Negative pressure and high pressure cooperation inducing device

Abstract

The application discloses a negative pressure and high pressure cooperation inducing device, which comprises an inner tube and an outer tube coaxially sleeved together; the inner tube and the outer tube are coaxially arranged in an inducing hole; a plurality of outer sealing plugs are coaxially and spacedly sleeved on the outer tube outside the outer tube, and are used for dividing the inducing hole into a plurality of independent spaces in the axial direction; a plurality of communication holes are formed on the outer tube between two adjacent outer sealing plugs; three inner sealing plugs are spacedly arranged from front to back outside the inner tube and inside the outer tube; the three inner sealing plugs divide the inner part of the outer tube into three independent sealing sections from front to back, wherein the front section is a negative pressure section, the second section is a normal pressure section, and the third section at the rear end is a high pressure section; after the inner sealing plugs are discharged, the inner tube can move backward in the outer tube by a section, and the negative pressure section, the normal pressure section and the high pressure section move backward by a section in sequence. By adopting the device, the diffusion range and path of slurry can be induced and controlled, the uniformity and pertinence of slurry diffusion are improved, and the reinforcement effect of surrounding rock is ensured.

Description

Technical Field

[0001] This invention belongs to the field of tunnel grouting reinforcement technology, specifically relating to a negative pressure and high pressure combined induction device. Background Technology

[0002] Tunnel projects have extensively traversed areas with complex geological conditions, including weak and fractured surrounding rock, water-rich strata, and karst development zones. These areas have poor geological stability, weak self-supporting capacity of the surrounding rock, and are often accompanied by groundwater seepage. During tunnel excavation, these areas are highly susceptible to geological disasters such as surrounding rock collapse, tunnel face instability, and sudden water and mud inrushes. These disasters not only seriously threaten the lives of construction workers but also lead to project delays, increased investment, and even affect the structural durability of the tunnel during its operational phase.

[0003] To address the safety challenges of tunnel construction under complex geological conditions, grouting reinforcement technology, as an effective method of advanced support and surrounding rock improvement, is widely used in tunnel engineering. Its core principle involves injecting grout into fissures and pores in the surrounding rock. After solidification, the grout forms a cementitious body with a certain strength and integrity, thereby improving the compressive strength, impermeability, and integrity of the surrounding rock, blocking groundwater seepage channels, and providing a safe and stable geological environment for tunnel excavation.

[0004] Currently, commonly used grouting technologies in tunnel engineering mainly include advanced small-diameter pipe grouting, pipe roof grouting, and curtain grouting. However, existing grouting technologies still have many technical shortcomings in practical applications, making it difficult to meet the precise reinforcement requirements under complex geological conditions: Firstly, the grouting range and path are difficult to control precisely, easily leading to uneven grout diffusion, insufficient or excessive grouting in some areas, resulting in poor surrounding rock reinforcement and the continued risk of collapse in some areas. Excessive grouting also wastes materials and increases construction costs. Secondly, existing technologies often employ a blind grouting mode, lacking effective induction and guidance of the grout diffusion process. When multiple fracture channels exist in the surrounding rock, the grout easily flows away along channels with lower resistance, failing to... First, the effective filling of cracks and pores in the target reinforcement area reduces the targeting and effectiveness of grouting reinforcement. Second, in water-rich strata, the flow of groundwater will significantly affect the setting time and diffusion range of the grout. Existing grouting technology lacks effective measures to deal with groundwater interference, which can easily lead to problems such as grout dilution and insufficient setting strength, resulting in grouting reinforcement failure and inability to effectively block groundwater seepage. Third, existing grouting equipment and processes are relatively complex, the construction process is cumbersome, the operating skills of construction personnel are required to be high, and the construction efficiency is low, making it difficult to meet the needs of rapid construction of large-scale tunnel projects. Summary of the Invention

[0005] The purpose of this invention is to provide a negative pressure and high pressure combined induction device, which can induce and control the diffusion range and path of slurry, improve the uniformity and targeting of slurry diffusion, and ensure the effect of surrounding rock reinforcement.

[0006] The present invention adopts the following technical solution: a negative pressure and high pressure combined induction device, comprising an inner tube and an outer tube coaxially sleeved together; both ends of the inner tube and the outer tube are open for coaxial placement within the induction hole; Multiple outer sealing plugs are sleeved at intervals along the axial direction on the outer tube to divide the induction hole into multiple independent spaces in the axial direction; multiple connecting holes are opened on the outer tube between two adjacent outer sealing plugs. Outside the inner tube and inside the outer tube, there are three inner sealing plugs spaced apart from front to back; the three inner sealing plugs divide the inside of the outer tube into three independently sealed sections from front to back, of which the first section is a negative pressure section, the second section is a normal pressure section, and the third section is a high pressure section. After the inner sealing plug is vented, the inner tube can move backward a certain distance inside the outer tube, and the negative pressure section, normal pressure section and high pressure section move backward a certain distance in sequence.

[0007] Furthermore, the inner cavity of the inner tube is three independent axial channels, namely a negative pressure tube, a high pressure tube, and an inner sealing plug conduit; the negative pressure tube is connected to the negative pressure section at the front end and is used to draw gas from the negative pressure section. The front end of the high-pressure pipe is connected to the high-pressure section and is used to fill the high-pressure section with high-pressure gas. The inner sealing plug conduit is connected to three inner sealing plugs and is used to inflate and deflate the inner sealing plugs.

[0008] Furthermore, each outer sealing plug is connected to an outer sealing plug conduit, which is used to inflate the outer sealing plug with air so that the outer sealing plug fits tightly against the inner wall of the induction hole. Furthermore, the position of the inner sealing plug corresponds to the position of the outer sealing plug.

[0009] This invention also discloses a grouting method, based on the above-mentioned negative pressure and high pressure combined induction device, characterized by comprising the following steps: Step 1: According to the design requirements, make multiple boreholes on the tunnel face. Among two adjacent boreholes, one is a grouting hole and the other is an induction hole. Place a grouting pipe in the grouting hole and a negative pressure and high pressure combined induction device in the induction hole. Step 2: The outer sealing plug guide tube and the inner sealing plug guide tube are inflated with air into the outer sealing plug and the inner sealing plug respectively. The outer wall of the outer sealing plug is tightly attached to the inner wall of the induction hole, dividing the induction hole into multiple independent spaces in the axial direction; the outer wall of the inner sealing plug is tightly attached to the inner wall of the outer tube, dividing the outer tube into independent negative pressure section, normal pressure section and high pressure section from front to back. Step 3: The negative pressure pipe draws air into the negative pressure section to create a negative pressure state; the high pressure pipe fills the high pressure section with air to create a high pressure state. Step 4: Grout is injected into the bottom of the grouting hole through the grouting pipe. The grout penetrates into the formation in the negative pressure section from the grouting hole. In the normal pressure section and the high pressure section, the grout only penetrates into the formation in the negative pressure section, thus completing the grouting of the formation in the negative pressure section. Step 5: Stop grouting in the grouting pipe, stop suction in the negative pressure section and air supply in the high pressure section, and release the gas in the three inner sealing plugs through the inner sealing plug conduit; move the inner pipe backward a section, and move the negative pressure section, normal pressure section and high pressure section backward a section in sequence; at the same time, the grouting pipe retracts a section. Step 6: Repeat step 4 to complete the grouting of the strata in the negative pressure section area; Step 7: Repeat steps 5 and 6 to complete the grouting of the entire area.

[0010] Furthermore, the front ends of the grouting pipe and the negative pressure and high pressure cooperating induction device are close to the bottom of the hole, and a backward grouting method is adopted.

[0011] The beneficial effects of this invention are as follows: 1. A negative pressure section, a normal pressure section, and a high pressure section are set inside the induction hole. Under the action of negative pressure, the grout in the grouting hole adjacent to the induction hole quickly and uniformly permeates towards the area where the negative pressure section is located. Furthermore, since the areas sequentially connected to the negative pressure section are the normal pressure section and the high pressure section, the high pressure section ensures that the grout does not permeate to other areas at the rear, effectively constraining the grout diffusion range. 2. An inner sealing plug conduit is used to inflate or deflate the inner sealing plug. After deflation, the inner tube can move backward, sequentially enclosing the negative pressure zone along the entire length of the induction hole, facilitating on-site construction. 3. The inner cavity of the inner tube consists of three independent axial channels. Sealing, negative pressure, and high pressure are achieved using a single tube, resulting in a simple structure and eliminating the need for frequent disassembly and reassembly of external equipment, thus improving work efficiency. Attached Figure Description

[0012] Figure 1 This is a schematic diagram of a negative pressure and high pressure combined induction device; Figure 2 This is a top view of a negative pressure and high pressure combined induction device; Among them: 1. Formation 2. Outer pipe 3. Outer sealing plug 4. Outer sealing plug conduit 5. Inner pipe 6. Inner sealing plug 7. Drill hole. Detailed Implementation

[0013] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0014] This invention discloses a negative pressure and high pressure combined induction device, such as... Figure 1 and 2 As shown, it includes an inner tube 5 and an outer tube 2 coaxially sleeved together; both ends of the inner tube 5 and the outer tube 2 are open, for coaxial placement inside the induction hole, and the front end of the outer tube 2 is close to the front end of the induction hole.

[0015] Multiple outer sealing plugs 3 are sleeved around the outer tube 2 at intervals along its axial direction, and each outer sealing plug 3 is connected to an outer sealing plug conduit 4; the outer seals 3 are connected in series through the outer sealing plug conduit 4. The outer end of the outer sealing plug conduit 4 is connected to a pressurizing device; the outer sealing plug conduit 4 is used to inflate or deflate the outer sealing plugs 3 to seal or connect the borehole.

[0016] The inner cavity of the inner tube 5 has three independent axial channels, namely a negative pressure tube, a high pressure tube, and an inner sealing plug tube. A single tube achieves sealing, negative pressure, and high pressure, which is simple in structure and does not require frequent disassembly and assembly of external equipment, thus improving work efficiency.

[0017] Three inner sealing plugs 6 are coaxially fitted outside the inner tube 5 and inside the outer tube 2. These three inner sealing plugs 6 are arranged at intervals from front to back along the direction of the inner tube 5, with the foremost inner sealing plug 6 located near the front end of the inner tube 5. These three inner sealing plugs 6 divide the inner tube 5 axially into three enclosed spaces: the front section is a negative pressure section, the second section is a normal pressure section, and the rear section is a high pressure section. The negative pressure section is located at the very front end; that is, the outer sealing plug 3 and the inner sealing plug 6 enclose the front area of ​​the inner tube 5, the outer tube 2, and the induction hole to form a negative pressure section. The area where the negative pressure section is located is the target area. When grouting is performed in the grouting hole adjacent to the induction hole, because the target area is a negative pressure section, the grout in the grouting hole will quickly and evenly penetrate towards the negative pressure target area. Simultaneously, because the areas sequentially connected to the negative pressure section are the normal pressure section and the high pressure section, the high pressure section ensures that the grout will not penetrate into other areas at the rear, effectively constraining the grout diffusion range. An atmospheric pressure section is provided as a buffer zone to prevent direct connection between the high-pressure and negative-pressure sections. Under non-absolute sealing conditions, this allows the negative-pressure section to withstand lower pressure, preventing high-pressure gas from escaping into it. Both the inner sealing plug 6 and the outer sealing plug 3 are made of elastic material.

[0018] After the inner sealing plug 6 is vented, the inner tube 5 can move backward within the outer tube 2, with the negative pressure section, normal pressure section, and high pressure section moving backward in sequence. That is, the previous normal pressure section becomes the new negative pressure section, the previous high pressure section becomes the new normal pressure section, and the new section at the rear becomes the new high pressure section. After the inner sealing plug 6 is vented, new independent and sealed negative pressure sections, new normal pressure sections, and new high pressure sections are obtained. The inner tube 5 moves backward in sequence, obtaining new negative pressure sections, new normal pressure sections, and new high pressure sections, completing the grouting of all areas containing negative pressure sections.

[0019] On the inner sealing plug guide tube of the inner tube 5, multiple round holes are provided on the shell located at each inner sealing plug 6 to connect each inner sealing plug 6.

[0020] The front end of the inner tube 5 extends 10 cm beyond the first inner sealing plug 6. The distance between two adjacent inner sealing plugs 6 is 1 m, or the same as the distance between two adjacent outer sealing plugs 3. The inner sealing plug conduit connects the three inner sealing plugs 6, controlling the inflation and deflation of the inner sealing plugs to achieve segmental sealing of the inner part of the outer tube.

[0021] The present invention also discloses a grouting method, based on the above-mentioned negative pressure and high pressure combined induction device, comprising the following steps: Step 1: According to the design requirements, make multiple boreholes 7 on the tunnel face, select one as the grouting hole, and the surrounding boreholes adjacent to the grouting hole as the induction holes; place the grouting pipe in the grouting hole, and place a negative pressure and high pressure combined induction device in each induction hole. Step 2: The outer sealing plug conduit 4 and the inner sealing plug conduit inflate the outer sealing plug 3 and the inner sealing plug 6 respectively. The outer wall of the outer sealing plug 3 is tightly attached to the inner wall of the induction hole, dividing the induction hole into multiple independent spaces in the axial direction. The outer wall of the inner sealing plug 6 is tightly attached to the inner wall of the outer tube 2, dividing the outer tube 2 into independent negative pressure section, normal pressure section and high pressure section from front to back. Step 3: The negative pressure pipe draws air into the negative pressure section to create a negative pressure state; the high pressure pipe fills the high pressure section with air to create a high pressure state. Step 4: Grout is injected into the bottom of the grouting hole through the grouting pipe. The grout penetrates into the formation 1 in the negative pressure section area through the grouting hole. The normal pressure section and the high pressure section ensure that the grout only penetrates into the formation in the negative pressure section area, thus completing the grouting of the formation in the negative pressure section area. Step 5: Stop grouting in the grouting pipe, stop suction in the negative pressure section and air supply in the high pressure section, and release the gas in the three inner sealing plugs 6 through the inner sealing plug conduit; move the inner pipe 5 backward a section, and the negative pressure section, normal pressure section and high pressure section move backward a section in sequence; at the same time, the grouting pipe retracts a section. Step 6: Repeat step 4 to complete the grouting of the strata in the negative pressure section area; Step 7: Repeat steps 5 and 6 to complete the grouting of the entire area.

[0022] In this invention, a grouting hole is selected, and the adjacent surrounding boreholes are selected as induction holes. The grouting hole and the induction hole are used in conjunction for grouting. Retreating grouting is employed in the grouting hole, while a negative pressure and high pressure induction device is installed in the induction hole. The induction hole is equipped with a negative pressure section, a normal pressure section, and a high pressure section. Under the action of negative pressure, the grout in the grouting hole adjacent to the induction hole rapidly and uniformly permeates towards the area where the negative pressure section is located. Furthermore, since the areas sequentially connected to the negative pressure section are the normal pressure section and the high pressure section, the high pressure section ensures that the grout does not permeate to other areas downstream, thus achieving the induction and control of the grout diffusion range and path, improving the uniformity and targeting of grout diffusion, and ensuring the effectiveness of surrounding rock reinforcement.

Claims

1. A negative pressure and high pressure combined induction device, characterized in that, It includes an inner tube (5) and an outer tube (2) that are coaxially sleeved together; both ends of the inner tube (5) and the outer tube (2) are open and are used to be coaxially set in the induction hole; Outside the outer tube (2), a plurality of outer sealing plugs (3) are sleeved at intervals along its axial direction to divide the induction hole into a plurality of independent spaces in the axial direction; a plurality of connecting holes are provided on the outer tube (2) between two adjacent outer sealing plugs (3); Outside the inner tube (5) and inside the outer tube (2), three inner sealing plugs (6) are arranged at intervals from front to back; the three inner sealing plugs (6) divide the interior of the outer tube (2) into three independently sealed sections from front to back, wherein the first section at the front end is a negative pressure section, the second section is a normal pressure section, and the third section at the rear end is a high pressure section; After the inner sealing plug (6) is vented, the inner tube (5) can move backward a section inside the outer tube (2), and the negative pressure section, normal pressure section and high pressure section move backward a section in sequence; The inner cavity of the inner tube (5) consists of three independent axial channels, namely a negative pressure tube, a high pressure tube, and an inner sealing plug conduit; the negative pressure tube is connected to the negative pressure section at the front end and is used to draw gas from the negative pressure section. The front end of the high-pressure pipe is connected to the high-pressure section and is used to fill the high-pressure section with high-pressure gas. The inner sealing plug conduit is connected to three inner sealing plugs (6) and is used to inflate and deflate the inner sealing plugs (6); Each of the external sealing plugs (3) is connected to the external sealing plug conduit (4), which is used to inflate the external sealing plug (3) with air so that the external sealing plug (3) fits tightly against the inner wall of the induction hole; The position of the inner sealing plug (6) corresponds to the position of the outer sealing plug (3).

2. A grouting method, based on the negative pressure and high pressure combined induction device as described in claim 1, characterized in that, Includes the following steps: Step 1: According to the design requirements, make multiple boreholes (7) on the tunnel face. Among two adjacent boreholes, one is a grouting hole and the other is an induction hole. Place a grouting pipe in the grouting hole and place a negative pressure and high pressure combined induction device in the induction hole. Step 2: The outer sealing plug conduit (4) and the inner sealing plug conduit are inflated with air into the outer sealing plug (3) and the inner sealing plug (6) respectively. The outer wall of the outer sealing plug (3) is tightly attached to the inner wall of the induction hole, dividing the induction hole into multiple independent spaces in the axial direction. The outer wall of the inner sealing plug (6) is tightly attached to the inner wall of the outer tube (2), dividing the outer tube (2) into independent negative pressure section, normal pressure section and high pressure section from front to back. Step 3: The negative pressure pipe draws air into the negative pressure section to create a negative pressure state; the high pressure pipe fills the high pressure section with air to create a high pressure state. Step 4: Grout is injected into the bottom of the grouting hole through the grouting pipe. The grout penetrates into the stratum (1) in the negative pressure section from the grouting hole. The normal pressure section and the high pressure section ensure that the grout only penetrates into the stratum in the negative pressure section, thus completing the grouting of the stratum in the negative pressure section. Step 5: Stop grouting in the grouting pipe, stop suction in the negative pressure section and gas delivery in the high pressure section, and release the gas in the three inner sealing plugs (6) through the inner sealing plug conduit; move the inner pipe (5) backward a section, and the negative pressure section, normal pressure section and high pressure section move backward a section in sequence; at the same time, the grouting pipe moves backward a section. Step 6: Repeat step 4 to complete the grouting of the strata in the negative pressure section area; Step 7: Repeat steps 5 and 6 to complete the grouting of the entire area.

3. The grouting method as described in claim 2, characterized in that, The front ends of the grouting pipe and the negative pressure and high pressure combined induction device are close to the bottom of the hole, and a backward grouting method is adopted.

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