the first spring baffle 3-3 and the first valve core 3-5 on the first valve core shaft 3-2-1, causing the first valve core 3-5 to be in an elastic tendency to close the valve cavity 3-1-1. The second valve core assembly includes a second valve core adjusting rod 3-6, a second spring baffle 3-7, a second spring 3-8, and a second valve core 3-9. The second valve core adjusting rod 3-6 is threaded to the other end of the valve body 3-1 and can also be screwed in and out of the valve body 3-1. A second valve core shaft 3-6-1 extends from the second valve core adjusting rod 3-6 into the valve cavity 3-1-1. The second valve core 3-9 is slidably sleeved on the second valve core shaft 3-6-1. The second spring 3-8 acts between the second spring baffle 3-7 and the second valve core 3-9 on the second valve core shaft 3-6-1, causing the second valve core 3-9 to be in an elastic tendency to open the valve cavity 3-1-1. The first valve core 3-5 and the valve cavity 3-1-1, and the second valve core 3-9 and the valve cavity 3-1-1, both adopt a tapered surface fit structure that gradually narrows towards the center. The above design allows for adjustment of the opening and closing pressures of the bag grouting valve 2-2 and the two-way safety valve 3, providing flexibility and convenience in use. Furthermore, the bag grouting valve 2-2 and the two-way safety valve 3 have a simple and compact structure, are easy to manufacture, operate stably and reliably, and can prevent grout backflow. Specifically, the first spring 3-4 is a compression spring, with its two ends abutting between the first spring baffle 3-3 and the first valve core 3-5, respectively. The second spring 3-8 is a tension spring, with its two ends connected to the second spring baffle 3-7 and the second valve core 3-9, respectively. Under normal conditions (such as...), Figure 4 As shown, the first valve core 3-5 is in the closed state, and the second valve core 3-9 is in the open state. During the grouting process, the grout in the grouting pipe 1 enters the valve chamber 3-1-1 through the second valve core assembly near the grout inlet 3-1-2. As the grouting pressure increases, when the grouting pressure exceeds the pressure of the first spring 3-4 (i.e., the opening pressure), the first valve core 3-5 is pushed open, and the grout enters the sealing bag 2-1 or the grouting section between the borehole and the grouting pipe 1 through the grout outlet 3-1-3, forming... Figure 5 The state shown is as follows. The preload of the first spring 3-4 is adjusted by the first valve core adjusting rod 3-2. When the sealing bag 2-1 or the grouting section is filled with grout, the flow velocity of the grout in the valve cavity 3-1-1 decreases. As the grouting pressure further increases, the pressure on the side of the valve core with a larger pressure surface is greater than the pressure on the side with a smaller pressure surface. At this time, the second valve core 3-9 closes, the second spring 3-8 is stretched, and the internal and external pressures on both sides of the first valve core 3-5 tend to be balanced. Under the action of the first spring 3-4, the first valve core 3-5 also closes, forming... Figure 6 In the state shown, even if the grouting pressure in the grouting pipe 1 is removed, the second valve core 3-9 opens. However, because the pressure on the side of the first valve core 3-5 near the grout outlet 3-1-3 is high, the first valve core 3-5 remains closed to prevent grout backflow. The tension of the second spring 3-8 on the closed second valve core 3-9 can be adjusted by the second valve core adjusting rod 3-6. Specifically, in this embodiment, both the first valve core 3-5 and the second valve core 3-9 are frustoconical structures. The valve cavity 3-1-1 near the grout outlet 3-1-3 has a first conical surface 3-1-1a that mates with the first valve core 3-5, and the valve cavity 3-1-1 near the grout inlet 3-1-2 has a second conical surface 3-1-1b that mates with the second valve core 3-9. This allows the valve core to open or close by utilizing the different pressure-bearing areas of the frustoconical valve core, resulting in a simple structure and stable operation.

[0048] Reference Figure 2 and Figure 3As shown in this embodiment, in a specific implementation of a mine-use graded grouting reinforcement device, the second opening pressure of the bag grouting valve 2-2 can be set to 0MPa to 0.5MPa. Only a small grouting pressure is needed to open the bag grouting valve 2-2, so that the sealing bag 2-1 can be quickly grouted and expanded. The second closing pressure of the bag grouting valve 2-2 depends on the strength of the sealing bag 2-1. The grouting pipe 1 is divided into five grouting sections by the segmented plugging device 2. From the borehole opening to the bottom, these sections are sequentially designated as the first, second, third, fourth, and fifth grouting sections. The bidirectional safety valve 3 in the first grouting section is safety valve I 3A; in the second grouting section, it is safety valve II 3B; in the third grouting section, it is safety valve III 3C; in the fourth grouting section, it is safety valve IV 3D; and in the fifth grouting section, it is safety valve V 3E. Safety valves I 3A, II 3B, III 3C, IV 3D, and... The first opening pressure of safety valve V3E only needs to be slightly greater than the second opening pressure of bag grouting valve 2-2, such as 0.5MPa to 0.8MPa. The first closing pressure of safety valve I3A can be set to 1MPa to 2MPa, the first closing pressure of safety valve II3B can be set to 2MPa to 3MPa, the first closing pressure of safety valve III3C can be set to 3MPa to 4MPa, the first closing pressure of safety valve IV3D can be set to 4MPa to 5MPa, and the first closing pressure of safety valve V3E can be set to greater than or equal to 5MPa. In this way, the pressure at the outlet of the bidirectional safety valve 3 in each grouting section is sequentially: first section < second section < third section < fourth section < fifth section, realizing different grouting pressures in each section, thereby achieving the purpose of segmented and graded grouting within the grouting hole. Because the surrounding rock fissures are well-developed near the grouting pipe orifice, the grouting pressure is low, making it less prone to grout leakage; the surrounding rock fissures are less developed near the pressure at the bottom of the grouting pipe orifice, resulting in a higher grouting pressure, enabling high-pressure deep-hole fracturing grouting.

[0049] This invention provides a graded grouting reinforcement device for mines, which improves the working environment in roadways, reduces grouting procedures, and is easy to operate and use. Specifically, it has the following beneficial effects:

[0050] 1) No shotcrete support is needed before grouting, which does not worsen the surrounding construction environment and reduces the labor intensity of workers;

[0051] 2) The borehole is sealed in sections using a segmented plugging device. Grouting is injected into each grouting section using a two-way safety valve. The pressure inside the grouting pipe is set in stages along the axial direction of the grouting pipe. Relatively independent grouting sections can be formed in the borehole first. The segmented sealing of the borehole is more direct and effective, and the sealing efficiency is higher. The formed sealing expansion body can improve the pull-out resistance.

[0052] 3) The grouting pressure is low near the grouting pipe orifice, which can prevent the grout from running along the shallow surrounding rock fissures in the roadway;

[0053] 4) The closer to the bottom of the grouting pipe, the greater the grouting pressure, which can achieve high-pressure deep hole splitting grouting and better grouting reinforcement effect of the surrounding rock of the roadway.

[0054] The present invention and its embodiments have been described above illustratively. This description is not restrictive, and the figures shown are only one embodiment of the present invention; the actual structure is not limited thereto. Therefore, if those skilled in the art are inspired by this description and design similar structures and embodiments without departing from the spirit of the present invention, such designs should fall within the protection scope of the present invention.

Claims

1. A mining graded grouting reinforcement device, comprising a grouting pipe (1), wherein the grouting pipe (1) is provided with a segmented sealing device (2) for dividing the grouting pipe (1) into at least two grouting sections along its length, characterized in that: Each grouting section of the grouting pipe (1) is equipped with a two-way safety valve (3). The end of the grouting pipe (1) near the bottom of the hole is closed. The inlet (3-1-2) of the two-way safety valve (3) is located inside the grouting pipe (1), and the outlet (3-1-3) of the two-way safety valve (3) is located outside the grouting pipe (1). The two-way safety valve (3) has a first opening pressure and a first closing pressure. The first opening pressure of the two-way safety valve (3) is greater than the grouting pressure of the segmented plug (2). The first closing pressure of the two-way safety valve (3) is greater than the first opening pressure. The first closing pressure of each of the two-way safety valves (3) increases sequentially from the hole opening to the bottom of the hole. The segmented plugging device (2) includes a sealing bag (2-1) and a bag grouting valve (2-2). The sealing bag (2-1) is located on the outer wall of the grouting pipe (1). The bag grouting valve (2-2) is installed at the communication hole between the grouting pipe (1) and the sealing bag (2-1). The bag grouting valve (2-2) has a second opening pressure and a second closing pressure. The second closing pressure of the bag grouting valve (2-2) is greater than the second opening pressure. The second opening pressure of the bag grouting valve (2-2) is lower than the first opening pressure of the two-way safety valve (3). The second closing pressure of the bag grouting valve (2-2) is lower than the maximum expansion pressure that the sealing bag (2-1) can withstand. The slurry injection valve (2-2) and the bidirectional safety valve (3) have the same structure, both including a valve body (3-1), a first valve core assembly and a second valve core assembly. The valve body (3-1) has a valve cavity (3-1-1) that connects the slurry inlet (3-1-2) and the slurry outlet (3-1-3). The first valve core assembly is located in the valve cavity (3-1-1) on the side near the slurry outlet (3-1-3), and the second valve core assembly is located in the valve cavity (3-1-1) on the side near the slurry inlet (3-1-2). The first valve core assembly includes a first valve core adjusting rod (3-2), a first spring baffle (3-3), a first spring (3-4), and a first valve core (3-5). The first valve core adjusting rod (3-2) is threaded to one end of the valve body (3-1). A first valve core shaft (3-2-1) extends from the first valve core adjusting rod (3-2) into the valve cavity (3-1-1). The first valve core (3-5) is slidably sleeved on the first valve core shaft (3-2-1). The first spring (3-4) acts between the first spring baffle (3-3) and the first valve core (3-5) on the first valve core shaft (3-2-1), so that the first valve core (3-5) is in an elastic tendency to close the valve cavity (3-1-1). The second valve core assembly includes a second valve core adjusting rod (3-6), a second spring baffle (3-7), a second spring (3-8), and a second valve core (3-9). The second valve core adjusting rod (3-6) is threadedly engaged with the other end of the valve body (3-1). A second valve core shaft (3-6-1) extends from the second valve core adjusting rod (3-6) into the valve cavity (3-1-1). The second valve core (3-9) is slidably sleeved on the second valve core shaft (3-6-1). The second spring (3-8) acts between the second spring baffle (3-7) and the second valve core (3-9) on the second valve core shaft (3-6-1), so that the second valve core (3-9) is in an elastic tendency to open the valve cavity (3-1-1). The first valve core (3-5) and the valve cavity (3-1-1) and the second valve core (3-9) and the valve cavity (3-1-1) both adopt a tapered mating structure that gradually shrinks towards the center.

2. The mine-use graded grouting reinforcement device according to claim 1, characterized in that: The first opening pressure of each of the aforementioned two-way safety valves (3) is the same.

3. The mine-use graded grouting reinforcement device according to claim 1, characterized in that: A segmented plug (2) is provided on the grouting pipe (1) near the orifice, and a segmented plug (2) is selectively provided on the grouting pipe (1) near the bottom of the orifice.

4. The mine-use graded grouting reinforcement device according to claim 1, characterized in that: The grouting pipe (1) is formed by connecting several pipe units (1-1) by threads. Each pipe unit (1-1) is provided with at least one segmented plug (2) and at least one two-way safety valve (3).

5. The mine-use graded grouting reinforcement device according to claim 1, characterized in that: The length of each grouting section is 1~2m.

6. The mine-use graded grouting reinforcement device according to claim 1, characterized in that: Both the first valve core (3-5) and the second valve core (3-9) are frustoconical structures. The valve cavity (3-1-1) has a first conical surface (3-1-1a) that mates with the first valve core (3-5) on the side near the slurry outlet (3-1-3), and a second conical surface (3-1-1b) that mates with the second valve core (3-9) on the side near the slurry inlet (3-1-2).

7. The mine-use graded grouting reinforcement device according to claim 1, characterized in that: The second opening pressure of the slurry injection valve (2-2) is 0MPa~0.5MPa.

8. The mine-use graded grouting reinforcement device according to claim 1, characterized in that: The grouting pipe (1) is divided into five grouting sections by a segmented plug (2), which are, in order from the orifice to the bottom of the orifice, the first grouting section, the second grouting section, the third grouting section, the fourth grouting section, and the fifth grouting section. The bidirectional safety valve (3) of the first grouting section is safety valve I (3A), the bidirectional safety valve (3) of the second grouting section is safety valve II (3B), the bidirectional safety valve (3) of the third grouting section is safety valve III (3C), the bidirectional safety valve (3) of the fourth grouting section is safety valve IV (3D), and the bidirectional safety valve (3) of the fifth grouting section is safety valve V (3E). The first closing pressure of safety valve I (3A) is 1MPa~2MPa, the first closing pressure of safety valve II (3B) is 2MPa~3MPa, the first closing pressure of safety valve III (3C) is 3MPa~4MPa, the first closing pressure of safety valve IV (3D) is 4MPa~5MPa, and the first closing pressure of safety valve V (3E) is greater than or equal to 5MPa. MPa.

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